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Sample records for st lawrence estuary

  1. Turbulent nitrate fluxes in the Lower St. Lawrence Estuary, Canada

    NASA Astrophysics Data System (ADS)

    Cyr, Frdric; Bourgault, Daniel; Galbraith, Peter S.; Gosselin, Michel

    2015-03-01

    Turbulent vertical nitrate fluxes were calculated using new turbulent microstructure observations in the Lower St. Lawrence Estuary (LSLE), Canada. Two stations were compared: the head of the Laurentian Channel (HLC), where intense mixing occurs on the shallow sill that marks the upstream limit of the LSLE, and another station located about 100 km downstream (St. 23), more representative of the LSLE mean mixing conditions. Mean turbulent diffusivities and nitrate fluxes at the base of the surface layer for both stations were, respectively (with 95% confidence intervals): KHLC = 8.6>(3.2,19>) 10-3 m2 s-1,K23 = 4.4>(2.3,7.6>) 10-5 m2 s-1,FHLC = 95>(18,300>) mmol m-2 d-1, and F23 = 0.21>(0.12,0.33>) mmol m-2 d-1. Observations suggest that the interplay between large isopleth heaving near the sill and strong turbulence is the key mechanism to sustain such high turbulent nitrate fluxes at the HLC (two to three orders of magnitude higher than those at Station 23). Calculations also suggest that nitrate fluxes at the HLC alone can sustain primary production rates of 3.4>(0.6,11>) g C m-2 mo-1 over the whole LSLE, approximately enough to account for a large part of the phytoplankton bloom and for most of the postbloom production. Surfacing nitrates are also believed to be consumed within the LSLE, not leaving much to be exported to the rest of the Gulf of St. Lawrence. This article was corrected on 13 APR 2015. See the end of the full text for details.

  2. Cancer in beluga from the St. Lawrence estuary.

    PubMed Central

    Hammill, Mike O; Lesage, Véronique; Kingsley, Michael C S

    2003-01-01

    Martineau et al. (2002) reported that St. Lawrence beluga (SLB) have high cancer rates. Unfortunately, errors in their interpretation of the data have led them to overstate the importance of cancer and its links to environmental sources. PMID:12573920

  3. Denitrification in sediments of the Laurentian Trough, St. Lawrence Estuary, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Wang, Fenghai; Juniper, S. Kim; Pelegrí, Sílvia P.; Macko, Stephen A.

    2003-06-01

    The isotope pairing technique was used to obtain the first sedimentary denitrification rates for the St. Lawrence Estuary/Gulf system (Québec, Canada). Denitrification rates were measured on intact sediment cores collected at three stations down the slope of the Laurentian Trough at 103, 200 and 320 m depth. For samples collected in June 1997, total denitrification rates ranged from 1.8 to 3.3 μmol N m -2 h -1 among the three stations. Only 3-5% of the NO 3- consumed by the sediments was subsequently denitrified. Nitrification was the major source of NO 3- for denitrification, representing 56-79% of total denitrification rates. Sediment consumption of water column O 2 (102-187 μmol O 2 m -2 h -1) and NO 3- (13.9-25.5 NO 3- m -2 h -1) increased significantly downslope, as did total denitrification rates. Denitrification made a negligible (<0.2%) contribution to carbon mineralization in our cores, but may have a greater impact on the nitrogen cycle. In addition, data suggest the presence of a major dissimilatory nitrate sink in these sediments that far exceeds the requirements of denitrification. The latter observation is considered in terms of proposed interactions between the nitrogen cycle and metal reduction/oxidation. We conclude by considering limitations to the extrapolation of these data to annual and regional scale nitrogen budgets for the deep waters of the St. Lawrence Estuary.

  4. Trophic interactions in the St. Lawrence Estuary (Canada): Must the blue whale compete for krill?

    NASA Astrophysics Data System (ADS)

    Savenkoff, C.; Comtois, S.; Chabot, D.

    2013-09-01

    Inverse methodology was used to construct a mass-balance model of the Lower St. Lawrence Estuary (LSLE) for the 2008-2010 time period. Our first objective was to make an overall description of community structure, trophic interactions, and the effects of fishing and predation on the vertebrate and invertebrate communities of the ecosystem. A second objective was to identify other important predators of krill, and to assess if these compete with blue whales, listed as endangered under the Canadian Species at Risk Act in 2005 (northwest Atlantic population). The Estuary and the Gulf of St. Lawrence are summer feeding grounds for blue whales and other marine mammals. Blue whales eat only euphausiids (krill) and require dense concentrations of prey to meet their energy requirements, which makes them particularly vulnerable to changes in prey availability. In the LSLE, many species from secondary producers (hyperiid amphipods, other macrozooplankton) to top predators (fish, birds, and marine mammals) consumed euphausiids. Consequently, krill predators were found at all consumer trophic levels. However, our results showed that only about 35% of the estimated euphausiid production was consumed by all predator species combined. Euphausiid did not seem to be a restricted resource in the LSLE ecosystem, at least during the study period. The blue whale did not appear to have to compete for krill in the LSLE.

  5. Electrogenic sulfur oxidation in a northern saltmarsh (St. Lawrence Estuary, Canada).

    PubMed

    Rao, Alexandra; Risgaard-Petersen, Nils; Neumeier, Urs

    2016-06-01

    Measurements of porewater O2, pH, and H2S microprofiles in intact sediment cores collected in a northern saltmarsh in the St. Lawrence Estuary (Quebec, Canada) revealed the occurrence of electrogenic sulfur oxidation (e-SOx) by filamentous "cable" bacteria in submerged marsh pond sediments in the high marsh. In summer, the geochemical fingerprint of e-SOx was apparent in intact cores, while in fall, cable bacteria were detected by fluorescence in situ hybridization and the characteristic geochemical signature of e-SOx was observed only upon prolonged incubation. In exposed, unvegetated creek bank sediments sampled in the low marsh in summer, cable bacteria developed only in repacked cores of sieved (500 μm), homogenized sediments. These results suggest that e-SOx is suppressed by the activity of macrofauna in exposed, unvegetated marsh sediments. A reduced abundance of benthic invertebrates may promote e-SOx development in marsh ponds, which are dominant features of subarctic saltmarshes as in the St. Lawrence Estuary. PMID:27104296

  6. Immunotoxicity in plaice exposed to marine sediments in Baie des Anglais on the St. Lawrence Estuary

    SciTech Connect

    Lacroix, A.; Nagler, J.; Lee, K.; Lebeuf, M.; Cyr, D.; Fournier, M.

    1995-12-31

    The sediments of Baie des Anglais on the St. Lawrence Estuary have a history of environmental contamination. The purpose of the present study was to determine whether or not the immune system of American Plaice (Hippoglossoides Platessoides) could be affected following in-situ exposure at three different sites in and near Baie des Anglais. These sites vary with their proximity to local industry, Sites 1 and 2 (within the bay) being the closest and Site 3 (outside the bay) the furthest away. Fishes placed in cages at each site for three weeks, displayed head kidney cell immune responses (i.e., phagocytosis) modifications indicating that Site 1 was most immunotoxic and site 3 the least. Sediment chemical analysis show a gradient in contaminant concentrations with the highest levels recorded at Site 1, about 10-fold less at Site 2 and 100-fold less at Site 3. Organics predominated (PAHs, PCBs, PCDFs) with heavy metal concentrations low and representative of background levels for the St. Lawrence Estuary. The results obtained indicate that contaminants present in the sediments are bioavailable to fish and significantly affect their immune system.

  7. Hypoxia in the bottom water of the St. Lawrence Estuary: Is this ecosystem on borrowed time?

    NASA Astrophysics Data System (ADS)

    Lefort, S.; Gratton, Y.; Mucci, A.; Dadou, I.; Gilbert, D.

    2012-04-01

    When the rate of oxygen consumption in water exceeds the rate of supply, the oxygen concentration decreases and may reach levels that threaten the survival of many aquatic organisms. Waters with such low oxygen levels are termed severely hypoxic ([O2] < 62.5 µmol L-1). In 2011, the World Resources Institute identified 479 hypoxic coastal zones around the world, including fjords, estuaries, bays, shelves, as well as enclosed and semi-enclosed seas. These hypoxic environments are mainly found in coastal areas as a result of industrial and agricultural fertilizer discharge (i.e. eutrophication), and they develop during summer when the water column is strongly stratified; but hypoxia may also occur naturally and persist year-round. Historical records reveal that the dissolved oxygen concentration has progressively decreased in the bottom water of the Lower St. Lawrence Estuary (LSLE) during the last century and reached the severe hypoxic threshold in the 1980s where it has hovered ever since. The development of severe hypoxia in the LSLE has been mostly attributed to a gradual change in the properties (e.g. higher temperature, lower dissolved oxygen concentration) of the bottom water that enters the Laurentian Channel (Gulf of St. Lawrence, Eastern Canada). In addition, evidence of eutrophication has been reported in the LSLE, possibly increasing the oxygen demand in the water column and sediment. Increased respiration rates in the bottom water, in response to warming (from 3.3 to 5°C), has also been proposed to explain the increased depletion of oxygen in the Gulf. Nevertheless, whether hypoxia in the bottom water of the Laurentian Channel results from anthropogenic or natural forcings or both remain unclear. This presentation will examine the processes that govern the spatial distribution of dissolved oxygen in the water column and identify the causes that led to the development of large-scale hypoxia in the bottom waters of the LSLE. A laterally integrated advection-diffusion two-dimensional model was implemented to simulate the spatial distribution of dissolved oxygen and the development of hypoxic conditions in the deep waters of the Laurentian Channel (Estuary and Gulf of St. Lawrence). Our simulations reveal that the horizontal distribution of dissolved oxygen in the bottom waters of the Laurentian Channel is determined by a combination of physical and biogeochemical processes, whereas its vertical distribution is governed by the deep water circulation. This result strongly suggests that the physics of the system and the source water properties are mostly responsible for the oxygen depletion and its distribution pattern in the deep water column.

  8. Geomorphological characteristics and variability of Holocene mass-transport complexes, St. Lawrence River Estuary, Canada

    NASA Astrophysics Data System (ADS)

    Pinet, Nicolas; Brake, Virginia; Campbell, Calvin; Duchesne, Mathieu J.

    2015-01-01

    Recently acquired multibeam bathymetry data are used to investigate seafloor instability features along a 310 km-long segment of the St. Lawrence River Estuary. The analysis of this dataset indicates that submarine slides occur over a much larger area than previously recognized and that Holocene sediments are reworked by mass-transport along significant portions of both the northwest and southeast margins of the Laurentian Channel. In the surveyed area, 96 individual mass-transport complexes (MTCs) were identified representing 13% of the seabed. MTCs vary in area from less than 1 km2 to more than 40 km2 and exhibit various geomorphological signatures. Qualitative observation reveals an apparent disparity between MTCs that remain coherent and those that disintegrate during downslope transport evolving into a blocky morphological signature. For all MTCs, morphological parameters have been measured (area, length, and height) or calculated (slope and roughness). This quantitative analysis provides a unique opportunity to study these parameters in a statistically significant and homogeneous dataset located in a relatively small area that experienced a similar Quaternary history. In many cases, mass transport events appear to initiate in the vicinity of steep bedrock walls located along some segments of the estuary. The timing of mass-transport events was not constrained during this study. However, the fact that the region hosts the Charlevoix seismic zone, the most tectonically active area in eastern Canada, strongly suggests that earthquakes acted as a trigger for submarine landsliding.

  9. Organic contaminants and retinoids in Atlantic tomcod from two estuaries in the Gulf of St. Lawrence

    SciTech Connect

    Fairchild, W.L.; Arsenault, J.T.; Muir, D.C.G.; Brown, S.B.

    1994-12-31

    Atlantic tomcod (Microgadus tomcod) were collected in November 1993 from Miramichi Bay and Kouchibouguac Lagoon, on the Gulf of St. Lawrence coast of New Brunswick, Canada. The Miramichi has a long history of industrial and municipal activity, while Kouchibouguac Lagoon is within a National Park. Livers from male and female tomcod from each site were analyzed for organic contaminants. Sub-samples of the livers were analyzed for retinol (A{sub 1}), dehydroretinol (A{sub 2}), retinyl palmitate (A{sub 2}), and tocopherol (E). In addition, pooled livers from female smooth flounder (Pleuronectes putnami) from each site were analyzed for organic contaminants. Tomcod livers from the Miramichi had about 30x higher mean concentration of tri and tetrachloroveratrole (18 ng/g), and 6x higher concentration of pentachloroanisole (4.6 ng/g), than those from the Kouchibouguac. Total PCB congener concentration in liver was 1.5x higher in tomcod (116 ng/g), and 8x higher for smooth flounder (211 ng/g) from the Miramichi than the Kouchibouguac. Smooth flounder do not leave the estuaries, as tomcod do, during the summer. Little retinol or dehydroretinol was detected in tomcod livers from either site. Retinyl palmitate stores were lower in livers of fish from the Kouchibouguac, while tocopherol was detected but did not differ between sites.

  10. Anammox, denitrification and fixed-nitrogen removal in sediments from the Lower St. Lawrence Estuary

    NASA Astrophysics Data System (ADS)

    Crowe, S. A.; Canfield, D. E.; Mucci, A.; Sundby, B.; Maranger, R.

    2012-11-01

    Incubations of intact sediment cores and sediment slurries reveal that anammox is an important sink for fixed nitrogen in sediments from the Lower St. Lawrence Estuary (LSLE), where it occurs at a rate of 5.5 ± 1.7 µmol N m-2 h-1. Canonical denitrification occurs at a rate of 11.3 ± 1.1 µmol N m-2 h-1, and anammox is thus responsible for up to 33% of the total N2 production. Both anammox and denitrification are mostly (> 95%) fueled by nitrate and nitrite produced in situ through benthic nitrification. Nitrification accounts for > 15% of the benthic oxygen demand and may, therefore, contribute significantly to the development and maintenance of hypoxic conditions in the LSLE. The rate of dissimilatory nitrate reduction to ammonium is three orders of magnitude lower than denitrification and anammox, and it is insignificant to N-cycling. NH4+ oxidation by sedimentary Fe(III) and Mn(III/IV) in slurry incubations with N isotope labels did not occur at measurable rates; moreover, we found no evidence for NH4+ oxidation by added Mn(III)-pyrophosphate.

  11. Seasonal variability of denitrification efficiency in northern salt marshes: an example from the St. Lawrence Estuary.

    PubMed

    Poulin, Patrick; Pelletier, Emilien; Saint-Louis, Richard

    2007-06-01

    In coastal ecosystems, denitrification is a key process in removing excess dissolved nitrogen oxides and participating in the control of eutrophication process. Little is known about the role of salt marshes on nitrogen budgets in cold weather coastal areas. Although coastal salt marshes are important sites for organic matter degradation and nutrient regeneration, bacterial-mediated nitrogen cycling processes, such as denitrification, remain unknown in northern and sub-arctic regions, especially under winter conditions. Using labelled nitrogen (15N), denitrification rates were measured in an eastern Canadian salt marsh in August, October and December 2005. Freshly sampled undisturbed sediment cores were incubated over 8h and maintained at their sampling temperatures to evaluate the influence of low temperatures on the denitrification rate. From 2 to 12 degrees C, average denitrification rate and dissolved oxygen consumption increased from 9.6 to 25.5 micromol N2 m-2 h-1 and from 1.3 to 1.8 mmol O2 m-2 h-1, respectively, with no statistical dependence of temperature (p>0.05). Nitrification has been identified as the major nitrate source for denitrification, supplying more than 80% of the nitrate demand. Because no more than 31% of the nitrate removed by sediment is estimated to be denitrified, the presence of a major nitrate sink in sediment is suspected. Among possible nitrate consumption mechanisms, dissimilatory reduction of nitrate to ammonium, metal and organic matter oxidation processes are discussed. Providing the first measurements of denitrification rate in a St. Lawrence Estuary salt marsh, this study evidences the necessity of preserving and restoring marshes. They constitute an efficient geochemical filter against an excess of nitrate dispersion to coastal waters even under cold northern conditions. PMID:17276505

  12. Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments and biota of the Saguenay Fjord and the St. Lawrence Estuary

    SciTech Connect

    Brochu, C.; Moore, S.; Pelletier, E.

    1995-12-31

    Sediment samples and marine organisms were collected in the Saguenay Fjord and at two selected sites of the St. Lawrence Estuary in 1991. Total PCDDs and total PCDFs ranged from 22 to 352 ng kg{sup {minus}1} and 29 to 188 ng kg{sup {minus}1}, respectively in Saguenay sediments, while total PCDFs reached, 287 ng kg{sup {minus}1} in Baie des Anglais, a small and deep bay of the St. Lawrence Estuary impacted by PCBs during the 1970s. All biological samples contained detectable amounts of chlorinated dibenzodioxins and dibenzofurans, apart from the North Atlantic cod (Gadus morhua). The highest concentrations (up to 59.7 ng kg{sup {minus}1} total PCDFs and 2.54 ng kg{sup {minus}1} 2,3,7,8T4CDD Equivalent (TCDD TEQ)) were observed in crab (Chionoecetes opilio) caught in Saguenay Fjord and in crab and whelk (Buccinwn undatwn) collected in Baie des Anglais. Nordic shrimp (Pandalus borealis) is less contaminated with a maximum total PCDDs and PCDFs concentration of 14.0 ng kg{sup {minus}1} and TCDD TEQ never exceeding 0.7 ng kg{sup {minus}1}. Greenland halibut (Reinhardtius hippoglossoides) caught in the Saguenay Fjord contained only 2,3,7,8 substituted congeners in their tissues leading to a low average TCDD TEQ of 1.66 ng kg{sup {minus}1}. Based upon this first series of results, benthic organisms and fish from the Saguenay Fjord and the north shore of the St. Lawrence Estuary are exposed to low levels of PCDDs and PCDFs, and carry tissue concentrations well below international guidelines for fisheries products.

  13. Immune competence of rats fed with beluga whale blubber from the contaminated St. Lawrence estuary

    SciTech Connect

    Brousseau, P.; Lapierre, P.; Guise, S. De; Beland, P.; Martineau, D.; Fournier, M.

    1995-12-31

    Over the last decades, high concentrations of environmental contaminants such as PCBs have been measured in the tissues of many species of marine mammals from different parts of the world. Even though many deleterious effects of these compounds have been reported in laboratory animals, the overall risk associated with these contaminants in wild animals is still not clearly understood. However, necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria. Moreover, 37% of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. Indeed, both observations suggest immunosuppression. The aim of the study was to determine if contaminants present in fat tissues of belugas might provoke deleterious effect to their immune system if, under some circumstances, they are released into the circulation. To assess their immunotoxic potential, rats were fed for two months on a diet in which the lipids originated from the blubber of either highly polluted St. Lawrence belugas or relatively uncontaminated arctic belugas. Then, multiple immune responses were monitored. Those include phagocytosis, plaque forming cells, oxidative burst, natural killer cells, immunophenotyping and mitogenic assay. The results obtained show that only the humoral response of rats was impaired by the treatment. By combining all this information, the authors propose possible mechanisms of action to explain potential long-term consequences of environmental pollution.

  14. Polycyclic aromatic compounds in cod (Gadus morhua) from the Northwest Atlantic and St. Lawrence Estuary.

    PubMed

    Hellou, J; Upshall, C; Payne, J F; Hodson, P V

    1994-05-01

    There is limited information available on levels of polycyclic aromatic hydrocarbons (PAH) in major fish populations including populations from the Northwest Atlantic. The cod (Gadus morhua) stocks off eastern Canada form the basis of one of the world's most important fisheries. Muscle tissues of cod collected from Northwest Atlantic Fisheries Organisation (NAFO) management Divisions 2J, 3K and 3Ps off Newfoundland and Labrador, as well as three contaminated sites in the Gulf of St. Lawrence were analyzed for total polycyclic aromatic (PAC) by fluorimetry. Concentrations were determined in terms of crude oil and chrysene equivalents in line with recommendations of the International Oceanographic Commission. Overall, relatively low concentrations of PAC were found, the highest values generally being below 0.1 microgram/g (dry weight) in terms of chrysene equivalents. Similarly, only trace levels of a few PAH were detected in composite samples analyzed by gas chromatography-mass spectrometry (GC-MS). It is of interest that the highest levels of PAC were found in fish from NAFO Division 3K, while concentrations in fish from the two contiguous zones, 2J and 3Ps, as well as the Gulf of St. Lawrence, were similar. Division 3K is a major fishing zone and it is important to determine if trawler fleets are important sources of hydrocarbons derived from fossil fuels, in this and similar fishing areas of the world's oceans. PMID:8016631

  15. PCBs and OCPs in male harbour, grey, harp and hooded seals from the Estuary and Gulf of St Lawrence, Canada.

    PubMed

    Hobbs, Karen E; Lebeuf, Michel; Hammill, Mike O

    2002-09-16

    Blubber samples from adult male harbour seals (Phoca vitulina) from the St Lawrence Estuary, and from grey (Halichoerus grypus), harp (Phoca groenlandica) and hooded (Cystophora cristata) seals from the Gulf of St Lawrence, were analysed for polychlorinated biphenyls (PCB) and organochlorinated pesticides (OCP). All seals were between 5 and 19 years of age, and mean ages were not statistically different among the seal species. Mean concentrations of sigmaPCB and mirex were significantly higher in harbour seals, while sigmaDDT concentrations were significantly higher in hooded seals than in the other species examined. Harbour and hooded seals had similar concentrations of sigmaCHLOR, which were higher than in grey and harp seals. SigmaHCH concentrations were significantly higher in harp seals than in harbour and hooded seals and they were significantly higher in harbour and grey seals than in hooded seals. Harp and grey seals had similar levels of HCB, which were significantly higher than in either hooded or harbour seals. Patterns of PCB congeners and individual OCPs varied considerably between the four species. In PCA plots harbour, harp and hooded seals were well separated from each other, while grey seals were separated from the other species by a smaller degree. Between species variations may be explained by their dissimilar migratory patterns, habitat use and proximity to sources of industrial and agricultural pollution, their dietary regime (trophic level and individual prey items) as well as possible variations in the seals' abilities to eliminate these compounds. PMID:12398323

  16. Stable isotope evidence for glacial lake drainage through the St. Lawrence Estuary, eastern Canada, ~13.1-12.9 ka

    USGS Publications Warehouse

    Cronin, T. M.; Rayburn, J.A.; Guilbault, J.-P.; Thunell, R.; Franzi, D.A.

    2012-01-01

    Postglacial varved and rhythmically-laminated clays deposited during the transition from glacial Lake Vermont (LV) to the Champlain Sea (CS) record hydrological changes in the Champlain-St. Lawrence Valley (CSLV) at the onset of the Younger Dryas ∼13.1–12.9 ka linked to glacial lake drainage events. Oxygen isotope (δ18O) records of three species of benthic foraminifera (Cassidulina reniforme, Haynesina orbiculare, Islandiella helenae) from six sediment cores and the freshwater ostracode Candona from one core were studied. Results show six large isotope excursions (∼0.5 to >2‰) in C. reniforme δ18O values, five excursions in H. orbiculare (<0.5 to ∼1.8‰), and five smaller changes in I. helenae (<0.5‰). δ18O values in Candona show a 1.5–2‰ increase in the same interval. These isotopic excursions in co-occurring marine and freshwater species in varve-like sediments indicate complex hydrological changes in the earliest Champlain Sea, including brief (sub-annual) periods of complete freshening. One hypothesis to explain these results is that multiple abrupt freshwater influx events caused surface-to-bottom freshening of the Champlain Sea over days to weeks. The most likely source of freshwater would have been drainage of the Morehead Phase of glacial Lake Agassiz, perhaps in a series of floods, ultimately draining out the St. Lawrence Estuary.

  17. Tris (4-chlorophenyl) methane and tris (4-chlorophenyl) methanol in marine mammals from the Estuary and Gulf of St. Lawrence.

    PubMed

    Lebeuf, M; Bernt, K E; Trottier, S; Noël, M; Hammill, M O; Measures, L

    2001-01-01

    Levels of tris (4-chlorophenyl) methanol (TCPM) and its presumed precursor tris (4-chlorophenyl) methane (TCPMe) are reported in marine mammals from the Estuary and Gulf of St. Lawrence, Canada. These compounds were measured in blubber samples of seals and whales using ion trap mass spectrometry (MS/MS) detection. Detectable concentrations of both TCPM and TCPMe were observed in all of the samples analysed. Concentrations of these compounds varied with species ranging from 1.7 to 153 and from 1.3 to 50.6 ng/g lipid wt. for TCPM and TCPMe, respectively. TCPM was from 1.3 to 10 times more concentrated than TCPMe. The highest levels of both TCPM and TCPMe were observed in adult male beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, while adult female beluga whales from the same area showed levels similar to those in the seals examined. Among the four seal species investigated, TCPM and TCPMe levels were the highest in grey (Halichoerus grypus) and hooded (Cystophora cristata) seals, and lowest in harp seals (Phoca groenlandica). Intermediate levels were found in harbour seals (Phoca vitulina); however, their concentrations might be underestimated considering the younger mean age of these animals. Ratios of both 4,4'-DDE/sigma DDT and TCPM/sigma TCP were very similar between animals from the same species. Strong correlations between sigma TCP and sigma DDT were also observed for each species of mammals, most likely indicating that both sigma TCP and sigma DDT are bioaccumulated in marine mammals. The relationships between sigma DDT and sigma TCP also demonstrate that sigma TCP are less bioaccumulated than sigma DDT by the marine mammal species examined. PMID:11202713

  18. Benthic fluxes of dissolved organic nitrogen in the Lower St. Lawrence Estuary and implications for selective organic matter degradation

    NASA Astrophysics Data System (ADS)

    Alkhatib, M.; del Giorgio, P. A.; Gelinas, Y.; Lehmann, M. F.

    2013-05-01

    The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment pore waters was determined at nine locations along the St. Lawrence Estuary and in the Gulf of St. Lawrence. The study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, as well as benthic respiration rates. Based on pore water profiles we estimated the benthic diffusive fluxes of DON and DOC. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m-2 d-1). DON fluxes were positively correlated with sedimentary POM reactivity and sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30% to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange. This result is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. The ratio of the DON to nitrate flux increased from 0.6 in the Lower Estuary to 1.5 in the Gulf. In contrast to DON, DOC fluxes did not show any significant spatial variation along the Laurentian Channel (LC) between the Estuary and the Gulf (2100 ± 100μmol m-2 d-1), suggesting that production and consumption of labile DOC components proceed at similar rates, irrespective of the overall benthic characteristics and the reactivity of POM. As a consequence, the molar C/N ratio of dissolved organic matter (DOM) in pore water and the overlying bottom water varied significantly along the transect, with lowest C/N in the Lower Estuary (5-6) and highest C/N (> 10) in the Gulf. We observed large differences between the C/N of pore water DOM with respect to POM, and the degree of the C- versus -N element partitioning seems to be linked to POM reactivity and/or redox conditions in the sediment pore waters. Our results thus highlight the variable effects selective OM degradation and preservation can have on bulk sedimentary C/N ratios, decoupling the primary source C/N signatures from those in sedimentary archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

  19. Habitat use and movements of postfledging American black ducks (Anas rubripes) in the St. Lawrence estuary, Quebec

    USGS Publications Warehouse

    Clugston, D.A.; Longcore, J.R.; McAuley, D.G.; Dupuis, P.

    1994-01-01

    We used radiotelemetry to determine habitat use and movements of 38 female juvenile American black ducks (Anas rubripes) on the north shore of the St. Lawrence estuary, Quebec, from 28 August to 15 November 1991. Ducks separated into three groups based on habitat use: inland, estuarine, and those using a mixture of habitats. Ducks using mixed habitats used the greatest variety of habitat types, flew the greatest distances and most often between night roosts and day foraging areas, and were unlikely to be shot. The mean distance flown between night-use and day-use areas for all ducks increased nearly 50% after the hunting season began (overall mean = 6104 m, range 1500 - 26384 m). Mean home range size was 27.6 t 6.5 (SE) km2. Ducks exhibited stronger fidelity to wetlands used at night than to those used during the day. Ducks that were shot spent a high percentage of their time on the estuary (90.1 t 7.4 %) and exhibited high fidelity to a day-use area before the hunting season (73 t 7.3 %).

  20. Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation

    NASA Astrophysics Data System (ADS)

    Alkhatib, M.; del Giorgio, P. A.; Gelinas, Y.; Lehmann, M. F.

    2013-11-01

    The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m-2 d-1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m-2 d-1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5-6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

  1. Late-Wisconsinan submarine moraines along the north shore of the Estuary and Gulf of St. Lawrence (Eastern Canada)

    NASA Astrophysics Data System (ADS)

    Lajeunesse, Patrick; St-Onge, Guillaume

    2013-04-01

    A series of ice-contact submarine fans and morainal banks along the Québec North-Shore of the Estuary and Gulf of St. Lawrence (Eastern Canada), between the Manicouagan River delta and the Mingan Islands, have been revealed with great detail by recent multibeam echosounder and high-resolution subbottom profiler surveys. These grounding-line landforms are observed between 65 and 190 m water depths and were constructed as the marine-based margin of the Laurentide Ice Sheet (LIS) stabilized or readvanced. Radiocarbon ages obtained from shells sampled in sediment cores collected in glaciomarine deposits 6 km south of a grounding line in the Sept-Iles area indicate a stabilisation that took place around 11 000 14C yr BP (12.5 ka cal BP with a ΔR=120 ± 40 yr). In the Mingan Islands area, organic matter collected in distal deposits of an ice-contact fan is dated at 10 800 14C yr BP (11.6 ka cal BP). The position of the Sept-Iles and Mingan deposits, 20 km south of the ~9.7-9.5 14C kyr BP North-Shore Moraine, suggests that these ice marginal landforms were constructed during the Younger Dryas (YD) cold episode and that they might be the eastward submarine extent of the early YD St. Narcisse morainic system. Superimposed till sheets and morainal banks observed within grounding line deposits indicate that this stability phase was interrupted by local readvances that were marked in some cases by ice streaming. Segments of this morainic system are also visible along the shoreline in some sectors, where they have been generally washed out of fine fragments by waves. Another series of ice-contact deposits and landforms of similar nature observed farther offshore and at greater depths (100-190 m) were formed during a previous phase of stabilisation of the LIS margin. This older morainic system was probably deposited immediately after the opening of the Estuary and Gulf of the St. Lawrence.

  2. Land use and nitrogen loading in seven estuaries along the southern Gulf of St. Lawrence, Canada

    NASA Astrophysics Data System (ADS)

    McIver, Reba; Milewski, Inka; Lotze, Heike K.

    2015-11-01

    Nitrogen loading from coastal watersheds is a principal factor associated with the decline in eelgrass bed health and cover in estuaries worldwide. We apply the Nitrogen Loading Model (NLM) framework developed in Waquoit Bay, Massachusetts to 7 estuaries in eastern New Brunswick. Using watershed-specific information on human population, wastewater production, atmospheric deposition, and land use in each watershed we estimate annual input of Total Dissolved Nitrogen (TDN) from point and non-point sources. We also estimate flushing time of each estuary using available hydrodynamic and bathymetric data incorporated in a tidal prism model. Finally, we validate the NLM results by testing the link between estimated nitrogen loading, flushing time and nitrogen signals in eelgrass tissue including nitrogen content and stable isotopes. Overall, total nitrogen load (kg TDN yr-1) was strongly dependent on watershed and estuary size, while loading rate per unit watershed area (yield) was linked to watershed population density. Atmospheric deposition was the largest contributor of nitrogen to all estuaries except one, where seafood processing effluent was the greatest source. Stable isotope analysis of eelgrass tissue reflected this distinction, with high δ15N values of 8-10‰ related to high wastewater loading, compared to 2-6.5‰ in the other estuaries that receive proportionally more atmospheric deposition. Tissue nitrogen content was positively related to nitrogen yields and loading rate per volume of estuary, highlighting the influence of variable watershed:estuary size ratio. Multiple regression analysis identified a significant interaction between nitrogen yield and flushing time on eelgrass tissue nitrogen content and isotopes, pointing to the mitigating effect an estuary's quick flushing time can have on the expression of nitrogen enrichment in primary producers. The compilation of new information on nitrogen loading to east Canadian estuaries is a novel contribution from a region where human influences are still at a relatively low level, and hence will add to existing information from cold temperate, mainly forested watershed-estuary environments.

  3. Modern Gas Vents in the St. Lawrence Estuary (Eastern Canada); Linking Palaeozoic Rocks, Quaternary Sediments and the Marine Environment.

    NASA Astrophysics Data System (ADS)

    Duchesne, M. J.; Pinet, N.; Bolduc, A.; Lavoie, D.; Campbell, D. C.

    2007-12-01

    Since 2003, the seafloor and the subsurface of the St. Lawrence Estuary (eastern Canada) were surveyed with various geophysical tools such as high and very-high resolution seismic reflection systems, sidescan sonar and multibeam echo sounder; moreover several cores were collected. The most striking features on the multibeam bathymetric imagery are numerous pockmarks (n>750) ranging in diameter from tens to hundreds of meters. The use of multi-resolution geophysical systems allowed the documenting of their fractal nature as micro and macro seeps are observed. Pockmarks are isolated, associated with submarine landslides, linearly distributed or included in cluster features. Sidescan sonar coverage confirms that some vents are active whereas backscatter images show several highly- reflective pockmarks. Carbonate crusts were sampled in some of these highly-reflective features whereas in other pockmarks similar crusts, located at various depths in the sedimentary column, indicate possible intermittent chemosynthetic microbial activity through recent times. Seismic sections permitted to image gas chimneys beneath the pockmarks that are rooted into the bedrock and gas-related amplitude anomalies within the Quaternary succession. In addition several seismic anomalies are found over either bedrock highs or slightly- dipping features imaged near the top of the bedrock. The pockmarks distribution correlates with both the bedrock geology and the thickness of the Quaternary deposits. Pockmarks are preferentially found above the Paleozoic autochtonous domain (St. Lawrence platform) and located where the Quaternary sediment cover is the thinnest (<200 m) although seismic anomalies attributed to the presence of gas, are observed over the entire basin including where the Quaternary succession is the thickest (>420 m). The results of the study suggest that gas release in the marine environment is likely of thermogenic origin and controlled by one or several of the following parameters: 1) the occurrence of a leaking seal layer in some parts of the basin, 2) the lithostatic pressure induced by the Quaternary succession or 3) the physical properties of the underlying breached Paleozoic reservoirs.

  4. Hypoxia in the St. Lawrence Estuary: How a Coding Error Led to the Belief that “Physics Controls Spatial Patterns”

    PubMed Central

    2015-01-01

    Two fundamental sign errors were found in a computer code used for studying the oxygen minimum zone (OMZ) and hypoxia in the Estuary and Gulf of St. Lawrence. These errors invalidate the conclusions drawn from the model, and call into question a proposed mechanism for generating OMZ that challenges classical understanding. The study in question is being cited frequently, leading the discipline in the wrong direction. PMID:26397371

  5. Chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary.

    PubMed Central

    Gagnon, Fabien; Tremblay, Thierry; Rouette, Justine; Cartier, Jacques-François

    2004-01-01

    Shellfish have the capacity to accumulate chemical contaminants found in their biotope and therefore present a potential risk for consumers. This study was conducted to assess the chemical risks associated with consumption of shellfish harvested on the north shore of the St. Lawrence River's lower estuary. A survey was carried out on 162 recreational harvesters, and shellfish were sampled for chemical contaminant analysis. We quantified 10 metals, 22 polycyclic aromatic hydrocarbons (PAHs), 14 polychlorinated biphenyls (PCBs), and 10 chlorinated pesticides. We subsequently evaluated cancer and noncancer risks for four consumption scenarios based on our survey results and published results. Soft-shell clams (Mya arenaria) were by far the most consumed shellfish species. Of the 56 selected contaminants, 36 were detected in the 23 homogenates of soft-shell clam meat. None of the contaminants found in the soft-shell clams were associated with intakes that exceed the main exposure limit recommendations proposed to prevent noncancer effects. However, several limits must be considered before drawing conclusions about the relative safety of shellfish consumption regarding this end point. Furthermore, inorganic arsenic and PCBs were present in sufficient concentrations to lead to cancer risks exceeding the level often considered acceptable for environmental exposure (1 x 10 (-4) to 1 x 10(-6)) in each of the four scenarios, even for the lowest observed scenario of 15 meals of soft-shell clams per year. PMID:15175177

  6. Passive remote sensing of chlorophyll in the lower St. Lawrence Estuary: Spectral optimization of detection algorithms and SeaWiFs application

    NASA Astrophysics Data System (ADS)

    Jacques, Andre

    2002-01-01

    This work is one more step toward passive remote sensing as a way to estimate the water chlorophyll content in the St-Lawrence Estuary. In July 1993, during the LIDAR-93 oceanographic cruise, optical and biochemical data were collected to identify the best remote sensing algorithms for chlorophyll in this area. Many algorithms were tested on radiometric data acquired with two portable spectroradiometers aboard ship and a CASI imaging spectoradiometer during low altitude flights. A good consistency was obtained between both data types. An exhaustive search on the visible spectrum has allow to identify some simple and multiple band ratios as best algorithms. Among these simple band ratios, the best results were obtained with 540 and 580 nm bands. Some blue-red ratios (420 to 520 nm/660 to 700 nm) also gave good results. Estimates precision were about 40 to 50%. The best multiple band ratios allow estimations of water chlorophyll content with an accuracy of +/-30%. The estimates are better in the central and western region of the Estuary. However, all algorithms overestimate chlorophyll content in the eastern part of the Estuary. It seems that these overestimates are due to the vertical distribution of Chl in the water column. With simulated SeaWiFs bands, the estimates accuracy is about 50% for simple band ratios and 40% for multiple band ratios. Poorer accuracy obtained with SeaWiFs bands seems due most to the lack of one more band in the red part of the spectrum than to the spectral resolution. Simulations with CAM5S software, on the impact of errors on atmospheric aerosol optical thickness estimations, show that 490/670 nm would be the best band ratio to use with SeaWiFs sensor for the St-Lawrence Lower Estuary. An accuracy of +/-0,02 on aerosol optical depth would be enough to have a global accuracy of about 60% on water chlorophyll content estimates in the Lower St-Lawrence Estuary.

  7. Spatial distribution and viability of Alexandrium tamarense resting cysts in surface sediments from the St. Lawrence Estuary, Eastern Canada

    NASA Astrophysics Data System (ADS)

    Gracia, Stéphanie; Roy, Suzanne; Starr, Michel

    2013-04-01

    The dinoflagellate Alexandrium tamarense Group 1 (as defined by Lilly et al., 2007) is responsible for recurrent outbreaks of paralytic shellfish poisoning (PSP) in the St. Lawrence Estuary (SLE), Eastern Canada. In August 2008, a major bloom of A. tamarense developed in the SLE and caused major mortality of fish, seabirds and marine mammals notably in the vicinity of a marine park. Eleven months later, surface (0-5 cm) and deeper (5-10 cm) sediments were sampled to determine resting cysts concentrations, locate prospective cyst seedbeds and examine if these had changed following this major bloom. This information is thought to be important to understand inter-annual patterns in algal toxicity, cyst abundance being a good predictor of subsequent bloom magnitude in some regions. Surface cyst distribution was heterogeneous and it confirmed the location of the cyst seedbed previously reported on the north shore near the Manicouagan/aux-Outardes Rivers (>500 cysts cm-3). A zone of cyst accumulation was also observed on the south shore of the SLE (maximum of 1200 cysts cm-3), with higher concentrations relative to previous cyst mapping in the 1980s. A mismatch was observed between the zones with high surface cyst concentrations and those where the highest PSP toxins were detected (used as a proxy for vegetative cells in the water column). Cyst concentrations were negatively correlated with PSP levels from the same sites, suggesting that cysts were formed and deposited away from the major sites of toxicity. Deposition likely took place near the end of the bloom, once it had reached the eastern boundary of the SLE. PSP toxicity was worse near the peak of the bloom, which occurred westward of this region. This highlights the dynamic behaviour of local blooms, influenced by the estuarine and mesoscale circulation. Interestingly, the major bloom of August 2008 was not followed by particularly large cyst deposition or by any major bloom in 2009 in this region. Cyst viability was also examined, using Sytox Green, and found to be highest (nearly 100%) in the sites where cyst concentrations were maximum. Our results call for further investigation of the cyst mapping hypothesis in the St. Lawrence, where the local circulation seems to have an overriding influence on cyst deposition patterns.

  8. A twenty-one year temporal trend of persistent organic pollutants in St. Lawrence Estuary beluga, Canada.

    PubMed

    Lebeuf, Michel; Measures, Lena; Noël, Michelle; Raach, Meriem; Trottier, Steve

    2014-07-01

    Persistent organic pollutants (POPs) were measured in blubber from 144 stranded adult belugas (Delphinapterus leucas) found on the shores of the St. Lawrence Estuary (SLE) between 1987 and 2007. Temporal trends of POP concentrations (ln transformed) in beluga were described by three models, zero slope (ZS), linear (L) and two-segment piecewise (PW). Often two but sometimes all three models were equivalent in describing temporal trends based on Akaike's Information Criterion for small sample sizes. Over this 21-year time period, concentrations of most legacy POPs, including PCBs, DDTs and HCHs, exhibited relatively weak (≤11% per year) but significant decreasing trends in beluga. For PBDEs, temporal trends were best described by a PW model, characterizing a rapid increase until 1997-1998 followed by a slower increase for males and a steady-state for females. Potential cofactors such as blubber lipid content and carcass state of preservation did not show any significant temporal trends over the time period considered. Nitrogen stable isotope ratios (δ(15)N) in beluga liver, a proxy of trophic level, could not be associated to any effect on temporal trends of POP concentrations in beluga. Several POPs exhibited significant relationships with age of beluga and data were age-adjusted. Temporal trends of POP concentrations adjusted for age of beluga were reassessed but results were essentially identical as those obtained with the original POP data. Overall, POP temporal trends observed in SLE beluga are consistent with changes expected from regulations and restrictions in the use of these compounds in developed countries. PMID:24742546

  9. Cancer in wildlife, a case study: beluga from the St. Lawrence estuary, Québec, Canada.

    PubMed Central

    Martineau, Daniel; Lemberger, Karin; Dallaire, André; Labelle, Philippe; Lipscomb, Thomas P; Michel, Pascal; Mikaelian, Igor

    2002-01-01

    A population of approximately 650 beluga (Delphinapterus leucas) inhabits a short segment of the St. Lawrence estuary (SLE). Over 17 years (1983-1999), we have examined 129 (or 49%) of 263 SLE beluga carcasses reported stranded. The major primary causes of death were respiratory and gastrointestinal infections with metazoan parasites (22%), cancer (18%), and bacterial, viral, and protozoan infections (17%). We observed cancer in 27% of examined adult animals found dead, a percentage similar to that found in humans. The estimated annual rate (AR) of all cancer types (163/100,000 animals) is much higher than that reported for any other population of cetacean and is similar to that of humans and to that of hospitalized cats and cattle. The AR of cancer of the proximal intestine, a minimum figure of 63 per 100,000 animals, is much higher than that observed in domestic animals and humans, except in sheep in certain parts of the world, where environmental contaminants are believed to be involved in the etiology of this condition. SLE beluga and their environment are contaminated by polycyclic aromatic hydrocarbons (PAHs) produced by the local aluminum smelters. The human population living in proximity of the SLE beluga habitat is affected by rates of cancer higher than those found in people in the rest of Québec and Canada, and some of these cancers have been epidemiologically related to PAHs. Considered with the above observations, the exposure of SLE beluga to PAHs and their contamination by these compounds are consistent with the hypothesis that PAHs are involved in the etiology of cancer in these animals. PMID:11882480

  10. Immune functions in the Fisher rat fed beluga whale (Delphinapterus leucas) blubber from the contaminated St. Lawrence estuary

    SciTech Connect

    Lapierre, P.; Guise, S. De; Muir, D.C.G.; Norstrom, R.; Beland, P.; Fournier, M.

    1999-02-01

    In order to assess the immunotoxic potential of food naturally contaminated with PCBs and other organohalogens, Fisher rats were fed a diet in which the lipids originated from the blubber of either a highly polluted St. Lawrence beluga or a relatively uncontaminated Arctic beluga. After a period of 2 months, different immune functions were evaluated, including lymphoblastic transformation, natural killer cell activity, plaque-forming cells, phagocytosis, oxidative burst, and immunophenotyping. For all assays, rats fed at St. Lawrence beluga blubber diet or a mixture of Arctic and St. Lawrence beluga blubber diet were not different from control rats fed a diet containing Arctic beluga blubber. These results are inconsistent with the well-known immunosuppressive effects of organochlorines in numerous species and with the lesions suggestive of organochlorine-related immunosuppression that are observed in St. Lawrence belugas. The lack of observable immunotoxic effects in rats fed contaminated beluga blubber might be explained by antagonistic effects in the organohalogen mixture, by a response specific to the rat, by a strain-related lack of sensitivity to organochlorines, or by insufficient dose due to the shortness of the exposure period or the route of exposure.

  11. Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology, classification and recent sediment dynamics

    NASA Astrophysics Data System (ADS)

    Normandeau, Alexandre; Lajeunesse, Patrick; St-Onge, Guillaume

    2015-07-01

    Series of submarine canyons and channels observed in the Lower St. Lawrence Estuary (LSLE) provide an opportunity to analyze in great detail the morphology, spatial distribution and modern activity of such systems in a relatively shallow (≤ 300 m) semi-enclosed basin. Based on their geomorphology and physical settings, the canyons and channels were classified into four categories according to their feeding sources (ancient or recent): glacially-fed, river-fed, longshore drift-fed and sediment-starved systems. Their activity was interpreted based on geomorphological characteristics such as the presence of bedforms related to gravity flows, backscatter intensity, axial incision and the presence of rapidly deposited layers in surficial sediments. River-fed deltas were interpreted as inactive, mainly because suspended sediment concentrations at river mouths are low, preventing the generation of hyperpycnal currents or delta-lip failures related to high sediment supply. Longshore drift-fed canyons, present where the coastal shelf narrows, were found to be episodically active probably due to earthquakes or extreme storm events. Unlike other longshore drift-fed canyons observed elsewhere in the world, they are active infrequently because of the modern low rates of sediment supply to their heads. The most active canyons are the sediment-starved type and were observed near Pointe-des-Monts. Their activity is probably due to slope failures and to the presence of strong hydrodynamic processes. Therefore, sediment supply is not the main mechanism responsible for modern canyon and channel activity in the LSLE. However, sediment supply has been an important factor during the formation of the submarine channels and canyons. Their quasi-exclusive occurrence on the Québec North Shore is attributed to its larger watershed and important sedimentary delivery during deglaciation. The Québec North Shore watershed is 20 times greater than the Québec South Shore watershed, which favored the transport of greater volumes of sediment during the early-Holocene. Moreover, the slope proximity to the shore led to the formation of longshore-drift fed systems on the North Shore when sediment supplied to rivers were transferred on a narrow shelf.

  12. Levels of C{sub 10}-C{sub 13} polychloro-n-alkanes in marine mammals from the Arctic and the St. Lawrence River estuary

    SciTech Connect

    Tomy, G.T.; Muir, D.C.G.; Stern, G.A.; Westmore, J.B.

    2000-05-01

    Marine mammals from various regions of the Arctic and the St. Lawrence River estuary were examined for the first time for levels of C{sub 10}--C{sub 13} polychloro-n-alkanes (sPCAs). Respective mean total sPCA concentrations in the blubber of beluga whales (Delphinapterus leucas) from Saqqaq and Nuussuaq, western Greenland, were 0.23 {+-} 0.02 (n = 2) and 0.164 {+-} 0.06 {micro}g/g (n = 2), similar to that in beluga from the Mackenzie Delta in the western Canadian Arctic 0.21 {+-} 0.08 {micro}g/g (m = 3). sPCAs levels were higher in beluga blubber from the St. Lawrence River (0.37 to 1.4 {micro}g/g). Mean sPCA concentrations in the blubber samples from walruses (Odobenus rosmarus) (Thule, northwest Greenland) and ringed seal (Phoca hispida) (Eureka, southwest Ellesmere Island) were 0.43 {+-} 0.06 (n = 2) and 0.53 {+-} 0.2 {micro}g/g (n = 6), respectively. Relative to commercial sPCA formulations, samples from the Arctic marine mammals showed a predominance of the shorter chain length lower percent chlorinated PCA congeners, the more volatile components of industrial formulations. This observation is consistent with long-range atmospheric transport of sPCAs to this region. The profiles of the belugas from the St. Lawrence River estuary, however, had higher proportions of the less volatile sPCA congeners, implying that contamination to this region is probably from local sources.

  13. Temporal and spatial variability of tidal-fluvial dynamics in the St. Lawrence fluvial estuary: An application of nonstationary tidal harmonic analysis

    NASA Astrophysics Data System (ADS)

    Matte, Pascal; Secretan, Yves; Morin, Jean

    2014-09-01

    Predicting tides in upstream reaches of rivers is a challenge, because tides are highly nonlinear and nonstationary, and accurate short-time predictions of river flow are hard to obtain. In the St. Lawrence fluvial estuary, tide forecasts are produced using a one-dimensional model (ONE-D), forced downstream with harmonic constituents, and upstream with daily discharges using 30 day flow forecasts from Lake Ontario and the Ottawa River. Although this operational forecast system serves its purpose of predicting water levels, information about nonstationary tidal-fluvial processes that can be gained from it is limited, particularly the temporal changes in mean water level and tidal properties (i.e., constituent amplitudes and phases), which are function of river flow and ocean tidal range. In this paper, a harmonic model adapted to nonstationary tides, NS_TIDE, was applied to the St. Lawrence fluvial estuary, where the time-varying external forcing is directly built into the tidal basis functions. Model coefficients from 13 analysis stations were spatially interpolated to allow tide predictions at arbitrary locations as well as to provide insights into the spatiotemporal evolution of tides. Model hindcasts showed substantial improvements compared to classical harmonic analyses at upstream stations. The model was further validated by comparison with ONE-D predictions at a total of 32 stations. The slightly lower accuracy obtained with NS_TIDE is compensated by model simplicity, efficiency, and capacity to represent stage and tidal variations in a very compact way and thus represents a new means for understanding tidal rivers.

  14. Identification and Dating of a key Late Pleistocene Stratigraphic Unit in the St. Lawrence Estuary and Gulf (Eastern Canada): Implications for the 400-m Thick Quaternary Sequence at the Former Margin of the Laurentide Ice Sheet

    NASA Astrophysics Data System (ADS)

    St-Onge, G.; Lajeunesse, P.; Duchesne, M.; Gagné, H.

    2008-12-01

    A recently acquired 8-m long sediment core along with high-resolution seismic-reflection and sub-bottom profiler sections allowed the identification, characterization and dating of a widespread seismic unit extending from the head of the Laurentian Channel (Lower St. Lawrence Estuary) to Honguedo Strait (Gulf of St. Lawrence), Eastern Canada. This seismic unit (termed unit 2) is characterized by a series of parallel high- amplitude reflections with thicknesses ranging from 68 m near the head of the Laurentian Channel to <5 m in Honguedo Strait. This seismic unit is generally observed below a very thick unit of postglacial sediments that can reach >250 m in the St. Lawrence Estuary, leaving it very difficult to be reached by conventional coring operations. Here, we reveal how we were able to trace and core this seismic unit in an area where it lays closer to the seafloor near the southern wall of the Laurentian Channel in the Lower St. Lawrence Estuary. This seismic unit consists of two sedimentary facies: sandy mud including ice rafted debris (IRD) underlying faintly laminated to homogenous and plastic silty clays. Based on the sedimentary facies, we interpret the upper clays as ice-distal glaciomarine sediments and the lower sandier sediments as ice- proximal glaciomarine sediments. Seismic unit 2 is highly disturbed by iceberg scouring in the Gulf of St. Lawrence where it is found at shallower depths, indicating that it was deposited during deglaciation. The available AMS 14C dates obtained in the ice-proximal glaciomarine sediments indicate that the lower part of seismic unit 2 was deposited during local re-advances of the Laurentide Ice Sheet margin in the Goldthwait Sea that began at or before the Younger Dryas cold event (11 100 to 10 000 yr BP) and that seismic unit 2 can be used as a chronostratigraphic marker throughout the St. Lawrence Estuary and northwestern Gulf of St. Lawrence. Moreover, because the seismic character of the sediments below seismic unit 2 is not typical of ice-contact or sub-glacial sediments, they represent either a very thick sequence (with very high sediment accumulation rates) of slightly older deglacial sediments or pre-Wisconsinan sediments (i.e., Marine Isotopic Stages >4). Nonetheless, without further evidence, we cannot rule out either one of these alternatives, highlighting the potential of the St. Lawrence Estuary for the recovery of a very detailed sequence of possibly at least the last interglacial/glacial cycle.

  15. Cyclic steps in proglacial delta fronts: New insights from Upper Pleistocene-Holocene successions, St. Lawrence Estuary and Gulf, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Dietrich, Pierre; Ghienne, Jean-François; Normandeau, Alexandre; Lajeunesse, Patrick

    2015-04-01

    Proglacial delta fronts in both present-day systems and in the sedimentary record frequently include sand-sized, upstream-migrating bedforms. Although several studies have recently monitored their sediment dynamics, their formative processes are still matter to debate. Here we report on two Pleistocene-Holocene proglacial deltaic successions located on the North Shore of the St. Lawrence Estuary and Gulf, Québec, Canada. Owing to a well-constrained pattern of glacio-isostatic rebound, these now-emerged successions are characterized by accurate palaeo-bathymetric reconstructions. In our case study, we describe backstepping (upstream-migrating) cross strata lying on delta foresets at shallow bathymetries ranging from 10 m to deeper part, reaching in places 50 m. Cross strata, interpreted as being deposited by Froude-supercritical cyclic steps, are characterized by steep mean dips (up to 13°) and short-wavelength (10-20 m) undulations. They form backstepping assemblages of massive to faintly laminated sand bounded on either side by downslope-dipping erosive surfaces on which strata onlap and are truncated upslope and downslope respectively. Graded sand beds, sheared flamed mud layers, matrix- to clasts-supported pebbles or sand intraclasts occasionally occur. In a first case study located in the St. Lawrence Estuary (Portneuf), cyclic steps are borne by gently-sloped (2-3°) foresets deposits at depositional depth less than 50 m. Related sand includes graded beds, thin (5-10 mm) muddy interbeds and terrestrial organic debris. In a second delta located in the Gulf of St. Lawrence (Moisie River), backstepping, faintly laminated gravelly sand beds are directly overlain by pebbly topsets constituted by the subaqueous termination of a sandur. They are in addition either sharply truncated or are passing gradually downslope to regular, steep-sloped gilbert-like delta foresets. Scour infills with backsets are commonly associated with these strata that were deposited at very shallow bathymetries (10 m) as inferred from the stratigraphic architecture. These features suggest that river outflow directly derived from proglacial distributary channel(s) on the delta plain is responsible for the genesis of cyclic steps on delta foresets. The outflow maintained its inherited supercritical state without experiencing a hydraulic jump while entering the sea. This scenario is an alternative to depositional models linking cyclic steps generation and mass-wasting processes related to mouth bars oversteepening. We argue that either meltwater outburst flows issuing from a nearby ice-margin or spring low tide condition, or a combination of both, can produce adequate flow conditions, in terms of water and sediment discharge, for creating supercritical flow and related depositional structures in delta front settings.

  16. Investigation into the response of the auditory and acoustic communications systems in the Beluga whale (Delphinapterus leucas) of the St. Lawrence River Estuary to noise, using vocal classification

    NASA Astrophysics Data System (ADS)

    Scheifele, Peter Martin

    2003-06-01

    Noise pollution has only recently become recognized as a potential danger to marine mammals in general, and to the Beluga Whale (Delphinapterus leucas) in particular. These small gregarious Odontocetes make extensive use of sound for social communication and pod cohesion. The St. Lawrence River Estuary is habitat to a small, critically endangered population of about 700 Beluga whales who congregate in four different sites in its upper estuary. The population is believed to be threatened by the stress of high-intensity, low frequency noise. One way to determine whether noise is having an effect on an animal's auditory ability might be to observe a natural and repeatable response of the auditory and vocal systems to varying noise levels. This can be accomplished by observing changes in animal vocalizations in response to auditory feedback. A response such as this observed in humans and some animals is known as the Lombard Vocal Response, which represents a reaction of the auditory system directly manifested by changes in vocalization level. In this research this population of Beluga Whales was tested to determine whether a vocalization-as-a-function-of-noise phenomenon existed by using Hidden Markhov "classified" vocalizations as targets for acoustical analyses. Correlation and regression analyses indicated that the phenomenon does exist and results of a human subjects experiment along with results from other animal species known to exhibit the response strongly implicate the Lombard Vocal Response in the Beluga.

  17. Congener-specific analysis of the accumulation of polychlorinated biphenyls (PCBs) by aquatic organisms in the maximum turbidity zone of the St. Lawrence estuary, Québec, Canada.

    PubMed

    Gagnon, M M; Dodson, J J; Comba, M E; Kaiser, K L

    1990-11-01

    The polychlorinated biphenyl (PCB) contamination of the biota of the St. Lawrence estuary maximum turbidity zone (MTZ) was investigated. The species analyzed consist of zooplankton (mostly Neomysis americana), larval smelt (Osmerus mordax), juvenile smelt, juvenile tomcod (Microgadus tomcod) and adult smelt, tomcod and capelin (Mallotus villosus). A significant increase in total PCB contamination from zooplankton to all fish developmental stages indicates that the St. Lawrence MTZ is a site of significant PCB contamination. The total PCB contamination of adult smelt and tomcod sampled in the St. Lawrence MTZ was greater than the limit of 0.1 ppm set by the International Joint Commission for the protection of predators. For zooplankton, tomcod and capelin, significant correlations were found between lipid content and PCB contamination. The congener-specific analyses showed that the bioconcentration factor of the individual congeners varied with the species involved and with the molecular structure of the congener. It was found that the chlorine atoms in positions 2, 4 and 5 on at least one phenyl ring of the PCB molecule was a dominant factor causing accumulation of PCBs in aquatic organisms. The pattern of PCB congeners found in beluga (Delphinapterus leucas) whale tissues is similar to the PCB pattern found in the St. Lawrence estuary MTZ biota. PMID:2128134

  18. Pathologic Findings and Trends in Mortality in the Beluga (Delphinapterus leucas) Population of the St Lawrence Estuary, Quebec, Canada, From 1983 to 2012.

    PubMed

    Lair, S; Measures, L N; Martineau, D

    2016-01-01

    An isolated population of beluga (Delphinapterus leucas) inhabits the St Lawrence Estuary, Quebec, Canada. This population has failed to recover despite the prohibition of hunting >30 years ago, suggesting the presence of other limiting factors. The authors summarize the reported causes of death and propose risk factors to explain the lack of recovery of this population. From 1983 to 2012, a total of 472 beluga were found stranded. Complete necropsies were carried out on 222 beluga, including 178 adults, 25 juveniles, and 19 newborn calves. Infectious diseases, the most prevalent cause of mortality in this population, accounted for the death of one-third of all beluga (32%). Verminous pneumonia was the cause of mortality of 13 juvenile beluga (52% of juvenile beluga). A total of 39 malignant neoplasms, diagnosed in 35 beluga, caused the death of 31 beluga (20% of beluga >19 years old). Median age at diagnosis of cancer was 48 years (range, 30-61 years). Dystocia and postpartum complications were the cause of death in 18 beluga, accounting for 19% of the females >19 years old examined. The occurrence of parturition-associated complications, as well as mortality of calves <1 year old, have increased recently in this population and may be the probable cause of the recent decrease in the size of this population. One of the hypotheses proposed to explain the unusually high occurrence of some of the pathologic conditions observed in this population is chronic exposure to environmental contaminants. PMID:26374277

  19. Temporal trends (1987-2002) of persistent, bioaccumulative and toxic (PBT) chemicals in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Canada.

    PubMed

    Lebeuf, Michel; Nol, Michelle; Trottier, Steve; Measures, Lena

    2007-09-20

    Temporal trends of persistent, bioaccumulative and toxic (PBT) chemicals were examined in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary (SLE), Canada. Blubber samples of 86 adult belugas were collected from animals stranded on the shore of the SLE between 1987 and 2002 and analyzed for several regulated PBTs, including polychlorinated biphenyls (PCBs), p,p'dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordane (CHL) and related compounds, hexachlorocyclohexane (HCH) isomers, hexachlorobenzene (HCB) and Mirex. In addition, time trends of tris(4-chlorophenyl)methane (TCPMe) and tris(4-chlorophenyl)methanol (TCPMOH), two compounds that may origin from DDT formulations, were also examined. Concentrations of most of the PBTs examined had exponentially decreased by at least a factor of two (half-life time (t(1/2))<15 years) in beluga between 1987 and 2002 while no increasing trends were observed for any of the PBTs measured. The decreasing trends of PBT concentrations in SLE beluga may be due to a decline in contamination of its diet following North American and international regulations on the use and production of these compounds or by a change in its diet itself or by a combination of both. Some PBTs did not exhibit any significant trends in beluga possibly because the most intense elimination phase subsequent to legislative regulations occurred prior to the 1987-2002 time period. Other chemicals, such gamma-HCH, did not significantly decrease likely because they are still currently used in some restricted applications. Conversely, alpha-HCH showed a significant decreasing trend indicating that SigmaHCHs is not representative of all HCHs. Both TCPMe and TCPMOH exhibited no trends in beluga during the time period examined. The metabolic capacity of SLE beluga has apparently accelerated the depletion of at least one PBT, namely CB-28/31. A significant relationship between the half-life of PBTs in beluga and log Kow was observed for most of the chemicals examined. Several factors are expected to have influenced the temporal changes of PBT concentrations in beluga which limit the usefulness of this species as a bioindicator of changes in PBT contamination in the SLE ecosystem. PMID:17560630

  20. Immunotoxical evaluation of St. Lawrence beluga whales (Deiphinapterus leucas)

    SciTech Connect

    Guise, S. De; Fournier, M.; Martineau, D.; Beland, P.

    1995-12-31

    An isolated population of beluga whales live in the St. Lawrence estuary. From approximately 5,000 at the beginning of the century, they now number 500 and their number has not increased since the last 10 years. High concentrations of environmental contaminants including organohalogens (mostly PCBs and DDT), as well as heavy metals (mostly mercury and lead) and HAP exposure have been demonstrated in tissues of these animals. A high incidence of diverse and severe lesions including infections with mildly pathogenic bacteria and numerous tumors were found upon examination of carcasses from the same population. An immunotoxicological evaluation of St. Lawrence beluga whales compared to relatively unpolluted Arctic animals was undertaken to study the possibility of a contaminants induced immunosuppression which would explain the diversity and severity of those lesions. As a first step, several assays were developed to evaluate immune functions in beluga whales, and baseline data were established using Arctic animals. In vitro exposure of Arctic beluga lymphocytes to single contaminants present in St. Lawrence beluga blubber were also performed and showed a suppression of proliferation of lymphocytes with concentrations of mercury below those found in liver of adult St. Lawrence animals. Animal models were also developed to evaluate the immunotoxic potential of the mixture of contaminants found in blubber of St. Lawrence belugas. Rats were fed lipids from either St. Lawrence or Arctic belugas or a mixture of the two groups, and immune functions will be evaluated in these animals. Finally, the last step of the study will be to catch belugas in the St. Lawrence, evaluate their immune functions, compare them to those of Arctic animals and relate them to concentrations of the different contaminants measured in their blubber and plasma.

  1. Sivuqam Ungipaghaatangi (St. Lawrence Island Legends).

    ERIC Educational Resources Information Center

    Slwooko, Grace

    Transmitted orally for generations until the Eskimo language became a written one, the eleven St. Lawrence Island legends compiled in this volume for high school students tell of feats that were accomplished through supernatural power. Meant for both entertainment and instruction, the tales convey wise council indirectly through the conversations…

  2. Toxic compounds and health and reproductive effects in St. Lawrence Beluga Whales

    SciTech Connect

    Beland, P.; Michaud, R. ); DeGuise, S. Faculte de Medecine Veterinaire, St-Hyacinthe, Quebec ); Girard, C.; Lagace, A. ); Martineau, D. Cornell Univ., Ithaca, NY ); Muir, D.C.G. ); Norstorm, R.J. ); Pelletier, E. ); Ray, S. )

    1993-01-01

    An epidemiologic study was carried out over a period of 9 years on an isolated population of beluga whales (Delphinapterus leucas) residing in the St. Lawrence estuary (Quebec, Canada). More than 100 individual deaths were aged, and/or autopsied and analyzed for toxic compounds, and the population was surveyed for size and structure. Arctic belugas and other species of whales and seals from the St. Lawrence were used for comparison. Population dynamics: Population size appeared to be stable and modeling showed this stable pattern to result from low calf production and/or low survival to adulthood. Toxicology: St. Lawrence belugas had higher or much higher levels of mercury, lead, PCBs, DDT, Mirex, benzo[a]pyrene metabolites, equivalent levels of dioxins, furans, and PAH metabolites, and much lower levels of cadmium than Arctic belugas. In other St. Lawrence cetaceans, levels of PCBs and DDT were inversely related to body size, as resulting from differences in metabolic rate, diet, and trophic position, compounded by length of residence in the St. Lawrence basin. St. Lawrence belugas had much higher levels than predicted from body size alone; levels increased with age in both sexes, although unloading by females through the placenta and/or lactation was evidenced by overall lower levels in females and very high burdens in some calves. 45 refs., 4 figs., 5 tabs.

  3. Stratigraphic architecture and morphostructures of a recent glacio-isostatically forced-regressive delta: implications in terms of proglacial fluvial dynamics, North Shore of the St-Lawrence Estuary, Québec, Canada

    NASA Astrophysics Data System (ADS)

    Dietrich, Pierre; Ghienne, Jean-François; Schuster, Mathieu; Lajeunesse, Patrick; Deschamps, Rémy; Nutz, Alexis; Roquin, Claude; Duringer, Philippe

    2015-04-01

    Proglacial deltaic systems provide information about ice margins evolution, related glacio-isostatic rebound and proglacial fluvial dynamic during ice-sheet retreat. Here, we document a case study based on the North Shore of the St-Lawrence Estuary, Québec, Canada, recording the recession of the Laurentide Ice Sheet after the Last Glacial Maximum (Upper Wisconsinian-Holocene). The entire deltaic succession is exposed throughout coastal cliffs and river-cut terraces. Field investigations involve sedimentary logs, 14C dating and the characterization of morphosedimentary structures in the hinterlands. The delta initiates around 11 kyr Cal BP during an ice-front stabilization. Marine invasion on isostatically flexured lowlands led to the development of the Goldthwait Sea that reached a marine limit at the present-day 140 m elevation. At this time, ice contact and glaciomarine sediments were emplaced at the mouth of the major structural valleys. The subsequent glacial retreat farther inland turned the structural valleys into fjords into which deltas develop. The rapid fulfilling of these depocenters by glaciogenic sediments led to the emergence and coalescence of the deltas on the open sea. Lower delta front deposits are made up of mud while sand-sized, turbiditic deposits including facies related to supercritical flows (chutes, cyclic steps) prevail in the upper reaches. The delta plain is composed of gravelly facies deposited by braided streams. The progradation of the proglacial deltaic complex was about 10 km (thickness > 100 m) in only 1000 years in the open coast setting while the sea-level fall due to the glacio-isostatic rebound was up to 10 cm/yrs. This system remains active until the melting of the ice margins out of the catchment area at 10 kyr Cal BP. Sedimentary suites associated with the later paraglacial evolution comprise nearshore sand wedge (spit platform) and foreshore complexes. Throughout the entire proglacial deltaic development, no major fluvial incision occurred in spite of significant rates of sea-level fall (50m/1000 yrs). This owes to a fluvial equilibrium profile steeper than the descending regressive shoreline trajectory mainly due to an important glaciogenic sediment supply. Alternatively, fluvial entrenchment actively arose as soon as the ice margins retreated out of the catchment area in a context enduring lesser rates of sea-level fall. Fluvial entrenchment processes are explored, including buffer/buttress incision processes and the key role of bedrock thresholds, rate of sea level-fall and the drawdown of the glaciogenic/paraglacial sediment supply.

  4. Characterization and profiling of hepatic cytochromes P450 and phase II xenobiotic-metabolizing enzymes in beluga whales (Delphinapterus leucas) from the St. Lawrence River Estuary and the Canadian Arctic.

    PubMed

    McKinney, Melissa A; Arukwe, Augustine; De Guise, Sylvain; Martineau, Daniel; Béland, Pierre; Dallaire, André; Lair, Stéphane; Lebeuf, Michel; Letcher, Robert J

    2004-07-30

    Cytochromes P450 (CYP, phase I) and conjugating (phase II) enzymes can be induced by and influence the toxicokinetics (metabolism) and toxicity of xenobiotic contaminants in exposed organisms. Beluga whale (Delphinapterus leucas) from the endangered St. Lawrence (SL) River Estuary population exhibit deleterious health effects and various severe pathologies that have been associated with contaminant exposure. In contrast, such effects (e.g. reproductive and immunological impairment) are generally less frequent in less exposed populations in the Canadian Arctic (CA). In the present study, opportunistic sampling resulted in the collection immediately after death of liver tissue from a single female neonate SL beluga (SL6) and male and female CA beluga (n=10) from the Arviat region of western Hudson Bay, in addition to sampling of stranded carcasses of male and female SL beluga (n=5) at least 12 h postmortem. We immunologically characterized cross-reactive proteins of hepatic microsomal CYP1A, CYP2B, CYP3A, CYP2E, epoxide hydrolase (EH) and uridine diphosphoglucuronosyl transferase (UDPGT) isozymes. Cross-reactive proteins were found in all SL and CA beluga using anti-rat CYP1A1, anti-rainbow trout CYP3A, anti-human CYP2E1, anti-rabbit EH and anti-human UDPGT1A1 polyclonal antibodies (Abs), whereas faintly cross-reactive CYP2B proteins were only found in SL6 and the CA samples using an anti-rabbit CYP2B1 Ab. In corresponding catalytic activity assessments, only SL6 and all CA beluga microsomal samples exhibited CYP1A-mediated 7-ethoxyresorufin O-deethylase (EROD) activity (51-260 pmol/mg/min), CYP3A-mediated activity (113-899 pmol/mg/min) based on the formation of 6beta-hydroxytestosterone using a testosterone hydroxylase assay, and UDPGT activity (830-4956 pmol/mg/min) based on 1-naphthylglucuronide formation. The marginal cross-reactivity with the anti-CYP2B1 Ab and lack of catalytically measurable hydroxytestosterone isomers associated with CYP2B-type activity in all the SL and CA animals is suggestive of low CYP2B-type enzyme expression in beluga. The absence of measurable total P450 enzyme levels and catalytic activities in samples from the stranded SL belugas suggested catalytically inactive enzymes as a consequence of tissue degradation related due to the time delay of sample collection after death. However, all SL and CA animals demonstrated similar, immunologically cross-reactive phase I and II hepatic enzyme profiles, which is suggestive of the importance of metabolism in the toxicokinetics and fate of xenobiotics in animals from both populations PMID:15210296

  5. Methylsulfone polychlorinated biphenyl and 2,2-bis(chlorophenyl)-1,1-dichloroethylene metabolites in beluga whale (Delphinapterus leucas) from the St. Lawrence River estuary and western Hudson Bay, Canada

    SciTech Connect

    Letcher, R.J.; Norstrom, R.J.; Muir, D.C.G.; Sandau, C.D.; Koczanski, K.; Michaud, R.; De Guise, S.; Beland, P.

    2000-05-01

    Knowledge is limited regarding methylsulfone (MeSO{sub 2})-polychlorinated biphenyl (PCB), and especially MeSo{sub 2}-2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE), metabolites in cetacean species. The authors hypothesized that the ability of beluga whale (Delphinapterus leucas) to biotransform PCB and DDE compounds, and to form and degrade their MeSO{sub 2}-PCB and -DDE metabolites, is related to the capacity for xenobiotic metabolism. Adipose biopsies were collected from male and female beluga whale from distinct populations in the St. Lawrence River estuary (STL) and western Hudson Bay (WHB), Canada, which are contrasted by the exposure to different levels of cytochrome P450 enzyme-inducing, chlorinated hydrocarbon contaminants. The PCBs, DDTs, DDEs, 28 MeSO{sub 2} metabolites of 14 meta-para chlorine-unsubstituted PCBs, and four MeSO{sub 2} metabolites of 4,4{prime}- and 2,4{prime}-DDE were determined. The mean concentrations of total ({Sigma}-) MeSO{sub 2}-PCB in male STL beluga (230 ng/g), and ratios of {Sigma}-MeSO{sub 2}-PCB to {Sigma}-PCB (0.05) and {Sigma}-precursor-PCB (0.17) were approximately twofold higher, whereas the {Sigma}-precursor-PCB to {Sigma}-PCB ratio was approximately twofold lower, than in male WHB beluga. Both populations had a low formation capacity for MeSO{sub 2}-PCBs with {le} six chlorines (<4% of {Sigma}-MeSO{sub 2}-PCBs). The congener patterns were dominated by trichloro- and tetrachloro-MeSO{sub 2}-PCBs, and tetrachloro- and pentachloro-MeSO{sub 2}-PCBs in WHB and STL animals, respectively. In addition to 2- and 3-MeSO{sub 2}-4,4{prime}-DDE, two unknown MeSO{sub 2}-2,4{prime}-DDEs were detected. The mean 3-MeSO{sub 2}-4,4{prime}-DDE concentration in STL beluga (1.2 ng/g) was much greater than in WHB animals. The concentrations of 4,4{prime}-DDE, and not 3-MeSO{sub 2}-4,4{prime}-DDE, increased with age in male STL animals. The authors demonstrated that sulfone formation and clearance is related to metabolic capacity, and thus PCB, DDE, and MeSO{sub 2}-PCB and -DDE toxicokinetics differ for STL and WHB beluga. In the past, the capacity of odontocetes for PCB and DDE biotransformation leading to persistent sulfone formation and clearance is related to metabolic capacity, and thus PCB, DDE, and MeSO{sub 2}-PCB and -DDE toxicokinetics differ for STL and WHB beluga. In the past, the capacity of odontocetes for PCB and DDE biotransformation leading to persistent sulfone metabolites has been underestimated. More information is needed for other cetacean species and marine mammals. The results of this study indicate that MeSO{sub 2}-PCBs and -DDEs need to be included in the toxicologic risk assessment of PCB and DDT exposure in odontocetes, and perhaps for cetaceans in general.

  6. Indication of a Lombard vocal response in the St. Lawrence River beluga

    NASA Astrophysics Data System (ADS)

    Scheifele, P. M.; Andrew, S.; Cooper, R. A.; Darre, M.; Musiek, F. E.; Max, L.

    2005-03-01

    Noise pollution is recognized as a potential danger to marine mammals in general, and to the St. Lawrence beluga in particular. One method of determining the impacts of noise on an animal's communication is to observe a natural and repeatable response of the vocal system to variations in noise level. This is accomplished by observing intensity changes in animal vocalizations in response to environmental noise. One such response observed in humans, songbirds, and some primates is the Lombard vocal response. This response represents a vocal system reaction manifested by changes in vocalization level in direct response to changes in the noise field. In this research, a population of belugas in the St. Lawrence River Estuary was tested to determine whether a Lombard response existed by using hidden Markhov-classified vocalizations as targets for acoustical analyses. Correlation and regression analyses of signals and noise indicated that the phenomenon does exist. Further, results of human subjects experiments [Egan, J. J. (1966), Ph.D. dissertation; Scheifele, P. M. (2003), Ph.D. dissertation], along with previously reported data from other animal species, are similar to those exhibited by the belugas. Overall, findings suggest that typical noise levels in the St. Lawrence River Estuary have a detectable effect on the communication of the beluga. .

  7. Indication of a Lombard vocal response in the St. Lawrence River Beluga.

    PubMed

    Scheifele, P M; Andrew, S; Cooper, R A; Darre, M; Musiek, F E; Max, L

    2005-03-01

    Noise pollution is recognized as a potential danger to marine mammals in general, and to the St. Lawrence beluga in particular. One method of determining the impacts of noise on an animal's communication is to observe a natural and repeatable response of the vocal system to variations in noise level. This is accomplished by observing intensity changes in animal vocalizations in response to environmental noise. One such response observed in humans, songbirds, and some primates is the Lombard vocal response. This response represents a vocal system reaction manifested by changes in vocalization level in direct response to changes in the noise field. In this research, a population of belugas in the St. Lawrence River Estuary was tested to determine whether a Lombard response existed by using hidden Markhov-classified vocalizations as targets for acoustical analyses. Correlation and regression analyses of signals and noise indicated that the phenomenon does exist. Further, results of human subjects experiments [Egan, J. J. (1966), Ph.D. dissertation; Scheifele, P. M. (2003), Ph.D. dissertation], along with previously reported data from other animal species, are similar to those exhibited by the belugas. Overall, findings suggest that typical noise levels in the St. Lawrence River Estuary have a detectable effect on the communication of the beluga. PMID:15807036

  8. St. Lawrence blue whale vocalizations revisited: characterization of calls detected from 1998 to 2001.

    PubMed

    Berchok, Catherine L; Bradley, David L; Gabrielson, Thomas B

    2006-10-01

    From 1998 to 2001, 115 h of acoustic recordings were made in the presence of the well-studied St. Lawrence population of blue whales, using a calibrated omnidirectional hydrophone [flat (+/- 3 dB) response from 5 to 800 Hz] suspended at 50 m depth from a surface isolation buoy. The primary field site for this study was the estuary region of the St. Lawrence River (Québec, Canada), with most recordings made between mid-August and late October. During the recordings, detailed field notes were taken on all cetaceans within sight. Characterization of the more than 1000 blue whale calls detected during this study revealed that the St. Lawrence repertoire is much more extensive than previously reported. Three infrasonic (<20 Hz) and three audible range (30-200 Hz) call types were detected, with much time/frequency variation seen within each type. Further variation is seen in the form of call segmentation, which appears (through examination of Lloyd's Mirror interference effects) to be controlled at least partially by the whales. Although St. Lawrence blue whale call characteristics are similar to those of the North Atlantic, comparisons of phrase composition and spacing among studies suggest the possibility of population dialects within the North Atlantic. PMID:17069329

  9. Stocking young Atlantic salmon in St. Lawrence River system

    Thousands of young Atlantic salmonare released into the St. Regis River system (a tributary of the St. Lawrence River) in an effort to restore this diminished Lake Ontario fish population. The salmon were reared at the USGS Tunison Laboratory in Cortland, N.Y., and are released by USGS scienti...

  10. Stocking young Atlantic salmon in St. Lawrence River system

    Thousands of young Atlantic salmon are released into the St. Regis River system (a tributary of the St. Lawrence River) in an effort to restore this diminished Lake Ontario fish population. The salmon were reared at the USGS Tunison Laboratory in Cortland, N.Y., and are released by USGS scienti...

  11. Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).

    PubMed Central

    De Guise, S; Martineau, D; Béland, P; Fournier, M

    1995-01-01

    A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals. Functional and morphological changes have been demonstrated in thyroid gland and adrenal cortex in many species exposed to organochlorinated compounds, including seals. Morphological lesions, although different, were also found in belugas. Functional evaluation of thyroid and adrenal glands of contaminated (St. Lawrence) versus much less contaminated (Arctic) belugas is currently under way. Necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria, which suggests immunosuppression. Organochlorine compounds and other contaminants found in beluga whales cause immunosuppression in a variety of animal species including seals. Thirty-seven percent of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. This could be explained by two different mechanisms: high exposure to environmental carcinogens and suppression of immunosurveillance against tumors. Overall, St. Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time. PMID:7556028

  12. A Study of the St. Lawrence River Ecological Habitat

    ERIC Educational Resources Information Center

    Mesires, Maria

    2010-01-01

    Save the River, a grassroots advocacy group established in 1978, lobbies for policies to preserve the upper St. Lawrence River and uses the community's help to keep an eye on the existing habitats. Recently, they procured the Fresh Sound Foundation grant to support the development of new K-12 ecology curricula by local area teachers to educate

  13. Spending Time and Money: Memories of Life in St. Lawrences

    ERIC Educational Resources Information Center

    Abraham, Jane; Cooper, Mabel; Ferris, Gloria

    2010-01-01

    Mabel Cooper and Gloria Ferris spent their early adult life in St. Lawrence's Hospital in Caterham. This was in the late 1950s to early 1970s. This is their memories of how they spent their time. It includes the work they did and leisure. They also write about the tokens that were used in the hospital instead of money.

  14. A Study of the St. Lawrence River Ecological Habitat

    ERIC Educational Resources Information Center

    Mesires, Maria

    2010-01-01

    Save the River, a grassroots advocacy group established in 1978, lobbies for policies to preserve the upper St. Lawrence River and uses the community's help to keep an eye on the existing habitats. Recently, they procured the Fresh Sound Foundation grant to support the development of new K-12 ecology curricula by local area teachers to educate…

  15. St. Lawrence River Freeze-Up Forecast Procedure.

    ERIC Educational Resources Information Center

    Assel, R. A.

    A standard operating procedure (SOP) is presented for calculating the date of freeze-up on the St. Lawrence River at Massena, N.Y. The SOP is based on two empirical temperature decline equations developed for Kingston, Ontario, and Massena, N.Y., respectively. Input data needed to forecast freeze-up consist of the forecast December flow rate and…

  16. Evaluation of the contamination of marine algae (seaweed) from the St. Lawrence River and likely to be consumed by humans

    SciTech Connect

    Phaneuf, D.; Cote, I.; Dumas, P.; Ferron, L.A.; LeBlanc, A.

    1999-02-01

    The goal of the study was to assess the contamination of marine algae (seaweeds) growing in the St. Lawrence River estuary and Gulf of St. Lawrence and to evaluate the risks to human health from the consumption of these algae. Algae were collected by hand at low tide. A total of 10 sites on the north and south shores of the St. Lawrence as well as in Baie des Chaleurs were sampled. The most frequently collected species of algae were Fucus vesiculosus, Ascophyllum nodosum, Laminaria Longicruris, Palmaria palmata, Ulva lactuca, and Fucus distichus. Alga samples were analyzed for metals iodine, and organochlorines. A risk assessment was performed using risk factors. In general, concentrations in St. Lawrence algae were not very high. Consequently, health risks associated with these compounds in St. Lawrence algae were very low. Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems. For regular consumers, it would be preferable to choose species with low iodine concentrations, such as U. lactuca and P. palmata, in order to prevent potential problems. Furthermore, it would also be important to assess whether preparation for consumption or cooking affects the iodine content of algae. Algae consumption may also have beneficial health effects. Scientific literature has shown that it is a good source of fiber and vitamins, especially vitamin B{sub 12}.

  17. Inter-Annual Variability of the St. Lawrence Productivity: a Modeling Study

    NASA Astrophysics Data System (ADS)

    Chifflet, M.; Le Fouest, V.; Starr, M.; Saucier, F.; Zakardjian, B.

    2004-05-01

    The productivity of the St. Lawrence is strongly dependent on circulation and fresh water input. How natural climate variability or climate changes may affect the dynamics of this ecosystem need to be evaluated in order to improve its predictability. Here, we present results of a coupled 3D physical-ecosystem model of the Estuary and Gulf of St Lawrence that was developed to study the complex interactions between climate forcing and the productivity of biological resources at the base of the food chain. The physical model is a high resolution 3D baroclinic circulation model (5 km in the horizontal and 5 m in the vertical) that is presently operational for the St. Lawrence basin (Saucier et al. 2003). It includes a level 2.5 turbulent kinetic energy scheme and an ice module. The ecosystem model includes eight compartments : nitrate and ammonium, two classes of phytoplankton (diatoms and flagellates), two classes of zooplankton (microzooplankton and mesozooplankton), and two sizes of detritus (Le Fouest et al. 2004). This ecosystem model is driven by the physical model using realistic tidal, atmospheric and hydrologic forcing for three years: 1997 as a typical year with high ice cover and high runoff, 1999 as a warm and productive year with low runoff and low ice cover and 1998, an intermediate year with low ice cover and high runoff. The simulated results of the seasonal and inter-annual variability in ocean climate and primary production are compared to field observations from the Atlantic Zonal Monitoring Program. Particular attention is directed towards the influence of climatic and hydrologic factors that exert a control on the nutrient distribution, seasonal plankton biomass, timing and magnitude of the spring bloom and primary production. Our results highlight the strong influence of winter hydrographic processes on the inter-annual variability in the St. Lawrence productivity. Le Fouest, V., Zakardjian, B., Saucier, F. J., Starr, M. 2004. Physical and climatic induced subregional variability of planktonic production in a high latitude marginal sea : the Gulf of St. Lawrence (Canada), in preparation. Saucier, F. J., Roy, F., Gilbert, D., Pellerin, P., Ritchie H. 2003. Modeling the formation and circulation processes of water masses and sea ice in the Gulf of St. Lawrence, Canada. J. Geophys. Res., 108(C8):1-20.

  18. Holocene development of maritime ombrotrophic peatlands of the St. Lawrence North Shore in eastern Canada

    NASA Astrophysics Data System (ADS)

    Magnan, Gabriel; Garneau, Michelle; Payette, Serge

    2014-07-01

    Macrofossil analyses were used to reconstruct long-term vegetation successions within ombrotrophic peatlands (bogs) from the northern shorelines of the St. Lawrence Estuary (Baie-Comeau) and the Gulf of St. Lawrence (Havre-St-Pierre). Over the Holocene, the timing and the ecological context of peatland inception were similar in both regions and were mainly influenced by fluctuations in relative sea level. Peat accumulation started over deltaic sands after the withdrawal of the Goldthwait Sea from 7500 cal yr BP and above silt-clay deposits left by the Laurentian marine transgression after 4200 cal yr BP. In each region, the early vegetation communities were similar within these two edaphic contexts where poor fens with Cyperaceae and eastern larch (Larix laricina) established after land emergence. The rapid transitions to ombrotrophy in the peatlands of Baie-Comeau are associated with particularly high rates of peat accumulation during the early developmental stage. The results suggest that climate was more propitious to Sphagnum growth after land emergence in the Baie-Comeau area. Macrofossil data show that treeless Sphagnum-dominated bogs have persisted over millennia and that fires had few impacts on the vegetation dynamics. This study provides insight into peatland vegetation responses to climate in a poorly documented region of northeastern America.

  19. A Seaway Acoustic Observatory in Action: The St. Lawrence Seaway.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric; Giard, Samuel

    2016-01-01

    A setup for measuring spectral source levels (SSLs) of ships transiting along a seaway, the traffic density and shipping noise, is presented. The results feed shipping-noise modeling that reproduces the actual in situ observations to map shipping-noise variability over space and time for investigating its effects on aquatic organisms. The ship's SSL databank allows sorting the different contributors to total shipping noise for assisting in exploring mitigation approaches (e.g., fleet composition, rerouting). Such an acoustic observatory was deployed since November 2012 for a complete annual cycle of measurements in the deep downstream part of the St. Lawrence Seaway. PMID:26611065

  20. Sources and fluxes of mercury in the St. Lawrence River

    SciTech Connect

    Quemerais, B.; Rondeau, B.; Pham, T.T.; Gagnon, P.; Fortin, B.; Cossa, D.

    1999-03-15

    A mass balance approach, based essentially on the reconstruction of daily fluxes and circumscribed by strict error calculations, was designed to quantify the main mercury sources for the St. Lawrence and its tributaries, which constitute a large river system. High-frequency samplings were performed over an 18-month period (1955--1996) at the main water inputs and the mouth of the river. Minor tributaries and the Montreal effluent were also sampled. This strategy allowed models to be obtained that relate mercury concentrations in solution and in particles to the hydrological regime. The calculated budget was balanced relative to the calculated errors of the estimates. Gross mercury export from the river was found to be 5.9 kmol yr{sup {minus}1}. Tributaries and internal erosion of the river contributed equally for a total of 75% of this gross load, whereas the Upper St. Lawrence River, which is almost exclusively composed of Lake Ontario waters, accounted for less than 10%, and inventoried anthropogenic point sources accounted for about 5%. Dissolved mercury was mainly from north shore tributaries, and particulate mercury was largely from erosion of the river bed and banks. On the basis of the present results as well as estimates of atmospheric deposition from the literature it can be inferred that at least 88% of deposited mercury was retained in the watersheds.

  1. Evaluation of the contamination of marine algae (Seaweed) from the St. Lawrence River and likely to be consumed by humans.

    PubMed

    Phaneuf, D; Ct, I; Dumas, P; Ferron, L A; LeBlanc, A

    1999-02-01

    The goal of the study was to assess the contamination of marine algae (seaweeds) growing in the St. Lawrence River estuary and Gulf of St. Lawrence and to evaluate the risks to human health from the consumption of these algae. Algae were collected by hand at low tide. A total of 10 sites on the north and south shores of the St. Lawrence as well as in Baie des Chaleurs were sampled. The most frequently collected species of algae were Fucus vesiculosus, Ascophyllum nodosum, Laminaria longicruris, Palmaria palmata, Ulva lactuca, and Fucus distichus. Alga samples were analyzed for metals (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn), iodine, and organochlorines. A risk assessment was performed using risk factors (e.g., RfD of the U.S. EPA, ADI of Health Canada, etc.). In general, concentrations in St. Lawrence algae were not very high. This was especially true for mercury and the organochlorines, concentrations of which were very low or below detection limits. Consequently, health risks associated with these compounds in St. Lawrence algae were very low. Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems. For regular consumers, it would be preferable to choose species with low iodine concentrations, such as U. lactuca and P. palmata, in order to prevent potential problems. Furthermore, it would also be important to assess whether preparation for consumption or cooking affects the iodine content of algae. Algae consumption may also have beneficial health effects. Scientific literature has shown that it is a good source of fiber and vitamins, especially vitamin B12. PMID:10092431

  2. Mississippian conodonts, Lisburne Group, St. Lawrence Island, Alaska

    SciTech Connect

    Lane, H.R.; Ressmeyer, P.F.

    1985-04-01

    Late Mississippian conodonts recovered from two sections of the Lisburne Group exposed along the Ongoveyuk River, western St. Lawrence Island, are few, poorly preserved, yet relatively diverse. At the West Fork and East Fork Ongoveyuk sections, the lower, dark-colored, cherty beds yield conodonts that belong in the upper part of Lane Faunal Unit 8. They are correlatives of the upper St. Louis Formation in the Mississippi River Valley and, in northwest Alaska, are equivalent to the upper Nasorak and Kogruk Formations (Lisburne Group) along Nasorak Creek near Point Hope, and the Kogruk Formation at the Trail Creek, De Long Mountains, Misheguk Mountain quadrangle. The upper, light-colored, thicker-bedded interval at the West Fork exposure yields conodonts assignable to Lane Faunal unit 9 of latest Meramecian and earliest Chesterian age. This fauna occurs widely over North America in beds that correlate with the St. Genevieve Limestone in the Mississippi River Valley. On the Lisburne Peninsula, this interval correlates with at least a portion of the Kogruk Formation exposed at Niak Creek and Cape Lewis north of Point Hope. Conodont alteration indices (CAI) are very high and variable, ranging from 5.5 to 8.0, suggesting they resulted from contact rather than regional metamorphism.

  3. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  4. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  5. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  6. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  7. 50 CFR Table 45 to Part 679 - St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Table 45 Table 45 to Part 679—St. Lawrence Island Habitat...

  8. 77 FR 42642 - Safety Zone; City of Ogdensburg Fireworks, St. Lawrence River, Ogdensburg, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ...The Coast Guard is establishing a temporary safety zone on the St. Lawrence River, Ogdensburg, NY. This safety zone is intended to restrict vessels from a portion of the St. Lawrence River during the City of Ogdensburg Fireworks display. This temporary safety zone is necessary to protect spectators and vessels from the hazards associated with a fireworks...

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

    PubMed

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

    1997-07-01

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

  10. Wildlife as sentinels of human health effects in the Great Lakes--St. Lawrence basin.

    PubMed Central

    Fox, G A

    2001-01-01

    There is no existing formal, long-term program for gathering evidence of the incidence and severity of the health effects of toxic substances in wildlife. However, research-based studies of bald eagles, herring gulls, night herons, tree swallows, snapping turtles, mink, and beluga over the past 30 years have revealed a broad spectrum of health effects in the Great Lakes-St. Lawrence basin including thyroid and other endocrine disorders, metabolic diseases, altered immune function, reproductive impairment, developmental toxicity, genotoxicity, and cancer. These effects occurred most often and were most severe in the most contaminated sites (Green Bay, Saginaw Bay, Lake Ontario, the St. Lawrence estuary, and more recently, Lake Erie), some of which are International Joint Commission-designated Areas of Concern (AOCs). In all cases, a strong argument can be made for an environmental etiology, and in many cases for the involvement of persistent organic pollutants, particularly polychlorinated biphenyls, polychlorinated dibenzo-(italic)p(/italic)-dioxins, and polycyclic aromatic hydrocarbons. For some, the association with particular contaminants is consistent with controlled studies, and in some, dose-response relationships were documented. The biologic significance of these health impairments to the affected species is currently unclear, but they resemble those observed with increased incidence in human subpopulations in one or more AOCs. Formalizing health effects monitoring of sentinel wildlife species by the parties to the Canada-USA Great Lakes Water Quality Agreement is required. This would facilitate the optimal use of sentinel wildlife health data in a larger, epidemiologic weight-of-evidence context upon which to base decisions and policies regarding the effects of chemical exposures on human populations. PMID:11744503

  11. Wildlife as sentinels of human health effects in the Great Lakes--St. Lawrence basin.

    PubMed

    Fox, G A

    2001-12-01

    There is no existing formal, long-term program for gathering evidence of the incidence and severity of the health effects of toxic substances in wildlife. However, research-based studies of bald eagles, herring gulls, night herons, tree swallows, snapping turtles, mink, and beluga over the past 30 years have revealed a broad spectrum of health effects in the Great Lakes-St. Lawrence basin including thyroid and other endocrine disorders, metabolic diseases, altered immune function, reproductive impairment, developmental toxicity, genotoxicity, and cancer. These effects occurred most often and were most severe in the most contaminated sites (Green Bay, Saginaw Bay, Lake Ontario, the St. Lawrence estuary, and more recently, Lake Erie), some of which are International Joint Commission-designated Areas of Concern (AOCs). In all cases, a strong argument can be made for an environmental etiology, and in many cases for the involvement of persistent organic pollutants, particularly polychlorinated biphenyls, polychlorinated dibenzo-(italic)p(/italic)-dioxins, and polycyclic aromatic hydrocarbons. For some, the association with particular contaminants is consistent with controlled studies, and in some, dose-response relationships were documented. The biologic significance of these health impairments to the affected species is currently unclear, but they resemble those observed with increased incidence in human subpopulations in one or more AOCs. Formalizing health effects monitoring of sentinel wildlife species by the parties to the Canada-USA Great Lakes Water Quality Agreement is required. This would facilitate the optimal use of sentinel wildlife health data in a larger, epidemiologic weight-of-evidence context upon which to base decisions and policies regarding the effects of chemical exposures on human populations. PMID:11744503

  12. Earthquakes and Geological Structures of the St. Lawrence Rift System

    NASA Astrophysics Data System (ADS)

    Lamontagne, M.; Ranalli, G.

    2013-12-01

    The St. Lawrence Rift System (SLRS), which includes the Ottawa-Bonnechère and Saguenay grabens, is located well inside the North American plate. Most historic and the some 350 earthquakes recorded yearly occur in three main seismically active zones, namely Charlevoix (CSZ), Western Quebec (WQSZ), and Lower St. Lawrence (LSLSZ)). Outside these areas, most of the Canadian Shield and bordering regions have had a very low level of earthquake activity. In the SLRS, moderate to large earthquakes (Moment magnitude (M) 5.5 to M 7) are known to have occurred since 1663 causing landslides and damage mostly to unreinforced masonry elements of buildings located on ground capable of amplifying ground motions. Most earthquakes in these seismic zones share common characteristics such as mid- to upper crustal focal depths, no known surface ruptures and proximity to SLRS faults. Variations also exist such as vast seismically-active region (WQSZ and LSLSZ), presence of a large water body (CSZ and LSLSZ), and absence of SLRS faults near concentration of earthquakes (WQSZ). The CSZ is the best studied seismic zone and there, earthquakes occur in the Canadian Shield, mostly in a 30 X 85 km rectangle elongated along the trend of the St. Lawrence River with local variations in focal depth distribution. Faults related to the SLRS and to a meteor impact structure exist and earthquakes occur along the SLRS faults as well as in between these faults. Overall, the SLRS faults are probably reactivated by the larger earthquakes (M ≥ 4.5) of the 20th century (CSZ in 1925; WQCSZ in 1935 and 1944; Saguenay in 1988) for which we have focal mechanisms. We propose that caution be exercised when linking historical events that have uncertain epicentres with SLRS faults. Similarly, SLRS faults should not be necessarily considered to be the reactivated structures for most small to moderate earthquakes (M < 4.5). A good example of this is the earthquakes of the WQSZ that tend to concentrate in a well-defined NW-SE alignment with no obvious geological control, except perhaps, a hypothetical hotspot track. Two local factors can lead to the occurrence of SLRS earthquakes: weak faults or enhanced stress levels. We propose that local conditions, concentrated in a few seismic zones, can alter these factors and lead to the occurrence of earthquakes, especially those with M < 4.5. At a continent-wide scale, the correlation between the SLRS and earthquakes is appealing. We suggest, however, that pre-existing faults related to the SLRS do not explain all features of the seismicity. Seismicity is concentrated in more active areas, some with conspicuous normal faults and some with suspected weakening mechanisms such as intense pre-fracturing (e.g. due to a meteorite impact), the passage over a hot spot, or the presence of intrusions and lateral crustal density variations.

  13. Characterization of St. Lawrence blue whale vocalizations and their correlation with field observations

    NASA Astrophysics Data System (ADS)

    Berchok, Catherine L.

    During four field seasons from 1998--2001, 115 hours of acoustic recordings were made in the presence of the well-studied St. Lawrence population of blue whales. The primary field site for this study was the estuary region of the St. Lawrence River (Quebec, Canada) with most recordings made between mid-August and late October. Effort was concentrated in the daylight hours, although occasionally extending past nightfall. An inexpensive and portable recording system was built that was easy to deploy and provided quality recordings in a variety of sea conditions. It consisted of a calibrated omni-directional hydrophone with a flat (+/-3dB) response from 5Hz to 800Hz; and a surface isolation buoy to minimize the vertical movement of the sensor. During the recording sessions detailed field notes were taken on all blue whales within sight, with individual identities confirmed through photo-identification work between sessions. Notes were also taken on all other species sighted during the recording sessions. Characterization of the more than one-thousand blue whale calls detected during this study revealed that the St. Lawrence repertoire is much more extensive than previously reported. Three infrasonic (<20Hz) and four audible range (30--200Hz) call types were detected in this study, with much time/frequency variation seen within each type. The infrasonic calls were long (5--30s) in duration and arranged into regularly patterned series. These calls were similar in call characteristics and spacing to those detected in the North Atlantic, but had much shorter and more variable patterned series. The audible call types were much shorter (1--4s), and occurred singly or in irregularly spaced clusters, although a special patterning was seen that contained both regular and irregular spaced components. Comparison of the daily, seasonal, and spatial distributions of calling behavior with those of several biological parameters revealed interesting differences between the three call types examined. The trends seen suggest a migratory, reproductive, or foraging context for the infrasonic calls. A closer-range social context is suggested for the audible downsweeps, which have been detected in foraging situations as well as in courtship displays. The audible mixed-pattern call type appears to have a primarily reproductive context.

  14. Parameterization, regionalization and radiative transfer coherence of optical measurements acquired in the St-Lawrence ecosystem

    NASA Astrophysics Data System (ADS)

    Cizmeli, Servet Ahmet

    In-water biogeochemical constituents and bio-optical properties of the St-Lawrence Gulf and Estuary were monitored during 5 cruises conducted between 1997-2001 accross different seasons. Measured inherent optical properties (IOPs) included vertical profiles of the absorption and attenuation coefficients and the volume scattering function as well as absorption by particles, non-algal particles, phytoplankton and coloured dissolved organic matter (CDOM). Apparent Optical parameters (AOPs) included vertical profiles of the upwelling radiance and downwelling irradiance. The spectral shape of the major IOPs like absorption by phytoplankton, CDOM and non-algal particles as well as the particulate backscattering were parameterized using conventional models and adaptations of conventional models. Descriptive statistics of each variable in the collected dataset were analysed and compared with previous findings in the literature. The optical coherence of the measurements was verified using a radiative transfer closure approach. A complete set of IOP cross-sections for optically significant biogeochemical variables were generated. The magnitude and the spatial, temporal and spectral variation exhibited by the optically significant inwater biogeochemical constituents as well as the bio-optical parameters was consistent with our current knowledge of the ecosystem. The variation of the bio-optical parameters throughout the seasons was also coherent with our expectations. All the measured and derived parameters were found to vary within the ranges reported in the literature. Evidence was presented wherein the Gulf waters, which are usually considered as case I waters could also behave like case II waters. Moreover, spectral signatures exhibited by the IOPs and AOPs were coherent with the variation detected in the concentrations of the measured (optically significant) constituents. The extracted IOP cross-sections were consistent with the results of similar studies previously performed and could eventually be used in the estimation of the biogeochemical constituent concentrations given the related component IOPs. First-order radiative transfer closure was achieved; this underscored the validity of our experimental dataset based on considerations of higher level, integrative, physics. We argue that the current data collection campaign succeeded as a comprehensive framework for describing the behavior of the St-Lawrence bio-optical provinces within the context of remote sensing objectives. This bio-optical dataset should provide the basis for the development of a rigorous, satellite-based, remote sensing algorithm for the retrieval of near surface chlorophyll, fine-tuned to the local characteristics of the St-Lawrence system. Keywords. Phytoplankcton, bio-optical parameter, coloured dissolved organic matter, Apparent Optical parameter, inherent optical properties, radiative transfert, case II waters, suspended matter.

  15. Benthic nutrient fluxes along the Laurentian Channel: Impacts on the N budget of the St. Lawrence marine system

    NASA Astrophysics Data System (ADS)

    Thibodeau, Benoît; Lehmann, Moritz F.; Kowarzyk, Jacqueline; Mucci, Alfonso; Gélinas, Yves; Gilbert, Denis; Maranger, Roxane; Alkhatib, Mohammad

    2010-12-01

    Water column concentrations and benthic fluxes of dissolved inorganic nitrogen (DIN) and oxygen (DO) were measured in the Gulf of St. Lawrence and the Upper and Lower St. Lawrence Estuary (USLE and LSLE, respectively) to assess the nitrogen (N) budget in the St. Lawrence (SL) system, as well as to elucidate the impact of bottom water hypoxia on fixed-N removal in the LSLE. A severe nitrate deficit, with respect to ambient phosphate concentrations (N*˜-10 μmol L -1), was observed within and in the vicinity of the hypoxic bottom water of the LSLE. Given that DO concentrations in the water column have remained above 50 μmol L -1, nitrate reduction in suboxic sediments, rather than in the water column, is most likely responsible for the removal of fixed N from the SL system. Net nitrate fluxes into the sediments, derived from pore water nitrate concentration gradients, ranged from 190 μmol m -2 d -1 in the hypoxic western LSLE to 100 μmol m -2 d -1 in the Gulf. The average total benthic nitrate reduction rate for the Laurentian Channel (LC) is on the order of 690 μmol m -2 d -1, with coupled nitrification-nitrate reduction accounting for more than 70%. Using average nitrate reduction rates derived from the observed water column nitrate deficit, the annual fixed-N elimination within the three main channels of the Gulf of St. Lawrence and LSLE was estimated at 411 × 10 6 t N, yielding an almost balanced N budget for the SL marine system.

  16. Invasion by stages in the St Louis River estuary

    EPA Science Inventory

    The St. Louis River estuary is recognized as an invasive species “hotspot” - the harbor ranks among the top locations in the Great Lakes reporting the first occurrence of new, aquatic non-native species. To date, 18 non-native benthic invertebrate, 4 non-native crusta...

  17. Phenology of larval fish in the St. Louis River estuary

    EPA Science Inventory

    Little work has been done on the phenology of fish larvae in Great Lakes coastal wetlands. As part of an aquatic invasive species early detection study, we conducted larval fish surveys in the St. Louis River estuary (SLRE) in 2012 and 2013. Using multiple gears in a spatially ba...

  18. Larval fish distribution in the St. Louis River estuary

    EPA Science Inventory

    Our objective was to determine what study design, environmental, and habitat variables contribute to the distribution and abundance of larval fish in the St. Louis River estuary. Larval fish habitat associations are poorly understood in Great Lakes coastal wetlands, yet critical ...

  19. Comparison of St. Lawrence blue whale vocalizations with field observations

    NASA Astrophysics Data System (ADS)

    Berchok, Catherine; Bradley, David; Gabrielson, Thomas; Sears, Richard

    2003-04-01

    During four field seasons from 1998-2001, vocalizations were recorded in the presence of St. Lawrence blue whales using a single omni-directional hydrophone. Both long duration infrasonic calls (~18 Hz, 5-20 s) as well as short duration higher frequency calls (85-25 Hz, ~2 s) were detected and compared with field observations. Two trends were noted. First, the long infrasonic call series were concentrated primarily in the deep (300 m) channel. These call series appear to compare well with blue whale vocalizations recorded by others in the deep open ocean. Second, the shorter audible calls were more evenly distributed over bathymetry and seem to be a form of short distance communication with at least one case occurring during an agonistic interaction. A comparison of these calls with biological parameters such as density of whales in the area, percentages of paired versus single whales, and numbers of males versus females will also be discussed. [Project supported by ARL/PSU, NSF, and the American Museum of Natural History.

  20. Modelling spatial distribution of epibenthic communities in the Gulf of St. Lawrence (Canada)

    NASA Astrophysics Data System (ADS)

    Moritz, Charlotte; Lévesque, Mélanie; Gravel, Dominique; Vaz, Sandrine; Archambault, Diane; Archambault, Philippe

    2013-04-01

    Correlative habitat models using relationships between marine organisms and their surrounding environment can be used to predict species distribution, and the results can assist management of human activities sharing the marine space (e.g. fisheries, MPAs, tourism). Here, epi-benthic megafauna was sampled at 755 stations in the Lower Estuary and Northern Gulf of St. Lawrence (EGSL) each summer between 2006 and 2009. We combined various types of multivariate analyses to 1) describe the structure and spatial distribution of benthic communities, 2) analyse the relationship between these communities and environmental parameters, and subsequently 3) build a community distribution model to predict the spatial distribution of the communities, creating community distribution maps covering the entire area to be used for marine management and conservation. We identified distinct benthic communities in the study area that closely correlate with the 200 m depth contour and with major environmental variables. A redundancy analysis revealed that communities were associated with depth, oxygen saturation, temperature, bottom current, seabed uniformity, distance to coast and type of sediment. Together these environmental descriptors explained 38% of the variation in megafaunal community composition. The environmental variables were used to build a community distribution model using generalized linear models to predict high and low suitability zones of each community in the EGSL.

  1. Contamination and biomarkers in the great blue heron, an indicator of the state of the st. Lawrence river.

    PubMed

    Champoux, Louise; Rodrigue, Jean; Trudeau, Suzanne; Boily, Monique H; Spear, Philip A; Hontela, Alice

    2006-02-01

    In 1996-1997, nine breeding colonies of the great blue heron on the St. Lawrence River and its estuary (Québec, Canada) were investigated in the framework of a biomonitoring program. Fledglings from colonies in freshwater were more contaminated with mercury, PCBs and many organic contaminants than those from estuarine colonies. The level of contamination in the St. Lawrence River is generally below the levels of toxicological effects for the great blue heron. The molar ratio of retinol: retinyl palmitate in heron eggs was correlated with total PCBs (r=0.79) and Mirex (r=0.90). In plasma, all biochemical parameters were significantly different between freshwater and marine colonies. Plasma retinol concentrations at the Dickerson and Hérons colonies were significantly lower compared with those at Grande Ile (p<0.05) and Steamboat (p<0.001). Based on retinoid and beta-carotene concentrations in eggs, low plasma retinol was not associated with possible dietary deficiency. Plasma retinol was negatively correlated with many PCB congeners, total PCBs (r=-0.78), p,p'-DDE, trans-nonachlor and alpha-HCH. Similarly, the hormone T3 was correlated with many PCB congeners, total PCBs (r=-0.69) and the same organochlorine chemicals. Plasma LDH concentrations were different among freshwater colonies, Grande Ile and Hérons colonies having LDH values significantly greater than those of Steamboat (respectively, p<0.05 and p<0.01). Globally, the health status of the St. Lawrence great blue heron population was judged to be acceptable, however, several biomarkers indicated positive responses to contaminants. PMID:16400530

  2. Automatic recognition of fin and blue whale calls for real-time monitoring in the St. Lawrence.

    PubMed

    Mouy, Xavier; Bahoura, Mohammed; Simard, Yvan

    2009-12-01

    Monitoring blue and fin whales summering in the St. Lawrence Estuary with passive acoustics requires call recognition algorithms that can cope with the heavy shipping noise of the St. Lawrence Seaway and with multipath propagation characteristics that generate overlapping copies of the calls. In this paper, the performance of three time-frequency methods aiming at such automatic detection and classification is tested on more than 2000 calls and compared at several levels of signal-to-noise ratio using typical recordings collected in this area. For all methods, image processing techniques are used to reduce the noise in the spectrogram. The first approach consists in matching the spectrogram with binary time-frequency templates of the calls (coincidence of spectrograms). The second approach is based on the extraction of the frequency contours of the calls and their classification using dynamic time warping (DTW) and the vector quantization (VQ) algorithms. The coincidence of spectrograms was the fastest method and performed better for blue whale A and B calls. VQ detected more 20 Hz fin whale calls but with a higher false alarm rate. DTW and VQ outperformed for the more variable blue whale D calls. PMID:20000904

  3. Influence of summer water-level variability on St. Lawrence River-wetland fish assemblages

    USGS Publications Warehouse

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

    2008-01-01

    Water-level and associated variability are substantial influences on wetland and shallow aquatic communities. The Akwesasne Wetland Complex is an extensive St. Lawrence River system affected by water regulation. The responses of fish assemblages to short-term summer water-level variation were examined throughout this section of the St. Lawrence River and its tributaries. An influence of water-level variability was detected on abundance of three common species [bluntnose minnow (Pimephales notatus), rock bass (Amboplites rupestris), and white sucker (Catastomus commersonii)] and explained 30-44% of variation. This influence has implications for water regulation and natural resource management, and a larger scope evaluation may reveal more extensive effects.

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ... Central Bonnie Castle, 31 Western Plus Hotel Inn, St. Lawrence 4487 Lake Avenue. Hotel & Suites, High School, Holland St. Europa, Mont Blanc West Room, 805 Harbour Sanderson Rm, Auditorium, 5891 Room,...

  5. 50 CFR Figure 17 to Part 679 - Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Northern Bering Sea Research Area and St. Lawrence Island Habitat Conservation Area 17 Figure 17 to part 679 Wildlife and Fisheries FISHERY... Sea Research Area and St. Lawrence Island Habitat Conservation Area ER25JY08.011...

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

    USGS Publications Warehouse

    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.

  7. St. Lawrence River ecosystem monitoring: Selection of bioindicators and biomarkers of contamination and health

    SciTech Connect

    Champoux, L.; DesGranges, J.L.; Rodrigue, J.; Trudeau, S.; Hontela, A.; Boily, M.; Spear, P.A.

    1995-12-31

    The St. Lawrence River is contaminated by a large quantity of toxic substances from many sources, This contamination comes from the Great Lakes, as well as from industrial, urban and agricultural sources along its shores. The St. Lawrence Action Plan has, among other objectives, the goals of reducing the toxic inputs and the development of a surveillance network of the condition of the river. This network will include the selection of indicator species to follow the contamination of the trophic web to evaluate the success of the cleanup. It will also integrate ecotoxicological and demographic information to measure the effects of these toxic substances on living organisms and to follow the health of the system, in an ecosystemic approach. A number of species have been preselected on the basis of different ecological and physiological criteria. The Great Blue Heron and the Blackcrowned Night Heron, among other species, have been evaluated as indicator species for this network. Eggs and fledglings have been collected for contaminant and biochemical analysis from 1991 through 1994. Demographic data have also been collected. The data are compared between the two species, between St. Lawrence River colonies and to control colonies, as well as with data from the literature. In general, contamination levels are below those found in other regions and no effects on populations have been observed. However, preliminary results suggest that some of the biomarkers tested may be sensitive early indicators of wildlife contamination and health in the St. Lawrence River.

  8. Comparison of Lake Ontario and St. Lawrence River hydrologic droughts and their relationship to climate indices

    NASA Astrophysics Data System (ADS)

    Biron, Stacey; Assani, Ali A.; Frenette, Jean-Jacques; Massicotte, Philippe

    2014-02-01

    Five characteristics (intensity or magnitude, duration, frequency, timing, and variability) of drought, defined using the threshold level method (TLM) and recorded in mean annual water levels in Lake Ontario and the St. Lawrence River from 1918 to 2010, were compared. Timing is the only characteristic that is different for the two water bodies. For Lake Ontario, the most intense drought occurred in the 1930s, whereas in the St. Lawrence River, intense droughts took place in the 1960s and 2000s. The Lake Ontario drought produced two shifts in mean before (decrease) and after (increase) the 1930s. The change in variance that took place in the 1960s is thought to be related to the construction of locks during the digging of the seaway. The droughts that affected the St. Lawrence River had no impact on the stationarity (mean and variance) of the annual mean water level series. Analysis of the correlation between drought severity and climate indices revealed that years characterized by very weak to moderate drought are significantly correlated with PDO (Pacific Decadal Oscillation), while those characterized by intense drought are correlated with NAO (North Atlantic Oscillation). Both climate indices are negatively correlated with Lake Ontario water levels, while they are positively correlated with St. Lawrence River levels. The study suggests that NAO may be used to predict the driest years for the two water bodies.

  9. DAMAGE ASSESSMENT STUDIES FOLLOWING THE NEPCO 140 OIL SPILL ON THE ST. LAWRENCE RIVER

    EPA Science Inventory

    The primary objective of this two-and-one half year research effort was to determine the environmental and economic impacts of the NEPCO 140 oil spill. This spill occurred in the freshwater environment of the St. Lawrence River on June 23, 1976. The cleanup operation, which cost ...

  10. 77 FR 30443 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ..., issue of the Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting.... Coast Guard Sector Buffalo; telephone 716-843-9343, email SectorBuffaloMarineSafety@uscg.mil . If you... the St. Lawrence River near Alexandria Bay, NY. The Captain of the Port Buffalo has determined...

  11. 77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ...-366-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal..., St. Lawrence River, Alexandria Bay, NY in the Federal Register (77 FR 30443). We received no letters..., call or email LT Christopher Mercurio, Chief of Waterway Management, U.S. Coast Guard Sector...

  12. BIOREMEDIATION AND BIORESTORATION OF A CRUDE OIL CONTAMINATED FRESHWATER WETLAND ON THE ST. LAWRENCE RIVER

    EPA Science Inventory

    Biostimulation by nutrient enrichment and phytoremediation were studied for the restoration of an acutely stressed freshwater wetland experimentally exposed to crude oil. The research was carried out along the shores of the St. Lawrence River at Ste. Croix, Quebec, Canada. The ...

  13. A threatened beluga (Delphinapterus leucas) population in the traffic lane: vessel-generated noise characteristics of the Saguenay-St. Lawrence Marine Park, Canada.

    PubMed

    McQuinn, Ian H; Lesage, Vronique; Carrier, Dominic; Larrive, Genevive; Samson, Yves; Chartrand, Sylvain; Michaud, Robert; Theriault, James

    2011-12-01

    The threatened resident beluga population of the St. Lawrence Estuary shares the Saguenay-St. Lawrence Marine Park with significant anthropogenic noise sources, including marine commercial traffic and a well-established, vessel-based whale-watching industry. Frequency-dependent (FD) weighting was used to approximate beluga hearing sensitivity to determine how noise exposure varied in time and space at six sites of high beluga summer residency. The relative contribution of each source to acoustic habitat degradation was estimated by measuring noise levels throughout the summer and noise signatures of typical vessel classes with respect to traffic volume and sound propagation characteristics. Rigid-hulled inflatable boats were the dominant noise source with respect to estimated beluga hearing sensitivity in the studied habitats due to their high occurrence and proximity, high correlation with site-specific FD-weighted sound levels, and the dominance of mid-frequencies (0.3-23 kHz) in their noise signatures. Median C-weighted sound pressure level (SPL(RMS)) had a range of 19 dB re 1 ?Pa between the noisiest and quietest sites. Broadband SPL(RMS) exceeded 120 dB re 1 ?Pa 8-32% of the time depending on the site. Impacts of these noise levels on St. Lawrence beluga will depend on exposure recurrence and individual responsiveness. PMID:22225023

  14. Vertical distribution and diel migration of macrozooplankton in the St. Lawrence marine system (Canada) in relation with the cold intermediate layer thermal properties

    NASA Astrophysics Data System (ADS)

    Harvey, Michel; Galbraith, Peter S.; Descroix, Aurélie

    2009-01-01

    Vertical distribution of various species and stages of macrozooplankton (euphausiacea, chaetognatha, cnidaria, mysidacea, amphipoda) were determined for different times of the day and related to the physical environment. Stratified sampling with the BIONESS was carried out during seven cruises in spring and fall 1998, 2000, and 2001, and fall 1999, in two different habitats in the St. Lawrence marine system: the lower St. Lawrence Estuary and the NW Gulf of St. Lawrence. Our results indicate that the various macrozooplankton species were distributed throughout the whole water column including the surface layer, the cold intermediate layer (CIL), and the deep layer at different times of day and night in both areas during all periods. Moreover, three types of migrational patterns were observed within this zooplanktonic community: (1) nocturnal ascent by the whole population, (2) segregation into two groups; one which performed nocturnal accent and another which remained in the deep, and (3) no detectable migration. We also observed that the diel vertical migration (DVM) amplitude in most of the macrozooplankton species varied as a function of physical factors, in particular the spatio-temporal variations of the CIL thermal properties, including the upper and the lower limits of the CIL and the depth of the CIL core temperature. Finally, the different DVM patterns coupled with estuarine circulation patterns and bottom topography could place animals in different flow regimes by night and by day and contribute to their retention (aggregation) and/or dispersion in different areas, time of the day, and seasons.

  15. Constraints on Lake Agassiz discharge through the late-glacial Champlain Sea (St. Lawrence Lowlands, Canada) using salinity proxies and an estuarine circulation model

    USGS Publications Warehouse

    Katz, B.; Najjar, R.G.; Cronin, T.; Rayburn, J.; Mann, M.E.

    2011-01-01

    During the last deglaciation, abrupt freshwater discharge events from proglacial lakes in North America, such as glacial Lake Agassiz, are believed to have drained into the North Atlantic Ocean, causing large shifts in climate by weakening the formation of North Atlantic Deep Water and decreasing ocean heat transport to high northern latitudes. These discharges were caused by changes in lake drainage outlets, but the duration, magnitude and routing of discharge events, factors which govern the climatic response to freshwater forcing, are poorly known. Abrupt discharges, called floods, are typically assumed to last months to a year, whereas more gradual discharges, called routing events, occur over centuries. Here we use estuarine modeling to evaluate freshwater discharge from Lake Agassiz and other North American proglacial lakes into the North Atlantic Ocean through the St. Lawrence estuary around 11.5 ka BP, the onset of the Preboreal oscillation (PBO). Faunal and isotopic proxy data from the Champlain Sea, a semi-isolated, marine-brackish water body that occupied the St. Lawrence and Champlain Valleys from 13 to 9 ka, indicate salinity fell about 7-8 (range of 4-11) around 11.5 ka. Model results suggest that minimum (1600 km3) and maximum (9500 km3) estimates of plausible flood volumes determined from Lake Agassiz paleoshorelines would produce the proxy-reconstructed salinity decrease if the floods lasted <1 day to 5 months and 1 month to 2 years, respectively. In addition, Champlain Sea salinity responds very quickly to the initiation (within days) and cessation (within weeks) of flooding events. These results support the hypothesis that a glacial lake flood, rather than a sustained routing event, discharged through the St. Lawrence Estuary during the PBO. ?? 2011 Elsevier Ltd.

  16. Contaminant exposure in Montrealers of Asian origin fishing the St. Lawrence River: Exploratory assessment

    SciTech Connect

    Kosatsky, T.; Przybysz, R.; Shatenstein, B.; Weber, J.P.; Armstrong, B.

    1999-02-01

    Fishing and fish consumption are widely practiced among members of certain ethnocultural groups. Information assessment led them to ascribe high levels of consumption of locally caught sportfish to Montrealers of Asian origin and to hypothesize that their choices of species and fish organs differ from those of the majority group. An exploratory assessment of contaminant bioindicators reflective of St. Lawrence river fish consumption was conducted in late 1995 among nine Vietnamese and nine Bangladeshi Montreal sportfishers identified by community contacts. Vietnamese participants, six men and three women, were 27--70 years of age and had immigrated to Canada 3--20 years earlier. In contrast, the nine Bangladeshi males aged 28--41 years had been in Canada for 2--13 years. Bioindicator concentrations among Bangladeshi and Vietnamese participants are compared to those found for majority-community Montreal-area high-level consumers recruited on the St. Lawrence River during winter 1995.

  17. Influence of the St. Lawrence Island Polynya upon the Bering Sea benthos

    NASA Astrophysics Data System (ADS)

    Grebmeier, Jacqueline M.; Cooper, Lee W.

    1995-03-01

    The influence of a polynya, a persistent ice-free region, on water column production and subsequent transport to the shallow continental shelf benthos of the Bering Sea was evaluated by studying spatial patterns of organic material deposition, benthic biomass, community sediment metabolism, benthic population structure, and other potential indicators of enhanced organic carbon transport to benthic communities underlying the St. Lawrence Island Polynya. Despite suggestions that polynyas may be important localized centers of primary production in polar waters, we found that the St. Lawrence Island Polynya does not obviously enhance the biomass of benthic communities directly below the polynya. However, southward flowing, baroclinic currents generated as a result of brine injection at the polynya edge do appear to have an influence on the biomass and ecological structure of Bering Sea benthic communities south of St. Lawrence Island. These currents appear to affect mean sediment oxygen consumption, surface organic carbon/nitrogen ratios, total organic content, and bottom water ammonia by sweeping phytodetrital matter south and to the west of the island. A particle-reactive, short-lived, natural radioisotope, 7Be, used as an indicator of rapid (days to weeks) deposition of particulate material from the water column, was detected only in surface sediments to the southwest of the island, indicating enhancement of particle deposition to the southwest of the island. Finally, the 18O content of tunicate cellulose was highest in the polynya region, consistent with increased filter feeding in the late winter when the polynya is present, and presumably promoting primary production in the open water. The Anadyr Current, consisting of nutrient-rich, deeper Bering Sea water that is upwelled onto the shelf in the Gulf of Anadyr, flows west to east in the region south of St. Lawrence Island throughout the year and is the major forcing function for high production in the region. The interaction of Anadyr Water with the winter/spring ephemeral polynya and associated baroclinic currents combine to positively influence benthic communities.

  18. Influence of the St. Lawrence island Polynya upon the Bering Sea benthos

    SciTech Connect

    Grebmeier, J.M.; Cooper, L.W.

    1995-03-15

    The influence of a polynya, a persistent ice-free region, on water column production and subsequent transport to the shallow continental shelf benthos of the Bering Sea was evaluated by studying spatial patterns of organic material deposition, benthic biomass, community sediment metabolism, benthic population structure, and other potential indicators of enhanced organic carbon transport to benthic communities underlying the St. Lawrence Island Polynya. Despite suggestions that polynyas may be important localized centers of primary productions in polar waters, the authors found that the St. Lawrence Island Polynya does not obviously enhance the biomass of benthic communities directly below the polynya. However, southward flowing, baroclinic currents generated as a result of brine injection at the polynya edge do appear to have an influence on the biomass and ecological structure of Bering Sea benthic communities south of St. Lawrence Island. These currents appear to affect mean sediment oxygen consumption, surface organic carbon/nitrogen ratios, total organic content, and bottom water ammonia by sweeping phytodetrital matter south and to the west of the island. A particle-reactive, short-lived, natural radioisotope, {sup 7}Be, used as an indicator of rapid (days to weeks) deposition of particulate material from the water column, was detected only in surface sediments to the southwest of the island, indicating enhancement of particle deposition to the southwest of the island. Finally, the {sup 18}O content of tunicate cellulose was highest in the polynya region, consistent with increased filter feeding in the late winter when the polynya is present. The Anadyr Current, consisting of nutrient-rich, deeper Bering Sea water that is upwelled onto the shelf in the Gulf of Anadyr, flows west to east in the region south of St. Lawrence Island throughout the year and is the major forcing function for high production in the region. 76 refs., 13 figs., 5 tabs.

  19. Budget and sources of suspended sediment transported in the St. Lawrence River, Canada

    NASA Astrophysics Data System (ADS)

    Rondeau, Bernard; Cossa, D.; Gagnon, P.; Bilodeau, L.

    2000-01-01

    A mass balance budget of the suspended sediment in the St. Lawrence River was established for the sector stretching from Cornwall, Ontario, to Quebec City, Quebec, for the period 1989-1993. The approach consisted of analysing the amount of sediment contributed by the different tributaries, on a watershed-by-watershed basis, through sediment concentration-discharge models incorporating more than 4000 data points collected since 1983. Lake Ontario contributes less than 3% of the particulate load at Quebec City, while St. Lawrence tributaries on the south and north shores contribute 19% and 13%, respectively, of the sediment load. Our findings indicate that nearly 65% of the suspended sediments come from erosion of the bed and banks of the St. Lawrence River. This finding is broadly supported by numerous geomorphological and sedimentological observations and is consistent with the geological history of the river and the structures built on its banks in recent decades. Upstream-downstream mass balance studies conducted on individual river sectors indicate that the sources of erosion are located mainly in the Beauharnois Canal region, between Montreal and Les Grèves, and further downstream, between the outlet of Lake Saint-Pierre and Portneuf.

  20. Research management in the Great Lakes and St. Lawrence River basins: Challenges and opportunities

    SciTech Connect

    Rosa, C.T. de; Rosemond, Z.A.; Cibulas, W.; Gilman, A.P.

    1999-04-01

    Research management in the Great Lakes and St. Lawrence River basins is both challenging and filled with opportunities. From the perspective of public health practice, research management is more than just research managers managing discrete programs; it requires everyone involved in the process to become active participants, including researchers, communities,l potential interest groups, policymakers, and other stakeholders. Agencies, organizations, and individuals responsible for managing research and resources in the Great Lakes and St. Lawrence River basins are facing problems of decreased research funding, data gaps, and research quality. Managers of research and resources in the basins face many challenges as they address these problems. They are challenged with strengthening the link between research and management in the face of decreasing resources and increasing expectations of results and findings while extending those results and findings to public health practice. A number of actions and activities have been proposed that can lead to better management of constrained programs, pooled resources, partnerships, targeted priorities, and improved effectiveness. With guidance and assistance from the International Joint Commission (IJHC), research managers in the Great Lakes and St. Lawrence River basins who have initiated and maintained traditional research programs based on sound science are now adopting different and innovative management strategies.

  1. Lactational Transfer of Polychlorinated-Biphenyls (PCBs) and Other Organochlorines in St. Lawrence Beluga Whales (Delphinapterus leucas).

    PubMed

    Cadieux, Marc A; Muir, Derek C G; Béland, Pierre; Hickie, Brendan E

    2016-01-01

    This study uses an individual-based contaminant bioaccumulation model for marine mammals to explore factors controlling the transfer of PCBs from mother to calf via nursing in beluga from the St. Lawrence Estuary. Beluga blubber samples (n = 46), along with four matched milk samples from stranded animals over the 1986-1994 period were used for comparison with modelled results. Based on 68 POPs, including 48 PCBs and 20 other organochlorine compounds, milk:blubber ratios were 0.65 between log K OW 3-6.5, then decreased to 0.1 at log K OW 8. Model simulations based on this relationship indicated females were transferring PCBs that were relatively very hydrophobic and highly chlorinated less readily than their lower chlorinated counterparts, resulting in an enriched concentration of very hydrophobic congeners in nursing females relative to adult males. There was very good agreement between observed and modelled male:female PCB concentration ratios. Four females within our dataset (15 %) had male-like ΣPCB concentrations as well as male-like congener profiles, suggesting that these individuals may have had a reduced or limited nursing history. PMID:26323485

  2. A predictive model for floating leaf vegetation in the St. Louis River Estuary

    EPA Science Inventory

    In July 2014, USEPA staff was asked by MPCA to develop a predictive model for floating leaf vegetation (FLV) in the St. Louis River Estuary (SLRE). The existing model (Host et al. 2012) greatly overpredicts FLV in St. Louis Bay probably because it was based on a limited number of...

  3. Shark predation on migrating adult American eels (Anguilla rostrata) in the Gulf of St. Lawrence.

    PubMed

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin; Aarestrup, Kim; Campana, Steven E; Stokesbury, Michael J W; Dodson, Julian J

    2012-01-01

    In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C-too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day) during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks. PMID:23082131

  4. Shark Predation on Migrating Adult American Eels (Anguilla rostrata) in the Gulf of St. Lawrence

    PubMed Central

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin; Aarestrup, Kim; Campana, Steven E.; Stokesbury, Michael J. W.; Dodson, Julian J.

    2012-01-01

    In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C—too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day) during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks. PMID:23082131

  5. The influence of wind and ice on spring walrus hunting success on St. Lawrence Island, Alaska

    NASA Astrophysics Data System (ADS)

    Huntington, Henry P.; Noongwook, George; Bond, Nicholas A.; Benter, Bradley; Snyder, Jonathan A.; Zhang, Jinlun

    2013-10-01

    St. Lawrence Island Yupik hunters on St. Lawrence Island, Alaska, take hundreds of Pacific walrus (Odobenus rosmarus divergens) each year. The harvest and associated effort (hunting trips taken), however, are variable from year to year and also from day to day, influenced by physical environmental factors among other variables. We used data from 1996 to 2010 to construct generalized additive models (GAMs) to examine several relationships among the variables. Physical factors explained 18% of the variability in harvest in Savoonga and 25% of the variability in effort; the corresponding figures for Gambell were 24% and 32%. Effort alone explained 63% of the harvest in Savoonga and 59% in Gambell. Physical factors played a relatively smaller role in determining hunting efficiency (walrus taken per hunting trip), explaining 15% of the variability in efficiency in Savoonga and 22% in Gambell, suggesting that physical factors play a larger role in determining whether to hunt than in the outcome of the hunt once undertaken. Combining physical factors with effort explained 70% of the harvest variability in Savoonga and 66% in Gambell. Although these results indicate that other factors (e.g. fuel prices, socioeconomic conditions) collectively cause a greater share of variability in harvest and effort than ice and wind, at least as indicated by the measures used as predictors in the GAMs, they also suggest that environmental change is also likely to influence future harvest levels, and that climate models that yield appropriately scaled data on ice and wind around St. Lawrence Island may be of use in determining the magnitude and direction of those influences.

  6. Age and growth of lake sturgeon in the upper St. Lawrence River

    USGS Publications Warehouse

    Johnson, J.H.; Dropkin, D.S.; LaPan, S.R.; McKenna, J.E., Jr.; Klindt, R.M.

    1998-01-01

    The growth of lake sturgeon (Acipenser fulvescens) over time in the upper St. Lawrence River was examined. Growth of lake sturgeon collected during 1993 and 1994 below Robert Moses Dam near Massena, New York, was compared to that reported for the same population almost 25 years earlier. The data suggest that lake sturgeon growth was similar to that reported in the previous study. However, significant differences in the elevations of regression models between males and fish of unknown sex in both data sets suggest possible sexual dimorphism in growth at younger ages.

  7. Recent wave climate and expected future changes in the seasonally ice-infested waters of the Gulf of St. Lawrence, Canada

    NASA Astrophysics Data System (ADS)

    Ruest, Benoit; Neumeier, Urs; Dumont, Dany; Bismuth, Eliott; Senneville, Simon; Caveen, James

    2016-01-01

    A new method is developed to evaluate the wave climate in the Gulf of St. Lawrence (GSL) with the consideration of wave attenuation by sea ice. Ice concentrations outputs from a regional oceanic model are used to attenuate, in post-processing, significant wave height ( H s ) time-series simulated with a parametric wave model for ice-free conditions. Reanalysis data is used to compute GSL wave climate for the 1981-2010 period with and without wave attenuation by sea ice. Outputs from two simulations from the Canadian Regional Climate Model are also used to evaluate how GSL wave climate should evolve during the twenty first century according to the SRES-A2 greenhouse gases emission scenario. Results show that sea ice has reduced extreme H s on the GSL by about 12 % on average over the 1981-2010 period but its impact on wave climate should become negligible by 2100 except in the St. Lawrence Estuary. Over the twenty first century, an increase of extreme H s on the GSL should be expected mostly because of the reduction of sea ice. On the other hand, little changes in the extreme wave climate should be expected as a response to changes in the wind regime over the GSL. For future coastal engineering applications, the GSL wave climate could be evaluated by supposing an ice-free sea to integrate the likely impact of future climate change.

  8. A Regional Comparison of the Long-Term Carbon Dynamics Within Maritime Peat Bogs Along the St. Lawrence North Shore, Northeastern Canada

    NASA Astrophysics Data System (ADS)

    Magnan, G.; Garneau, M.

    2013-12-01

    We have reconstructed the long-term carbon (C) dynamics within maritime bogs from two ecoclimatic regions between the Estuary (Baie-Comeau) and the Gulf of St. Lawrence (Havre-St.-Pierre) in northeastern Canada. The long-term average rates of C accumulation (LORCA) were calculated for eight peatlands. We also compared the Holocene variations in C sequestration between the peatlands to evaluate the influence of climate variability on their long-term C balance. The accumulation/decay processes were linked with changes in vegetation and water table depth. Overall, the LORCA decrease with the age of the peat deposits likely due to constant anoxic decay but they are significantly lower in Havre-St.-Pierre (16-46 g C m-2 yr-1) than in Baie-Comeau (53-68 g C m-2 yr-1). The regional differences in the LORCA reveal a pervasive climatic control on the long-term C balance. Our data suggest that the C accumulation in these bogs was driven by complex interactions between the peat accumulation/decay processes and the climate-mediated water table fluctuations. The higher C accumulation rates in the bogs of Baie-Comeau were promoted by stable ecohydrological conditions whereas the C balance in the bogs of Havre-St.-Pierre was more easily disrupted by past hydroclimatic changes especially during the Neoglacial cooling.

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

    USGS Publications Warehouse

    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.

  10. Late Stage 5 Glacio-isostatic Sea in the St. Lawrence Valley, Canada and United States

    USGS Publications Warehouse

    Occhietti, S.; Balescu, S.; Lamothe, M.; Clet, M.; Cronin, T.; Ferland, P.; Pichet, P.

    1996-01-01

    Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (??18O = -7.1) and from benthic foraminifer and ostracode assemblages. The clay indicates a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000-9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betula and Alnus crispa forest, reached a climatic optimum with Quercus, Corylus, and Abies, and concluded as a Pinus/Picea boreal forest. A corrected infrared stimulated luminescence age of 98,000 ?? 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America. ?? 1996 University of Washington.

  11. Hindcast storm events in the Bering Sea for the St. Lawrence Island and Unalakleet Regions, Alaska

    USGS Publications Warehouse

    Erikson, Li H.; McCall, Robert T.; van Rooijen, Arnold; Norris, Benjamin

    2015-01-01

    This study provides viable estimates of historical storm-induced water levels in the coastal communities of Gambell and Savoonga situated on St. Lawrence Island in the Bering Sea, as well as Unalakleet located at the head of Norton Sound on the western coast of Alaska. Gambell, Savoonga, and Unalakleet are small Native Villages that are regularly impacted by coastal storms but where little quantitative information about these storms exists. The closest continuous water-level gauge is at Nome, located more than 200 kilometers from both St. Lawrence Island and Unalakleet. In this study, storms are identified and quantified using historical atmospheric and sea-ice data and then used as boundary conditions for a suite of numerical models. The work includes storm-surge (temporary rise in water levels due to persistent strong winds and low atmospheric pressures) modeling in the Bering Strait region, as well as modeling of wave runup along specified sections of the coast in Gambell and Unalakleet. Modeled historical water levels are used to develop return periods of storm surge and storm surge plus wave runup at key locations in each community. It is anticipated that the results will fill some of the data void regarding coastal flood data in western Alaska and be used for production of coastal vulnerability maps and community planning efforts.

  12. Late Stage 5 Glacio-isostatic Sea in the St. Lawrence Valley, Canada and United States

    NASA Astrophysics Data System (ADS)

    Occhietti, Serge; Balescu, Sanda; Lamothe, Michel; Clet, Martine; Cronin, Thomas; Ferland, Pierre; Pichet, Pierre

    1996-03-01

    Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (δ 18O = -7.1) and from benthic foraminifer and ostracode assemblages. The clay indicates a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000-9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betulaand Alnus crispaforest, reached a climatic optimum with Quercus, Corylus,and Abies,and concluded as a Pinus/Piceaboreal forest. A corrected infrared stimulated luminescence age of 98,000 ± 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America.

  13. Occurrence of alkylphenol polyethoxylates in the St. Lawrence River and their bioconcentration by mussels (Elliptio complanata).

    PubMed

    Sabik, H; Gagné, F; Blaise, C; Marcogliese, D J; Jeannot, R

    2003-05-01

    A study was conducted in 1999 to determine the occurrence of alkylphenol polyethoxylates in the St. Lawrence River and their bioconcentration by mussels (Elliptio complanata). Concentrations of selected contaminants were measured in surface water, municipal effluent, sediments and mussels. Analyses were performed on 4-tert-octylphenol (4-t-OP), 4-n-nonylphenol (4-n-NP), nonylphenol polyethoxylates (NP(1-16)EO), nonylphenol-mono and di-ethoxycarboxylic acids (NP(1)EC and NP(2)EC), and octylphenol-mono and di-ethoxycarboxylic acids (OP(1)EC and OP(2)EC). Mussels (Elliptio complanata) taken from a reference lake were placed in cages and submerged for 62 days at two sites in the St. Lawrence River, 1.5 km upstream and 5 km downstream of the outfall of a municipal wastewater treatment plant. The results showed that many of the target chemicals were present in all matrices studied: in water, at ppt and ppb levels, and reaching ppm levels in sediments and mussels. Concentrations of these contaminants were higher in matrices sampled at the downstream site than in those drawn at the site upstream of the Montreal effluent outfall, especially in sediments. Likewise, the slight, but not significant, bioconcentration of certain alkylphenol polyethoxylates (AP(n)EO) in the mussels was more noticeable at the downstream site than at the upstream site. PMID:12598000

  14. Key environmental human health issues in the Great Lakes and St. Lawrence River basins

    SciTech Connect

    Johnson, B.L.; Hicks, H.E.; Rosa, C.T. De

    1999-02-01

    In May 1997, an international conference on the effects of the environment on human health in the Great Lakes and St. Lawrence River basins, was held in Montreal, Quebec, Canada. This was the third international conference on this topic sponsored by agencies in the US and Canada. More than 120 platform and poster presentations were given by scientists of different disciplines from the Great lakes region and elsewhere. The presentations represented the most current research findings on the effects of the Great lakes environment on human health. The reports covered environmental contaminant levels of persistent toxic substances (PTSs), routes and pathways of exposure, exposure assessment and human tissue levels of PTSs, human health outcomes, risk communication and assessment, and approaches to scientific collaboration. Reports indicate that levels of contaminants in the Great Lakes and St. Lawrence River basins have generally declined since the 1970s, although certain contaminants have hit a plateau or slightly increased. The findings include elevated body burden levels of contaminants in persons who consume large amounts of some Great Lakes sport fish, developmental deficits and neurologic problems in children of some fish-consuming parents, nervous system dysfunction in adults, and disturbances in reproductive parameters. The findings underscore the need for better public health intervention strategies.

  15. Organochlorine and metal contaminants in traditional foods from St. Lawrence Island, Alaska.

    PubMed

    Welfinger-Smith, Gretchen; Minholz, Judith L; Byrne, Sam; Waghiyi, Vi; Gologergen, Jesse; Kava, Jane; Apatiki, Morgan; Ungott, Eddie; Miller, Pamela K; Arnason, John G; Carpenter, David O

    2011-01-01

    Marine mammals (bowhead whale, walrus, and various seals) constitute the major component of the diet of the Yupik people of St. Lawrence Island, Alaska. St. Lawrence Island residents have higher serum concentrations of polychlorinated biphenyls (PCB) than in the general U.S. population. In order to determine potential sources, traditional food samples were collected from 2004 to 2009 and analyzed for PCBs, three chlorinated pesticides, and seven heavy metals (mercury, copper, zinc, arsenic, selenium, cadmium, and lead). Concentrations of PCB in rendered oils (193-421 ppb) and blubber (73-317 ppb) from all marine mammal samples were at levels that trigger advisories for severely restricted consumption, using U.S. Environmental Protection Agency (EPA) fish consumption advisories. Concentrations of pesticides were lower, but were still elevated. The highest PCB concentrations were found in polar bear (445 ppb) and the lowest in reindeer adipose tissue (2 ppb). Marine mammal and polar bear meat in general have PCB concentrations that were 1-5% of those in rendered oils or adipose tissue. PCB concentrations in organs were higher than meat. Concentrations of metals in oils and meats from all species were relatively low, but increased levels of mercury, cadmium, copper, and zinc were present in some liver and kidney samples. Mercury and arsenic were found in lipid-rich samples, indicating organometals. These results show that the source of the elevated concentrations of these contaminants in the Yupik population is primarily from consumption of marine mammal blubber and rendered oils. PMID:21797772

  16. Middle pleistocene mollusks from St. Lawrence Island and their significance for the paleo-oceanography of the Bering Sea

    USGS Publications Warehouse

    Hopkins, D.M.; Rowland, R.W.; Patton, W.W., Jr.

    1972-01-01

    Drift, evidently of Illinoian age, was deposited on St. Lawrence Island at the margin of an ice cap that covered the highlands of the Chukotka Peninsula of Siberia and spread far eastward on the continental shelf of northern Bering Sea. Underlying the drift on the northwestward part of the island are mollusk-bearing beds deposited during the Kotzebuan Transgression. A comparison of mollusk faunas from St. Lawrence Island, Chukotka Peninsula, and Kotzebue Sound suggests that the present northward flow through Bering and Anadyr Straits was reversed during the Kotzebuan Transgression. Cold arctic water penetrated southward and southwestward bringing an arctic fauna to the Gulf of Anadyr. Warmer Pacific water probably entered eastern Bering Sea, passed eastward and northeastward around eastern and northern St. Lawrence Island, and then became entrained in the southward currents that passed through Anadyr Strait. ?? 1972.

  17. Crustal strain rates and seismic hazard from seismicity and GPS measurements along the St Lawrence Valley, Quebec

    NASA Astrophysics Data System (ADS)

    Mazzotti, S.; Henton, J.; Adams, J.

    2004-05-01

    The St Lawrence Valley, Quebec, presents one of the largest concentration of earthquakes in eastern North America. Background seismicity extends over 900 km from the Gulf of St Lawrence to Montreal following the Paleozoic Iapetan Rift system. Two main seismic zones are defined along this trend: Charlevoix, the most active in eastern Canada and the locus of at least five M6+ earthquakes in the last 350 years; and Lower St Lawrence, where the largest known earthquakes are about M5. Integration of earthquake statistics in both zones indicates that the equivalent seismic deformation rates are 1.0 +/- 0.5 mm/yr and 0.2 +/- 0.3 mm/yr, respectively. Based on high-precision GPS measurements at 16 sites surrounding the St Lawrence Valley, we estimate the current rate of crustal strain across both the Charlevoix and Lower St Lawrence seismic zones. Our GPS results are based on 3-4 campaign occupations over the last 7-9 years. On a regional scale, horizontal strain rates are 0.5-2 nanostrain per year of roughly NNW-SSE shortening. This strain pattern agrees well with earthquake focal mechanisms. Horizontal velocity vectors on both sides of the St Lawrence River suggest that this shortening corresponds to a maximum convergence of 0.5 +/- 0.5 mm/yr between the north and south shores, in general agreement with the rate from earthquake statistics. Assuming that seismicity in Charlevoix follows typical b-value statistics, our GPS results constrain the maximum magnitude of large earthquakes to be less than or equal to M7.6. Alternatively these strain rates are equivalent to one characteristic M7 earthquake per ~170 years.

  18. Impact of climate change on the hydrology of St. Lawrence tributaries

    NASA Astrophysics Data System (ADS)

    Boyer, Claudine; Chaumont, Diane; Chartier, Isabelle; Roy, Andr G.

    2010-04-01

    SummaryChanges in temperature and precipitation projected for the next century will induce important modifications into the hydrological regimes of the St. Lawrence tributaries (Quebec, Canada). The temperature increase anticipated during the winter and spring seasons will affect precipitation phase and consequently the snow/precipitation ratio and the water volume stored into snow cover. The impact on northern river hydrology and geomorphology will be significant. In this study we aim to assess the magnitude of the hydrological alteration associated with climate change; to model the projected temporal shift in the occurrence of winter/spring center-volume date; to assess the sensitivity of the winter/spring center-volume date to changes in climatic variables and to examine the latitudinal component of the projected changes through the use of five watersheds on both shores of the St. Lawrence. The study emphasizes changes in the winter and spring seasons. Projected river discharges for the next century were generated with the hydrological model HSAMI run with six climate series projections. Three General Circulation Models (HadCM3, CSIRO-Mk2 and ECHAM4) and two greenhouse gas emissions scenarios (A2 and B2) were used to create a range of plausible scenarios. The projected daily climate series were produced using the historical data of a reference period (1961-1990) with a perturbation factor equivalent to the monthly mean difference (temperature and precipitation) between a GCM in the future for three 30 year horizons (2010-2039, 2040-2069; 2070-2099) and the reference period. These climate projections represent an uncertainty envelope for the projected hydrologic data. Despite the differences due mainly to the GCM used, most of the hydrological simulations projected an increase in winter discharges and a decrease in spring discharges. The center-volume date is expected to be in advance by 22-34 days depending on the latitude of the watershed. The increase in mean temperature with the simultaneous decrease of the snow/precipitation ratio during the winter and spring period explain a large part of the projected hydrological changes. The latitude of the river governed the timing of occurrence of the maximum change (sooner for tributaries located south) and the duration of the period affected by marked changes in the temporal distribution of discharge (longer time scale for rivers located at higher latitudes). Higher winter discharges are expected to have an important geomorphological impact mostly because they may occur under ice-cover conditions. Lower spring discharges may promote sedimentation into the tributary and at their confluence with the St. Lawrence River. The combined effects of modifications in river hydrology and geomorphological processes will likely impact riparian ecosystems.

  19. Physical growth of St. Lawrence Island Eskimos: body size, proportion, and composition.

    PubMed

    Johnston, F E; Laughlin, W S; Harper, A B; Ensroth, A E

    1982-08-01

    Growth patterns of body size, proportion, and composition were analyzed in 57 male and 56 female Eskimos from St. Lawrence Island in the Bering Sea, ranging in age from 1.23 through 19.82 years. Age-groups means for whites and blacks of the U.S. Health Examination Survey served as reference data. Relative to HES data, the Eskimo sample were shorter with lower values for leg length, while there were no differences from the reference values for sitting height. The Eskimos also had higher values of Quetelet's Index, the sitting height/height ratio, and the upper arm muscle circumference, while there were no differences in body weight or triceps skinfold thickness. Differences from the reference data were more pronounced in males than in females. The growth patterns for size and body proportion are in conformity with known relationships between morphology and climate. PMID:7124933

  20. High-resolution 3D modelling of planktonic production in the Gulf of St. Lawrence, Canada

    NASA Astrophysics Data System (ADS)

    Le Fouest, V.; Zakardjian, B.; Saucier, F.-J.; Starr, M.

    2003-04-01

    We present first results of a coupled 3D high resolution ecosystem/physical model that was developed to study the effects of the complex physical environment of the Gulf of St. Lawrence on the seasonal pattern of planktonic production. The coupled model includes both simplified herbivorous and microbial food chains characteristic of bloom and post-bloom conditions respectively, as generally observed in temperate and sub-arctic coastal waters. It is driven by a 3-D high resolution primitive equations ice/ocean regional model with realistic tidal, atmospheric and hydrologic forcing for the 1997 year. The model produces a coherent seasonal primary production cycle that compares well with data from the Atlantic Zonal Monitoring Program. These first results highlight (i) the fundamental role of ice for the timing of the vernal bloom and (ii) the strong influence of mesoscale processes induced by wind and fresh water discharge on planctonic production during summer and autumn.

  1. Early Adoption Technology Performance Impact: AIS on the St. Lawrence Seaway

    NASA Astrophysics Data System (ADS)

    Grabowski, Martha; Dhami, Hemil

    2005-01-01

    An Automatic Identification System (AIS) was implemented in the St. Lawrence Seaway during 2003. This paper reports the results of a trial conducted pre- and post-AIS implementation to examine the impact of AIS adoption in a safety-critical system. Analysis of the impact on three types of operators, ship's masters, mates and shore-based traffic management system operators showed that overall AIS significantly improved voyage plan monitoring, contributed to improved monitoring vigilance and offered significant aid to decision making. Recommendations include follow-on studies to include a steady state evaluation of the technology impact once the system is mature and a broadening of the pool of subjects to include a less experienced, more international and less well educated group of operators.

  2. Dynamic mass balance model for mercury in the St. Lawrence River near Cornwall, Ontario, Canada.

    PubMed

    Lessard, Charlotte R; Poulain, Alexandre J; Ridal, Jeffrey J; Blais, Jules M

    2014-12-01

    A dynamic mass balance model was developed for the St. Lawrence River near Cornwall, Ontario that predicts and hindcasts mercury concentrations and fluxes in three forms, elemental Hg (Hg(0)), divalent mercury (Hg(2+)), and methyl mercury (MeHg), in a six compartment environment (air, water, porewater, sediment, periphyton, and benthic invertebrates). Our objective was to construct a dynamic mass balance model for mercury in the St. Lawrence River near Cornwall, Ontario based on the framework and results of a steady-state mass balance model developed previously for this site. The second objective was to estimate industrial mercury emissions based on mercury residues deposited in sediments prior to 1970, the year when regulations were implemented to reduce mercury pollution in the environment. We compiled mercury concentrations, fluxes, and transformation rates from previous studies completed in this section of the river (area of approximately 100km(2)) to develop the model. Estimated mercury concentrations in all media were similar to measured data (R(2)=0.99), with only minor exceptions, providing a satisfactory overall description of the mercury loadings and transformation rates of the different mercury species. The estimated historical emissions prior to 1970 from local industries along the Cornwall waterfront were approximately 400kgyear(-1). A storm sewer discharge of 5000m(3)/day resulted in a significant increase in mercury concentrations, particularly in sediment (617ngg(-1) to 624ngg(-1); p=0.004). Model results suggest that discharges of mercury from sources such as local industries and storm sewers have an impact on mercury in media such as sediment and water. This model should provide a basis for predicting and hindcasting mercury concentrations in other river environments as well, because it considers three distinct forms of mercury, and contains environmental media common to all rivers, including some (e.g. periphyton) not typically included in previous mercury models. PMID:25217751

  3. Time Series Analysis of Water Level and Temperature in the St Louis River Estuary

    EPA Science Inventory

    Pressure and temperature loggers were deployed at 9 sites in the St Louis River estuary between 6/23 10/31 2011. A reference sensor was place on the shore to correct pressure data. Sensors were paced at <1 m depth in Allouez Bay, Superior Bay, near Hearding Island, WLSSD Bay, th...

  4. The faucet snail (Bithynia tentaculata) invades the St. Louis River Estuary

    EPA Science Inventory

    The European-origin faucet snail (Bithynia tentaculata) now numbers among the aquatic invasive species present in the St. Louis River Estuary. This snail has been in the lower Great Lakes since the early 20th century but is new to the Lake Superior basin. We found faucet snails...

  5. Distribution of submerged aquatic vegetation in the St. Louis River estuary: Maps and models

    EPA Science Inventory

    In late summer of 2011 and 2012 we used echo-sounding gear to map the distribution of submerged aquatic vegetation (SAV) in the St. Louis River Estuary (SLRE). From these data we produced maps of SAV distribution and we created logistic models to predict the probability of occurr...

  6. Habitat use and trophic position effects on contaminant bioaccumulation in St. Louis River Estuary fishes

    EPA Science Inventory

    The objective of our study was to determine the relationship between fish tissue stable isotope composition and total mercury or polychlorinated biphenyl (PCB) concentrations in the St. Louis River estuary food web. We sampled two resident fishes, Yellow Perch (Perca flavescens) ...

  7. 33 CFR 207.610 - St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration, and navigation of the harbor...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration, and navigation of the harbor and U.S. breakwater. 207.610 Section 207... NAVIGATION REGULATIONS § 207.610 St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration,...

  8. Ground-water quality and data on wells and springs in Pennsylvania; Volume I, Ohio and St. Lawrence River basins

    USGS Publications Warehouse

    Koester, Harry E.; Miller, Denise R.

    1980-01-01

    Volume I of the Groundwater Quality and Data on Wells and Springs in Pennsylvania presents groundwater quality and physical data on about 1,200 well and spring sites in the Ohio and St. Lawrence River basins. Locations are shown on site-location maps derived from the hydrologic unit map. Codes showing the geologic age and aquifer are provided. (USGS)

  9. 78 FR 50136 - iVoice, Inc., Protectus Medical Devices, Inc., and St. Lawrence Energy Corp.; Order of Suspension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION iVoice, Inc., Protectus Medical Devices, Inc., and St. Lawrence Energy Corp.; Order of Suspension of Trading August 14, 2013. It appears to the Securities and Exchange Commission that there is a lack of current and accurate...

  10. 78 FR 71037 - St. Lawrence & Atlantic Railroad Company-Discontinuance of Service Exemption-in Cumberland County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ...--in Cumberland County, Me. On November 8, 2013, St. Lawrence & Atlantic Railroad Company (SLR) filed... rail line, owned by the State of Maine, between milepost 1.74 near Deering, Cumberland County, Me., and milepost 25.97 at the town line between New Gloucester, Cumberland County and Auburn, Androscoggin...

  11. Isotopic monitoring (2H, 18O) of the St. Lawrence and Ottawa rivers between 1997 and 2003- Links with interannual climatic variability and hydrological processes in their catchment basins

    NASA Astrophysics Data System (ADS)

    Myre, A.; Hillaire-Marcel, C.

    2004-05-01

    This study based on a water isotope (18O and 2H) monitoring of the St. Lawrence and Ottawa rivers (Canada) is a contribution to the international IAEA project: Isotopes tracing of hydrologic processes in large river basins [Gibson et al., 2002. EOS 83: 613 et p.]. Sampling of the St. Lawrence and Ottawa river waters started in 1997, on a biweekly to weekly basis. Monitoring stations are located at Montreal (i.e., at the outlet of the Great Lakes), Quebec City (the estuary of the St. Lawrence) and at the Carillon hydroelectric dam, near the outlet of a major tributary, the Ottawa River into the St. Lawrence itself. The goal of the study was to examine the seasonal and interannual variability of isotopic signatures of the St. Lawrence and Ottawa rivers, in relation notably with interannual climatic variations, and seasonal hydrologic processes in the watershed (summer evaporation, snowmelt, transit time of precipitation signals into runoff). Waters sampled at the three stations depict distinct isotopic compositions. At Montreal, relatively stable isotopic composition are observed with a mean weighted annual value of -54 % for 2H and -7.1 % for 18O. The Ottawa River water at Carillon also displays stable isotopic compositions but much lighter values (weighted mean annual values: -80 % for 2H and -10.8 % for 18O). Finally, isotopic compositions at Quebec City are intermediate between those of Montreal and Carillon, but show a much larger variability. They reflect mixing between the heavy isotope enriched Great Lakes water, the lighter water from the Ottawa River, and highly variable inputs from smaller tributaries (from the Laurentides and Appalachian mountains). The mean weighted isotopic compositions at Quebec City are -65 % and -8.6 %, respectively for 2H and 18O). Evaporative enrichment, in particular during low water level episodes, seem to be more important in the Ottawa River catchment than in the Great Lakes basin, based on a comparison of isotopic clusters at Montreal and Carillon (figure 1). Relatively strongly correlated relationships are observed between isotopic compositions at the estuary of the St. Lawrence River (Quebec) and hydrologic variables such as water discharge. The best fit follows the equation : 2HQUEBEC = -1.9E-03 * QQUEBEC - 41.9, R2= 0.59. Such a relationship leads us to conclude that some properties of the regional hydrology can be relatively well described by stable isotope systematics. In contradiction, air temperatures are not well correlated with isotopic signatures partly because of lag times between them in relation to transit time of precipitation signal into runoff. A comparison of isotopic values in precipitation to those of runoff gives an estimate of the mean transfer time of water from the catchment to the river estuary. For summer heavy isotope enriched, but scarcer precipitation, a transit time of approximately 3 months is observed, whereas in winter, it can be as long as 4 to 5 months due to the residence time of winter precipitation in the snowcover. The assessment of the interannual variability of the St. Lawrence River isotopic system will require a better estimate of the isotopic inprint from small tributaries (that drain isotopically buffered ground waters, particularly in winter). Data are presently at processing stage.

  12. Genetics and shell morphometrics of assimineids (Mollusca, Caenogastropoda, Truncatelloidea) in the St Lucia Estuary, South Africa

    PubMed Central

    Miranda, Nelson A. F.; van Rooyen, Ryan; MacDonald, Angus; Ponder, Winston; Perissinotto, Renzo

    2014-01-01

    Abstract The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI) and nuclear (28S) DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named “Assiminea” aff. capensis (Sowerby). These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted. PMID:25061361

  13. Lake sturgeon spawning on artificial habitat in the St Lawrence River

    USGS Publications Warehouse

    Johnson, J.H.; LaPan, S.R.; Klindt, R.M.; Schiavone, A.

    2006-01-01

    In 1996, lake sturgeon (Acipenser fulvescens) spawning was documented for the third consecutive year on an artificially placed gravel bed in the St Lawrence River. Two distinct spawning periods were observed in 1996. Spawning initially commenced on 17 June, when water temperature reached 15??C. A second spawning event was documented from 28 June to 1 July (16??C). Sturgeon egg densities were monitored in three transects on egg trays, on the gravel surface, and within interstitial spaces in the gravel. Counts of developing eggs in the gravel bed during both spawning periods were used to estimate a total of 275000 eggs on the study area (0.075 ha). Average egg density was highest in the transect with the highest water velocities. Lake sturgeon fry were first observed in the gravel on 24 June (15.5??C), and first emergence from the gravel was documented on 28 June. Hatching following the second spawning event commenced on 3 July. Based on assessment of average embryo viability (61.6%) and egg-to-emergent fry survival (17.6%) an estimate of about 171000 sturgeon eggs hatched, producing over 49000 emergent fry. Current velocity, substrate particle size, depth of substrate, and maintenance of sediment-free interstitial spaces are important considerations in planning future spawning habitat enhancement projects. ?? Journal compilation 2006 Blackwell Verlag, Berlin.

  14. Giardia and Cryptosporidium in harp and hooded seals from the Gulf of St. Lawrence, Canada.

    PubMed

    Appelbee, A J; Thompson, R C A; Measures, L M; Olson, M E

    2010-10-11

    Giardia and Cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial wildlife species (mammals, reptiles and birds). Few surveys for Giardia and Cryptosporidium in marine wildlife species, such as pinnipeds, have been reported. The objective of this study was to determine the prevalence and genotype of Giardia and Cryptosporidium in two species of pinnipeds, harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata), from the Gulf of St. Lawrence, Canada. Faecal samples were collected from pup and adult seals and examined for the presence of cysts of Giardia and oocysts of Cryptosporidium using microscopy and immunofluorescent staining. Tissues from the small intestine of adult seals were also collected and examined for infections using the polymerase chain reaction (PCR) technique. Giardia cysts were found in the faeces of 42% (16/38) of adult harp seals, but in none of the harp seal pups (0/20). Although Giardia cysts were not detected in faeces of adult hooded seals (0/10) using microscopy, 80% tested positive for Giardia using PCR of intestinal tissue indicative of a true replicating infection. Both harp and hooded seals harboured infections with the zoonotic strain, Giardia duodenalis Assemblage A, as determined using a nested-PCR technique to amplify a small subunit ribosomal (SSU-rRNA) gene of Giardia. Cryptosporidium was not detected by microscopy, nor using the PCR technique on intestinal tissues from any of the 68 seals examined. PMID:20594649

  15. Late Quaternary history of the southwestern St. Lawrence Lowlands and adjacent Adirondack Highlands

    SciTech Connect

    Pair, D.L. . Dept. of Geology)

    1993-03-01

    The reconstruction of Late Wisconsinan ice retreat, proglacial lakes, and Champlain Sea history from the northwest Adirondack slope and adjacent St. Lawrence Lowlands is critical to the synthesis of a regional picture of deglacial events in the eastern Great Lakes region. Unfortunately, these same areas are well known for their limited exposures, landforms covered by thick forest, large tracts of land inaccessible to detailed field mapping, and the overall paucity of glacial materials preserved on upland surfaces. Despite these limitations, a model which utilizes multiple and field-truthed evidence has been used to designate areas where ice border deposits indicate a substantial recessional position. It employs the following criteria in this analysis: sedimentology and morphostratigraphy of morainal landform segments and related sediments; orientation and continuity of ice border drainage channels; and the relationship of ice borders and drainage systems to well documented local and regional water bodies which accompanied ice retreat. The results of this approach have provided a unique regional picture of deglaciation. Despite the inherent limitations of working in upland areas to reconstruct glacial events, detailed morphostratigraphic correlations based on multiple lines of evidence can yield important information. The positions of five former ice borders have been reconstructed from the available data. These ice margins correspond closely with those documented previously by others adjoining areas. This type of study, utilizing multiple and field-truthed lines of evidence, constitutes a tangible step towards understanding the nature and history of ice retreat along this portion of the Laurentide Ice Sheet.

  16. Novel brominated flame retardants and dechloranes in three fish species from the St. Lawrence River, Canada.

    PubMed

    Houde, Magali; Berryman, David; de Lafontaine, Yves; Verreault, Jonathan

    2014-05-01

    Restrictions in the utilization of polybrominated diphenyl ether (PBDE) mixtures have led to the increased usage of alternative flame retardant additives in a wide range of commercial applications. The present study examined the occurrence of established and emerging flame retardants (FRs) in fish from a densely-populated urbanized sector of the St. Lawrence River (Montreal, Quebec, Canada). Thirty-eight PBDE congeners and sixteen emerging FRs were determined in fish belonging to three predatory species (yellow perch, northern pike, and muskellunge). The ∑PBDE in fish were up to 24,115 ng/g lipid weight (l.w.) in the apex predator muskellunge. Twelve emerging FRs including bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP), pentabromoethylbenzene (PBEB), Dechlorane Plus (anti and syn), dechloranes (Dec) 602, Dec 604, Dec 604 Compound B (Dec 604 CB), and Chlordene Plus (CP) were detected (>0.01 ng/gl.w.) in the liver of muskellunge and northern pike but not in yellow perch homogenates. This is the first report of Dec 604 CB in any fish species. The bioavailability of these FRs in human-impacted aquatic ecosystems warrants further environmental assessment and toxicity testing. PMID:24534698

  17. Mapping ecosystem services in the St. Louis River Estuary

    EPA Science Inventory

    Sustainable management of ecosystems for the perpetual flow of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching U.S. EPA goal of ...

  18. Mapping ecosystem services in the St. Louis River estuary (presentation)

    EPA Science Inventory

    Management of ecosystems for sustainable provision of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching EPA goal of community sust...

  19. Three-dimensional modeling of hydrodynamic processes in the St. Lucie Estuary

    NASA Astrophysics Data System (ADS)

    Ji, Zhen-Gang; Hu, Guangdou; Shen, Jian; Wan, Yongshan

    2007-06-01

    Comparing with the studies on large estuarine systems, such as the Chesapeake Bay and the San Francisco Bay, the processes of stratification and transport in small and shallow estuaries are relatively less studied. The St. Lucie Estuary (SLE) is a riverine estuary located on the east coast of south Florida. It is small and shallow, with mean depth of 2.4 m. To study the estuarine processes in the SLE, a hydrodynamic model was developed based on the Environmental Fluid Dynamics Code (EFDC) [Hamrick, J.M., 1992. A three-dimensional environmental fluid dynamics computer code: theoretical and computational aspects. The College of William and Mary, Virginia Institute of Marine Science, Special Report 317, 63 pp.]. The model was calibrated and verified using observational data obtained in 1999 and 2000, respectively. The model variables used for model data-comparisons are water elevation, velocity, temperature, and salinity. The model is then applied to study the hydrodynamic processes in the SLE. It is found that freshwater inflow plays a major role in the stratification and net flushing of the SLE. Stratification generally increases with freshwater inflow. But when the inflow is persistently large for a relatively long period, the estuary can suddenly change from very stratified to well mixed within a few tidal cycles and the stratification collapses. This finding suggests that large and persistent freshwater inflows do not always increase estuarine stratification. Instead, it may cause the stratification to collapse within a short period of time. In addition to gauged tributaries, ungauged lateral inflows can also be important to small and shallow estuaries like the SLE. Although small individually, the ungauged streams and surface runoffs can be a significant portion of the total inflow and affect salinity distribution significantly. Flushing time affects a wide range of hydrodynamic and water quality processes in the estuary. The model results indicate that commonly used formulas, such as the tidal prism formula and the Knudsen formula, may significantly underestimate the flushing time.

  20. Year-class formation of upper St. Lawrence River northern pike

    USGS Publications Warehouse

    Smith, B.M.; Farrell, J.M.; Underwood, H.B.; Smith, S.J.

    2007-01-01

    Variables associated with year-class formation in upper St. Lawrence River northern pike Esox lucius were examined to explore population trends. A partial least-squares (PLS) regression model (PLS 1) was used to relate a year-class strength index (YCSI; 1974-1997) to explanatory variables associated with spawning and nursery areas (seasonal water level and temperature and their variability, number of ice days, and last day of ice presence). A second model (PLS 2) incorporated four additional ecological variables: potential predators (abundance of double-crested cormorants Phalacrocorax auritus and yellow perch Perca flavescens), female northern pike biomass (as a measure of stock-recruitment effects), and total phosphorus (productivity). Trends in adult northern pike catch revealed a decline (1981-2005), and year-class strength was positively related to catch per unit effort (CPUE; R2 = 0.58). The YCSI exceeded the 23-year mean in only 2 of the last 10 years. Cyclic patterns in the YCSI time series (along with strong year-classes every 4-6 years) were apparent, as was a dampening effect of amplitude beginning around 1990. The PLS 1 model explained over 50% of variation in both explanatory variables and the dependent variable, YCSI first-order moving-average residuals. Variables retained (N = 10; Wold's statistic ??? 0.8) included negative YCSI associations with high summer water levels, high variability in spring and fall water levels, and variability in fall water temperature. The YCSI exhibited positive associations with high spring, summer, and fall water temperature, variability in spring temperature, and high winter and spring water level. The PLS 2 model led to positive YCSI associations with phosphorus and yellow perch CPUE and a negative correlation with double-crested cormorant abundance. Environmental variables (water level and temperature) are hypothesized to regulate northern pike YCSI cycles, and dampening in YCSI magnitude may be related to a combination of factors, including wetland habitat changes, reduced nutrient loading, and increased predation by double-crested cormorants. ?? Copyright by the American Fisheries Society 2007.

  1. Study on subtidal circulation and variability in the Gulf of St. Lawrence, Scotian Shelf, and Gulf of Maine using a nested-grid shelf circulation model

    NASA Astrophysics Data System (ADS)

    Urrego-Blanco, Jorge; Sheng, Jinyu

    2014-03-01

    This paper examines the subtidal circulation and associated variability in the Gulf of St. Lawrence, the Scotian Shelf, and the Gulf of Maine (GSL-SS-GOM) in 1988-2004 based on results produced by a nested-grid shelf circulation model. The model has a fine-resolution child model (˜ (1/12)°) embedded inside a coarse-resolution parent model (˜ (1/4)°) of the northwest Atlantic. The combination of the semi-prognostic method and the spectral nudging method is used to reduce the model seasonal bias and drift. The child model reproduces the general features of the observed circulation and hydrography over the study region during the study period. The child model results demonstrate that the time-mean circulation in the GSL is affected by the time-mean atmospheric forcing and inflow through the Strait of Belle Isle. The temporal variability in atmospheric forcing affects the outflow through western Cabot Strait, which in turn affects the transport of the Nova Scotian Current and the gulf-wide cyclonic circulation in the GOM. The simulated seasonal variability of salinity in the top 30 m of the GSL-SS-GOM is mainly affected by the equatorward advection of low-salinity waters from the lower St. Lawrence Estuary to the GOM through the Scotian Shelf. The simulated intraseasonal variability of circulation in the GSL is affected by the variability in the estuarine circulation in response to the temporal variability in atmospheric forcing. On the Scotian Shelf, the intraseasonal variability is mainly driven by the variability of wind forcing and mesoscale and nonlinear dynamics over the shelf break and slope region. The interannual variability in the simulated temperature and salinity are spatially coherent in the intermediate waters in the GSL, which is caused partially by the local response to atmospheric variability and partially by variabilities over the southern Newfoundland Shelf that enter the GSL through the eastern Cabot Strait. By comparison, on the Scotian Shelf, the interannual variability of simulated circulation is affected by anomalies produced by the nonlinear dynamics which are advected equatorwards by the shelf break jet.

  2. Reconnaissance investigation of high-calcium marble in the Beaver Creek area, St. Lawrence County, New York

    USGS Publications Warehouse

    Brown, C. Ervin

    1978-01-01

    Three belts of marble of the Grenville Series were mapped in the Beaver Creek drainage basin, St. Lawrence County, N.Y. One of these, on the west side of Beaver Creek, consists of coarsely crystalline pure calcitic marble that occurs in a zone at least 10 by 0.8 km in extent. Samples of marble show CaCO3 content to be greater than 93 percent, and some samples contain greater than 96 percent, and only small amounts of MgO and Fe203 are present. Marble in two other belts to the east of Beaver Creek are variable in composition, but locally have high content of calcium carbonate material. The marble deposit west of Beaver Creek has a chemical composition favorable for specialized chemical, industrial, and metallurgical uses. Another favorable aspect of the deposit is its proximity to inexpensive water transportation on the St. Lawrence Seaway only 27.5 km away by road, at Ogdensburg, N.Y.

  3. Seasonal versus synoptic variability in planktonic production in a high-latitude marginal sea: The Gulf of St. Lawrence (Canada)

    NASA Astrophysics Data System (ADS)

    Le Fouest, V.; Zakardjian, B.; Saucier, F. J.; Starr, M.

    2005-09-01

    The Gulf of St. Lawrence (Canada) is a subarctic marginal sea characterized by highly variable hydrodynamic conditions that generate a spatial heterogeneity in the marine production. A better understanding of physical-biological linkages is needed to improve our ability to evaluate the effects of climate variability and change on the gulf's planktonic production. We develop a three-dimensional (3-D) eddy permitting resolution physical-biological coupled model of plankton dynamics in the Gulf of St. Lawrence. The planktonic ecosystem model accounts for the competition between simplified herbivorous and microbial food webs that characterize bloom and post-bloom conditions, respectively, as generally observed in temperate and subarctic coastal waters. It is driven by a fully prognostic 3-D sea ice-ocean model with realistic tidal, atmospheric, and hydrological forcing. The simulation shows a consistent seasonal primary production cycle, and highlights the importance of local sea ice dynamics for the timing of the vernal bloom and the strong influence of the mesoscale circulation on planktonic production patterns at subregional scales.

  4. Contrasting changes between the northern and southern Gulf of St. Lawrence ecosystems associated with the collapse of groundfish stocks

    NASA Astrophysics Data System (ADS)

    Morissette, Lyne; Castonguay, Martin; Savenkoff, Claude; Swain, Douglas P.; Chabot, Denis; Bourdages, Hugo; Hammill, Mike O.; Mark Hanson, J.

    2009-10-01

    In order to have a global view of ecosystem changes associated with the collapse of groundfish species in the Gulf of St. Lawrence during the early 1990s, Ecopath mass-balance models were constructed incorporating uncertainty in the input data. These models covered two ecosystems (northern and southern Gulf of St. Lawrence; NAFO divisions 4RS and 4T), and two time periods (before the collapse, in the mid-1980s, and after it, in the mid-1990s). Our analyses revealed that the ecosystem structure shifted dramatically from one previously dominated by piscivorous groundfish and small-bodied forage species during the mid-1980s to one now dominated only by small-bodied pelagic species during the mid-1990s in both southern and northern Gulf. The species structure in the northern Gulf versus southern Gulf was different, which may explain why these two ecosystems did not recover the same way from the collapse in the early 1990s. Productivity declined in the northern Gulf after the collapse but increased in the southern Gulf. The collapse of groundfish stocks resulted in declines in the mean trophic level of the landings in both the northern and the southern Gulf. Even though fishing mortality was then intentionally reduced, this part of the total mortality was taken up by predation. The temporal changes in the internal structure of both ecosystems are reflected in their overall emergent properties.

  5. Induction of gene responses in St. Lawrence River northern pike (Esox lucius) environmentally exposed to perfluorinated compounds.

    PubMed

    Houde, Magali; Douville, Mlanie; Despatie, Simon-Pierre; De Silva, Amila O; Spencer, Christine

    2013-08-01

    Municipal waste water effluents (MWWEs) are important sources of chemical contamination for aquatic environments. This study investigated the presence and effects of perfluorinated compounds (PFCs) in environmentally exposed northern pike (Esox lucius) collected upstream and downstream a major municipal waste water treatment plant (WWTP) in the St. Lawrence River, Canada. Twelve PFCs, including the newly detected perfluoroethylcyclohexane sulfonate (PFECHS), were quantified in fish muscle, liver, and plasma. Additionally, the expression of eight genes and the activity of three biomarkers were analyzed in fish tissues at both sites. Mean ?PFC concentration in fish plasma collected upstream the WWTP was 185ng/g w.w. compared to 545ng/g w.w. downstream the point of release. PFECHS was quantified for the first time in St. Lawrence River fish (mean plasma concentration in MWWE fish: 5.074.72ng/g w.w.). Results of transcriptomic responses were tissue-specific and indicated significant up-regulation for metallothionein (MT) in blood and MT, glutathion-S-transferase (GST), superoxide dismutase (SOD), and cytochromes P450 1A1 (CYP1A1) in gill tissue of fish collected in the MWWE suggesting greater stress responses for organisms at this location. Significant relationships were found between vitellogenin (Vtg) gene expression in liver, Vtg activity in plasma and perfluorotridecanoic acid (PFTrA), perfluorotetradecanoic acid (PFTeA), and perfluorodecane sulfonate (PFDS) plasma concentrations. The possible endocrine effects of these PFCs should be further investigated. PMID:23453599

  6. Forecasting the Major Influences of Predation and Environment on Cod Recovery in the Northern Gulf of St. Lawrence

    PubMed Central

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E.; Hammill, Mike O.

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010–2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry. PMID:24523852

  7. Forecasting the major influences of predation and environment on cod recovery in the northern Gulf of St. Lawrence.

    PubMed

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E; Hammill, Mike O

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010-2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry. PMID:24523852

  8. Strike-slip interpretation of basin-bounding faults of the St. Lawrence lowlands basin the Quebec City area, Canada

    SciTech Connect

    Shaw, B.R. , Houston, TX )

    1993-05-01

    Traditional structural interpretations of faults identified in the autochthonous, Ordovician platform rocks of the St. Lawrence Lowlands basin of Quebec, Canada, assert that the primary sense of faulting is normal, extensional, and dip-slip in motion. Interpretation of field observations such as the offset of facies boundaries in outcrop, fault surface features, fracture patterns, and fault volume considerations lead directly to difficulties with a mobile crustal bulge model for normal faulting. Newly reprocessed seismic data and well-log correlations support this interpretation and indicate a need for a different model for the deformation of the platform margin. A left-lateral, basement-involved wrench system resolves stratigraphic discordances across fault zones, contradictions in the observed geometry of hanging-wall blocks, problems concerning timing of tectonic events, and the difficulty of using extensional deformation models in a compressional setting. This reinterpretation places the timing of the platform faulting just prior to the arrival of the Taconic thrust sheet. The lateral offset of subsurface and surface depositional facies, fault trace features, well correlations, and seismic expressions document approximately 60 km of left-lateral strike-slip motion in the St. Lawrence Lowlands basin. 30 refs., 14 figs., 1 tab.

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

    PubMed

    Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

    2006-02-01

    The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios. PMID:16502038

  10. A decade of aquatic invasive species (AIS) early detection method development in the St. Louis River estuary

    EPA Science Inventory

    As an invasion prone location, the St. Louis River Estuary (SLRE) has been a case study for ongoing research to develop the framework for a practical Great Lakes monitoring network for early detection of aquatic invasive species (AIS). Early detection, however, necessitates findi...

  11. Shoreline Classification of the St. Louis River Estuary using Geographic Information Systems and Standard Landuse/Landcover Data Sets

    EPA Science Inventory

    The St. Louis River Estuary (SLRE) shoreline is ~300 km in length and borders MN and WI from the MN highway 23 downstream to Lake Superior. The shoreline is a complex and diverse mixture of many features from industrial docks and slips in the lower SLRE to complex wetlands and na...

  12. A survey of the St. Louis River estuary with emphasis on non-indigenous species and habitat structure

    EPA Science Inventory

    As part of a larger study to develop a monitoring network for aquatic non-indigenous species (NIS), a comprehensive multi-gear survey of larval fish and macroinvertebrates in the St. Louis River estuary was conducted during summer 2012. A total of 139 larval fish samples and 118...

  13. Mesozoic fault reactivation along the St. Lawrence Rift System as constrained by (U-Th/He) thermochronology

    NASA Astrophysics Data System (ADS)

    Bouvier, L.; Pinti, D. L.; Tremblay, A.; Minarik, W. G.; Roden-Tice, M. K.; Pik, R.

    2011-12-01

    The Saint Lawrence Rift System (SLRS) is a half-graben, extending for 1000 km along St. Lawrence River valley. Late Proterozoic-Early Paleozoic faults of the graben form the contact with the metamorphic Grenvillian basement to the northwest and extend under the Paleozoic sedimentary sequences of the St. Lawrence Lowlands to the southeast. The SLRS is the second most seismically active area in Canada, but the causes of this activity remain unclear. Reactivation of the SLRS is believed to have occurred along Late Proterozoic to Early Paleozoic normal faults related to the opening of the Iapetus Ocean. The absence of strata younger than the Ordovician makes difficult to determine when the faults reactivated after the Ordovician. Field relations between the normal faults bordering the SLRS and those produced by the Charlevoix impact crater suggest a reactivation of the rift younger than the Devonian, the estimated age of the impact. Apatite (U-Th)/He thermochronology is an adequate tool to recognize thermal events related to fault movements. A thermochronology study was then started along three transects across the SLRS, from Québec up to Charlevoix. Apatites were extracted and separated from five granitic to charnockitic gneisses and an amphibolite of Grenvillian age. The samples were exposed on hanging wall and footwall of the Montmorency and Saint-Laurent faults at three different locations along the SLRS. For precision and accuracy, each of the six samples was analyzed for radiogenic 4He and U-Th contents at least twice. Apatite grains were isolated by heavy liquids and magnetic separation. For each sample, ten apatite grains were selected under optical microscope and inserted into Pt capsules. Particular care was taken to isolate apatite free of mineral and fluid inclusions. Indeed, SEM investigations showed that some inclusions are U-rich monazite, which is a supplementary source of 4He to be avoided. The 4He content was determined by using a static noble gas mass spectrometer in CRPG-Nancy and duplicates using a quadrupole mass spectrometer at GEOTOP-UQAM. 4He was measured against internal He gas standards and Durango apatite, with the reference U-Th/He age of 31.13 ± 1.01 Ma. U and Th contents were determined at CRPG-Nancy and duplicated at McGill University by ICP-MS. Preliminary results of U-Th/He on St.-Laurent fault yield an age of 137±12 Ma for the hanging wall, at Sault-au-Cochon and 118±10 Ma for a sample from the footwall, at Cap-aux-oies. Previous Apatite Fission Track (AFT) performed for the two locations gave expected older ages at 149±16 Ma and 196±19 Ma for the hanging wall and the footwall, respectively. These preliminary U-Th/He results are consistent with AFT ages of the area (i.e. as expected, U-Th/He ages are younger than AFT ages) but do not yet provide new constraints for the structural evolution of the St. Lawrence rift system. We are determining further U-Th/He ages and these ages will constrain an exhumation model of the region.

  14. Sulfonylurea herbicides in an agricultural catchment basin and its adjacent wetland in the St. Lawrence River basin.

    PubMed

    de Lafontaine, Yves; Beauvais, Conrad; Cessna, Allan J; Gagnon, Pierre; Hudon, Christiane; Poissant, Laurier

    2014-05-01

    The use of sulfonylurea herbicides (SU) has increased greater than 100 times over the past 30 years in both Europe and North America. Applied at low rates, their presence, persistence and potential impacts on aquatic ecosystems remain poorly studied. During late-spring to early fall in 2009-2011, concentrations of 9 SU were assessed in two agricultural streams and their receiving wetland, an enlargement of the St. Lawrence River (Canada). Six SU in concentrations >LOQ (10 ng L(-1)) were detected in 10% or less of surface water samples. Rimsulfuron was detected each year, sulfosulfuron and nicosulfuron in two years and the others in one year only, suggesting that application of specific herbicides varied locally between years. Detection frequency and concentrations of SU were not significantly associated with total precipitation which occurred 1 to 5d before sampling. Concentrations and fate of SU differed among sites due to differences in stream dynamics and water quality characteristics. The persistence of SU in catchment basin streams reflected the dissipation effects associated with stream discharge. Maximum concentrations of some SU (223 and 148 ng L(-1)) were occasionally above the baseline level (100 ng L(-1)) for aquatic plant toxicity, implying potential toxic stress to flora in the streams. Substantially lower concentrations (max 55 ng L(-1)) of SU were noted at the downstream wetland site, likely as a result from dilution and mixing with St. Lawrence River water, and represent less toxicological risk to the wetland flora. Sporadic occurrence of SU at low concentrations in air and rain samples indicated that atmospheric deposition was not an important source of herbicides to the study area. PMID:24534695

  15. Trace metals in the Columbia River Estuary following the 18 May 1980 eruption of Mount St. Helens

    SciTech Connect

    Riedel, G.F.; Wilson, S.L.; Holton, R.L.

    1984-10-01

    Dissolved and suspended concentrations of cadmium, copper, iron, manganese, nickel, lead, and zinc were measured in the Columbia River Estuary following the 18 May 1980 eruption of Mount St. Helens. Soluble concentrations of these trace elements were not substantially elevated by the influx of volcanic ash and mud into the estuary during this period, except for somewhat higher than usual concentrations of manganese and copper. A laboratory experiment indicates that manganese leached from volcanic debris in fresh water and in the transition from fresh to slightly saline water probably caused the elevated Mn leaching from the material into fresh water.

  16. Establishment Patterns of Non-native Fishes: Lessons from the Duluth-Superior Harbor and Lower St. Louis River, an Invasion-prone Great Lakes Freshwater Estuary

    EPA Science Inventory

    The St. Louis River freshwater estuary which drains into western Lake Superior and includes the Duluth-Superior (MN-WI) harbor, has a long history of non-native fish introductions. From 1985 to 2002, seven new fishes were identified in the estuary, an unprecedented rate of non-n...

  17. Effects of zebra mussels, obtained from Lake Erie and St Lawrence River, as a food source on immune system of lesser scaup

    SciTech Connect

    Flipo, D.; Fournier, M.; Beaulieu, C.; Tessier, C.

    1995-12-31

    A feeding study was undertaken to assess the influence of a zebra mussel diet from Lake Erie and the St.Lawrence river on the immune system of lesser scaup. The Great lakes and the St.Lawrence river are known to be among the most contaminated waters found in the country. Analytical studies have shown that zebra mussels are contaminated by organochlorines and other pollutants. The occurrence of these toxicants in the food diet of lesser scaup can cause serious injuries. The immune system, in its capacity to destroy foreign particles and protect the host against diseases, can serve as a useful sentinel of the health status of these environmentally stressed organisms. Immune parameters of lesser scaup fed with zebra mussels from Lake Erie or the St. Lawrence river were evaluated. The duration of the feeding trial was nine weeks. Phagocytic activity and oxidative bursts of heterophils were evaluated by flow cytometry. Intracellular thiol levels of lymphocytes and heterophils were also determined by flow cytometry. The results showed a dimunition of phagocytic activity and bactericidal potential after 6 weeks of the zebra mussel diet compared to the control. These results may be associated with pathology problems encountered in treated groups at the end of the diet. Birds from the St. Lawrence River group (40%) and the Lake Erie group (40%) demonstrated variable degrees of pododermatitis compared to the control group. The intracellular level of thiol was consistently found to be elevated in lymphocytes and heterophyls from birds feeding with on the St. Lawrence River. In conclusion, flow cytometry assays like phagocytosis, oxidative burst and thiol staining can serve as biomarkers of the immune status of birds and can give important information for evaluating the health of birds exposed to environmental contamination.

  18. Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

    PubMed

    Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

    2012-10-15

    This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas. PMID:22858282

  19. The benthic macrofauna of the St. Lucia Estuary during the 2005 drought year

    NASA Astrophysics Data System (ADS)

    Pillay, D.; Perissinotto, R.

    2008-03-01

    The St. Lucia Estuary is the largest estuarine system in Africa. The estuary is part of the Greater St. Lucia Wetland Park, which has been declared a World Heritage Site. This ecosystem has been subjected to severe drought conditions over the last four to five years, resulting in its mouth being closed off from the ocean in June 2002 for a period of over four years. The main aim of this study was to document the effects of the prevailing drought on the macrofauna of the system, since the last work on this benthic component had been undertaken over a decade ago, during a normal-to-wet phase. Macrofauna samples together with physico-chemical data were collected at representative sites in the Narrows, and the South and North lakes in February, April, August and October 2005. The drought exerted a strong influence on the system, leading to hypersaline conditions developing in its northern regions (maximum of 126 at Hell's Gate), and to the loss of aquatic habitat. Ordinations and clustering indicated that the macrofauna of the system could generally be separated into three clusters viz. (1) the Narrows and the southern portion of South Lake, (2) the northern half of South Lake, and (3) the North Lake-False Bay complex. Multivariate correlations indicated weak relationships between macrofaunal community structure and physico-chemical parameters. The distinction in macrofaunal assemblages between these clusters was probably caused by these habitats being physically separated at the peak of the drought, with no water flow between them, thereby preventing exchange of planktonic larvae and retarding colonisation of habitats. There was a northward decline in taxonomic richness and diversity of macrofauna in the system, which correlated positively with water depth and negatively with the biomass of microphytobenthos. It is evident that the drought structured macrofauna communities primarily through its effects on water depth and habitat fragmentation. The results of this investigation provide valuable information regarding the effects of droughts on estuarine-lake systems and the possible mechanisms by which they occur.

  20. Optical water quality of a blackwater river estuary: the Lower St. Johns River, Florida, USA

    NASA Astrophysics Data System (ADS)

    Gallegos, Charles L.

    2005-04-01

    This paper reports measurements of absorption and scattering coefficients in relation to standard water quality measurements in the St. Johns River (Florida, USA), a blackwater river in which phytoplankton chlorophyll and non-algal particulates as well as colored dissolved organic matter (CDOM) contribute substantially to the inherent optical properties of the water. Extremely high concentrations of CDOM in this river present special problems for the measurement of inherent optical properties, such as the presence of very fine particulate matter that passes through most glass fiber filters. Empirical relationships are presented for estimating true dissolved absorption at very high CDOM concentrations. Specific-absorption and -scattering coefficients of suspended particulate matter varied widely, but appeared to decline steadily with salinity at salinities above 5, consistent with increasing influence of large-sized, unconsolidated mineral particulates with increasing tidal energy near the estuary mouth. Relationships are given for prediction of inherent optical properties from water quality concentrations for use in radiative transfer modeling, and changes in water quality measurements are recommended that can avoid the need for empirical corrections.

  1. Anthropogenic stable cesium in water and sediment of a shallow estuary, St. Louis Bay, Mississippi

    NASA Astrophysics Data System (ADS)

    Bera, Gopal; Yeager, Kevin M.; Shim, MooJoon; Shiller, Alan M.

    2015-05-01

    St. Louis Bay (SLB), Mississippi, is a small, shallow estuary with moderate local residential and industrial development. Dissolved, stable Cs (i.e., 133Cs) was significantly enriched in bay waters (up to 1570 nM) as compared to river (<1 nM) and ocean waters (2.3 nM). A TiO2 refinery, located on the north shore of the bay, is the likely source of the Cs, given that the highest Cs concentrations were found in waters and in surface sediments (up to 49 μg/g) near the refinery outfall. This setting presented a unique opportunity to study remobilization of Cs in a shallow estuarine system, where sediment resuspension is frequent. Remobilization (up to ∼3 fold increase) of dissolved Cs was observed during sediment resuspension events. A weak correlation between Cs and clay %; strong correlations among Cs, silt % and particulate organic carbon (POC); and simple numerical approaches indicate that desorption from resuspended particulate matter is the likely mechanism of Cs remobilization. Cs-enriched SLB waters can be traced to nearshore Mississippi Sound waters, but not into Mississippi Bight waters further offshore. The findings from this study also suggest that caution needs to be taken when interpreting the radio-cesium distribution in shallow estuarine and coastal systems.

  2. Diet and feeding periodicity of ruffe in the St. Louis River estuary, Lake Superior

    USGS Publications Warehouse

    Ogle, Derek H.; Selgeby, James H.; Newman, Raymond M.; Henry, Mary G.

    1995-01-01

    Ruffe Gymnocephalus cernuus, a percid native to Europe and Asia, is established in the Lake Superior drainage and could have negative impacts on native fish through competition for forage and predation on fish eggs. We investigated the diet of ruffes in the 4,654-ha St. Louis River estuary in May–October 1989–1990 and the feeding periodicity of ruffes in two adjacent habitats during five 24-h periods in summers 1990–1991. Ruffes were primarily benthophagous. Age-0 ruffes fed mostly on cladocerans and copepods in early summer and midge larvae (Chironomidae) in late summer and fall. Adult ruffes less than 12 cm fed mostly on midges and other macrobenthos but also consumed large numbers of microcrustaceans. Adult ruffes 12 cm and larger fed mostly on midges, burrowing mayflies Hexagenia spp., and caddisflies (Trichoptera). Ruffes consumed few fish eggs. Adult ruffes in deeper waters and all age-0 ruffes fed throughout the day as indicated by weight patterns of stomach contents. However, adult ruffes generally moved to shallower waters at night to feed most heavily. Results of this study indicate that ruffes will probably compete with other benthic-feeding fishes such as yellow perch Perca flavescens and trout-perch Percopsis omiscomaycus.

  3. Biochemical indicators of contaminant exposure in birds and turtles of the Great Lakes-St. Lawrence River

    SciTech Connect

    Bishop, C.; Trudeau, S.; Kennedy, S.; Norstrom, R.; Stegeman, J.

    1995-12-31

    Pre-fledgling chicks of tree swallows, double-crested cormorants, herring gulls, common terns and hatchling snapping turtles were collected from contaminated Areas of Concern and reference sites in the Great Lakes and St. Lawrence River to determine the geographic and species variation in biomarker responses. EROD activity in colonial waterbirds was generally an order of magnitude above EROD activity in tree swallows and snapping turtles. Notably, EROD activity in colonial waterbirds did not correlate with organochlorine contamination in livers at one industrialized site suggesting that exposure to other contaminants, possibly PAHs, may be an important factor. Retinol concentrations in cormorants were non-detectable and retinyl palmitate concentrations were equal or greater than those in herring gulls. In tree swallows, there was a significant negative correlation between vitamin A concentration in liver and kidney and EROD activity. In snapping turtles, there was a significant induction in EROD activity and significantly higher cytochrome P450 IAI level in livers from the Great Lakes site relative to a clean inland location. There were no significant differences in porphyrin concentrations between sites.

  4. Passive acoustic detection and localization of whales: effects of shipping noise in Saguenay-St. Lawrence Marine Park.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

    2008-06-01

    The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15 960 h of recordings in Saguenay-St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30 km for a receiver at the optimal depth. The 30 dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods. PMID:18537362

  5. Historical records of atmospheric metal deposition along the St. Lawrence Valley (eastern Canada) based on peat bog cores

    NASA Astrophysics Data System (ADS)

    Pratte, Steve; Mucci, Alfonso; Garneau, Michelle

    2013-11-01

    The recent history of atmospheric As, Cd, Ni, Pb and Zn deposition and the stable Pb isotope signatures were reconstructed from short cores collected at three peat bogs along the St. Lawrence Valley (SLV). The onset of industrial activity was recorded around 1810-1850 AD. As, Cd, Pb and, to a certain extent, Ni deposition rates reached maxima between 1940 and the early 1970s. Trace metals likely originated from coal-burning and ore smelting between 1850 and 1950 AD, and were replaced thereafter, at least in the case of Pb, by the combustion of leaded gasolines until the mid-1980s. Trace metal contents and accumulation rates were greater in the two cores recovered from the southwestern SLV than further northeast, as expected from their proximity to urban and industrial centers of eastern Canada and the U.S. Mid-West and the direction of the prevalent winds. A rapid decrease in metal accumulation rates since the 1970s suggests that mitigation policies were effective in reducing atmospheric metal emissions. Nevertheless, metal accumulation rates and stable Pb isotope signatures have not yet returned to their pre-industrial values.

  6. Estimation, analysis, sources, and verification of consumptive water use data in the Great Lakes-St. Lawrence River basin

    USGS Publications Warehouse

    Snavely, D.S.

    1988-01-01

    The Great Lakes-St. Lawrence River basin provides water for many uses and for wildlife habitat; thus many groups have developed strategies to manage the basin 's water resource. The International Joint Commission (IJC) is reviewing and comparing available consumptive-use data to assess the magnitude and effect of consumptive uses under present projected economic and hydraulic conditions on lake levels. As a part of this effort, the U.S. Geological Survey compared its own estimates of consumptive use in the United States with those generated by (1) the International Great Lakes Diversions and (2) the IJC. The U.S. Geological Survey also developed two methods of calculating consumptive-use projections for 1980 through 2000; one method yields an estimate of 6,490 cu ft/s for the year 2000; the other yields an estimate of 8,330 cu ft/s. These two projections could be considered the upper and lower limits for the year 2000. The reasons for the varying estimates are differences in (1) methods by which base year values were developed, and (2) the methods or models that were used to project consumptive-use values for the future. Acquisition of consumptive-use data from water users or governmental agencies or ministries would be desirable to minimize reliance on estimates. (USGS)

  7. Neoplastic and nonneoplastic hepatic changes in lake whitefish (Coregonus clupeaformis) from the St. Lawrence River, Quebec, Canada.

    PubMed

    Mikaelian, I; de Lafontaine, Y; Menard, C; Tellier, P; Harshbarger, J; Martineau, D

    1998-04-01

    As part of a survey of fish diseases, lake whitefish (Coregonus clupeaformis) were collected in fall 1995 from the St. Lawrence River 15 km upstream of Quebec City, Quebec, Canada, to assess the prevalence of liver lesions. A total of 141 fish were captured and necropsied, and three standard sections of liver were taken for histological examination. Prevalences of altered hepatocyte foci, hepatocellular carcinoma, cholangioma, and cholangiocarcinoma were 0.7%, 2.1%, 0.7%, and 2.1%, respectively. Thus, the overall prevalence of liver neoplasia was 4.9% (7/141). Hepatic tumors were only observed in fish 7 years old or older. Fish age was significantly and positively correlated with the index assessing the number and size of macrophage aggregates (p<0.001; rs = 0.16). Hepatocyte vacuolation, anisokaryosis, lymphocytic infiltration, and bile duct hyperplasia were also observed but were not related to the age, length, sex, or condition factor of the fish. These results represent the first report on a series of hepatic tumors in a wild salmonid species. PMID:9485481

  8. The Corossol structure: A possible impact crater on the seafloor of the northwestern Gulf of St. Lawrence, Eastern Canada

    NASA Astrophysics Data System (ADS)

    Lajeunesse, Patrick; St-Onge, Guillaume; Locat, Jacques; Duchesne, Mathieu J.; Higgins, Michael D.; Sanfaçon, Richard; Ortiz, Joseph

    2013-12-01

    We report on a 4.1 (±0.2) km diameter and 185 m deep circular submarine structure exposed on the seabed in >40 m water depths in the northwestern Gulf of St. Lawrence (Eastern Canada) from the analysis of high-resolution multibeam bathymetric and seismic data. The presence of a circular form characterized by a central uplift and concentric rings resembles the morphology and geometry of complex meteorite impact structures. Also, other origins, such as kimberlites, intrusions, karsts, or diapirs, can be eliminated on geological criteria. A single 4 cm long breccia fragment recovered from the central uplift has numerous glassy droplets of fluorapatite composition, assumed to be impact melts, and a single quartz grain with planar intersection features thought to be shock-induced planar deformation features (PDFs). The absolute age of this possible impact structure is unknown, but its geological setting indicates that it was formed long after the Mid-Ordovician and before regional pre-Quaternary sea-level lowstands. Present results outline the need for further examination to confirm an impact origin and to precisely date the formation of the structure.

  9. Shipping noise in whale habitat: characteristics, sources, budget, and impact on belugas in Saguenay-St. Lawrence Marine Park hub.

    PubMed

    Gervaise, Cédric; Simard, Yvan; Roy, Nathalie; Kinda, Bazile; Ménard, Nadia

    2012-07-01

    A continuous car ferry line crossing the Saguenay Fjord mouth and traffic from the local whale-watching fleet introduce high levels of shipping noise in the heart of the Saguenay-St. Lawrence Marine Park. To characterize this noise and examine its potential impact on belugas, a 4-hydrophone array was deployed in the area and continuously recorded for five weeks in May-June 2009. The source levels of the different vessel types showed little dependence on vessel size or speed increase. Their spectral range covered 33 dB. Lowest noise levels occurred at night, when ferry crossing pace was reduced, and daytime noise peaked during whale-watching tour departures and arrivals. Natural ambient noise prevailed 9.4% of the time. Ferry traffic added 30-35 dB to ambient levels above 1 kHz during crossings, which contributed 8 to 14 dB to hourly averages. The whale-watching fleet added up to 5.6 dB during peak hours. Assuming no behavioral or auditory compensation, half of the time, beluga potential communication range was reduced to less than ~30% of its expected value under natural noise conditions, and to less than ~15% for one quarter of the time, with little dependence on call frequency. The echolocation band for this population of belugas was also affected by the shipping noise. PMID:22779457

  10. Aquatic Vegetation of the St. Louis River Estuary: Initial Analysis of Point-intercept Data Collected in 2010 for Restoration Modeling.

    EPA Science Inventory

    A new effort to model aquatic vegetation patterns in the St. Louis River Estuary was initiated in summer of 2010 for the purpose of informing wetland restoration planning in the St. Louis River Area of Concern (AOC) at 40th Avenue West in Duluth. Aquatic vascular plants were doc...

  11. From yellow perch to round goby: A review of double-crested cormorant diet and fish consumption at three St. Lawrence River colonies, 1999–2013

    USGS Publications Warehouse

    Johnson, James H.; Farquhar, James F; Klindt, Rodger M; Mazzocchi, Irene; Mathers, Alastair

    2015-01-01

    The number of double-crested cormorants (Phalacrocorax auritus) in the upper St. Lawrence River has increased markedly since the early 1990s. In 1999, a binational study was initiated to examine the annual diet composition and fish consumption of cormorants at colonies in the upper river. Since 1999, 14,032 cormorant pellets, collected from May through September each year, have been examined from St. Lawrence River colonies to estimate fish consumption and determine temporal and spatial variation in diet. Seasonal variation in diet composition within a colony was low. Prior to 2006 yellow perch was the primary fish consumed by cormorants in the upper St. Lawrence River. Round goby were first observed in cormorant diets in 2003 and by 2006 were the main fish consumed at two of the three colonies. The time interval it took from the first appearance of round goby in the diet at a colony to when goby were the dominant prey species varied by island, ranging from two to five years. Daily fish consumption at each cormorant colony increased significantly from the pre-round goby to post-round goby period. The mean annual biomass of yellow perch consumed decreased significantly during the post-round goby period at the three colonies. Reduced consumption of yellow perch by cormorants may alleviate suspected localized impacts on perch near some of the larger river colonies.

  12. Rewriting the history of an extinction—was a population of Steller's sea cows (Hydrodamalis gigas) at St Lawrence Island also driven to extinction?

    PubMed Central

    Crerar, Lorelei D.; Crerar, Andrew P.; Domning, Daryl P.; Parsons, E. C. M.

    2014-01-01

    The Kommandorskiye Islands population of Steller's sea cow (Hydrodamalis gigas) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. The nitrogen-15 (δ15N)/carbon-13 (δ13C) values for bone samples from St Lawrence Island were significantly (p ≤ 0.05) different from Bering Island samples, indicating a second population. Bone samples were dated to between 1030 and 1150 BP (approx. 800–920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales (Balaena mysticetus), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history. PMID:25428930

  13. Rewriting the history of an extinction-was a population of Steller's sea cows (Hydrodamalis gigas) at St Lawrence Island also driven to extinction?

    PubMed

    Crerar, Lorelei D; Crerar, Andrew P; Domning, Daryl P; Parsons, E C M

    2014-11-01

    The Kommandorskiye Islands population of Steller's sea cow (Hydrodamalis gigas) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. The nitrogen-15 (δ(15)N)/carbon-13 (δ(13)C) values for bone samples from St Lawrence Island were significantly (p ≤ 0.05) different from Bering Island samples, indicating a second population. Bone samples were dated to between 1030 and 1150 BP (approx. 800-920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales (Balaena mysticetus), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history. PMID:25428930

  14. Holocene environmental and parasequence development of the St. Jones Estuary, Delaware (USA): Foraminiferal proxies of natural climatic and anthropogenic change

    USGS Publications Warehouse

    Leorri, E.; Martin, R.; McLaughlin, P.

    2006-01-01

    The benthic foraminiferal record of marshes located along western Delaware Bay (St. Jones Estuary, USA) reflects the response of estuaries to sea-level and paleoclimate change during the Holocene. System tracts are recognized and within them parasequences based on sedimentological and foraminiferal assemblages identification. The parasequences defined by foraminiferal assemblages appear correlative with rapid Holocene climate changes that are of worldwide significance: 6000-5000, 4200-3800, 3500-2500, 1200-1000, and 600??cal years BP. Following postglacial sea-level rise, modern subestuaries and marshes in the region began to develop between 6000 and 4000??years BP, depending on their proximity to the mouth of Delaware Bay and coastal geomorphology. Initial sediments were fluvial in origin, with freshwater marshes established around 4000??years BP. The subsequent sea-level transgression occurred sufficiently slowly that freshwater marshes alternated with salt marshes at the same sites to around 3000??years BP. Locally another two transgressions are identified at 1800 and 1000??years BP respectively. Marine influence increased in the estuaries until 600??years BP (Little Ice Age), when regression occurred. Sea-level began to rise again during the mid-19th Century at the end of the Little Ice Age, when marshes became established. The presence of a sand lens in the upper and middle estuary and the reduction in the number of tests in the top samples in cores from the same area also suggest an anthropogenic influence. The estuary infill resulted in a sharp transgressive sequence, represented by salt marsh foraminiferal assemblages in the upper part of the cores. The increase in marsh foraminifera in both areas suggests an increase in marine influence that might be due to the transgression beginning at the end of the Little Ice Age about 150-180??years ago coupled with anthropogenic straightening of the channel in 1913. ?? 2006 Elsevier B.V. All rights reserved.

  15. Evaluation of liver histopathology and EROD activity in St. Lawrence lake sturgeon (Acipenser fulvescens) in comparison with a reference population

    SciTech Connect

    Rousseaux, C.G. ||; Branchaud, A.; Spear, P.A.

    1995-05-01

    In an attempt to evaluate the effects of contaminants on the lake sturgeon Acipenser fulvescens, fish were netted from two sites: Riviere des Prairies, confluent with the St. Lawrence River near Montreal, and a reference site on the upper reaches of the Ottawa River in the La Verendrye Park. Livers of fish collected from the Riviere des Prairies were difficult to homogenize, and they left behind strands of what appeared to be connective tissue. Suspecting hepatic fibrosis, the authors decided to evaluate the livers for histopathologic changes. Nineteen adult lake sturgeon (eleven male and eight female) were examined. Following fixation, routine processing, sectioning, and staining with hematoxylin and eosin, microscopic evaluation revealed the following: Sections taken from livers of fish from the Riviere des Prairies site showed excessive fat accumulation and often severe chronic-active cholangiohepatitis. Bile duct proliferation (p < 0.0001), periportal fibrosis (p < 0.0001), inflammation (p < 0.001), and fat accumulation (p < 0.05) were more pronounced in the fish from the Riviere des Prairies site. Melano-macrophage centers appeared to be both paler and gave the appearance of fewer numbers (p < 0.01). Livers from lake sturgeon taken from the reference site had a more normal appearance. The EROD levels were also significantly induced in these fish (reference 3.39 {+-} 0.57; Riviere des Prairies site 8.21 {+-} 0.87 pmol/mg protein/min; p < 0.0005). The EROD levels positively correlated with bile duct proliferation (r{sup 2} = 0.44; p = 0.001) and periportal fibrosis (r{sup 2} = 0.41; p = 0.002). Despite the statistical associations above, the authors cannot categorically state that contaminants are the sole cause of the lesions seen.

  16. Trophic structure and mercury distribution in a Gulf of St. Lawrence (Canada) food web using stable isotope analysis.

    PubMed

    Lavoie, Raphael A; Hebert, Craig E; Rail, Jean-François; Braune, Birgit M; Yumvihoze, Emmanuel; Hill, Laura G; Lean, David R S

    2010-10-15

    Even at low concentrations in the environment, mercury has the potential to biomagnify in food chains and reaches levels of concern in apex predators. The aim of this study was to relate the transfer of total mercury (THg) and methylmercury (MeHg) in a Gulf of St. Lawrence food web to the trophic structure, from primary consumers to seabirds, using stable nitrogen (δ(15)N) and carbon (δ(13)C) isotope analysis and physical environmental parameters. The energy reaching upper trophic level species was principally derived from pelagic primary production, with particulate organic matter (POM) at the base of the food chain. We developed a biomagnification factor (BMF) taking into account the various prey items consumed by a given predator using stable isotope mixing models. This BMF provides a more realistic estimation than when using a single prey. Lipid content, body weight, trophic level and benthic connection explained 77.4 and 80.7% of the variation in THg and MeHg concentrations, respectively in this food web. When other values were held constant, relationships with lipid and benthic connection were negative whereas relationships with trophic level and body weight were positive. Total Hg and MeHg biomagnified in this food web with biomagnification power values (slope of the relationship with δ(15)N) of 0.170 and 0.235, respectively on wet weight and 0.134 and 0.201, respectively on dry weight. Values of biomagnification power were greater for pelagic and benthopelagic species compared to benthic species whereas the opposite trend was observed for levels at the base of the food chain. This suggests that Hg would be readily bioavailable to organisms at the base of the benthic food chain, but trophic transfer would be more efficient in each trophic level of pelagic and benthopelagic food chains. PMID:20810146

  17. Hazard assessment of a simulated oil spill on intertidal areas of the St. Lawrence River with SPMD-TOX

    USGS Publications Warehouse

    Johnson, B.T.; Petty, J.D.; Huckins, J.N.; Lee, Kenneth; Gauthier, J.

    2004-01-01

    Phytoremediation in a simulated crude oil spill was studied with a "minimalistic" approach. The SPMD-TOX paradigm - a miniature passive sorptive device to collect and concentrate chemicals and microscale tests to detect toxicity - was used to monitor over time the bioavailability and potential toxicity of an oil spill. A simulated crude oil spill was initiated on an intertidal freshwater grass-wetland along the St. Lawrence River southwest of Quebec City, Quebec, Canada. Several phytoremediation treatments were investigated; to dissipate and ameliorate the spill, treatments included nutrient amendments with inorganic nitrogen sources (ammonium nitrate and sodium nitrate) and phosphate (super triple phosphate) with and without cut plants, with natural attenuation (no phytoremedial treatment) as a control. Sequestered oil residues were bioavailable in all oil-treated plots in Weeks 1 and 2. Interestingly, the samples were colored and fluoresced under ultraviolet light. In addition, microscale tests showed that sequestered residues were acutely toxic and genotoxic, as well as that they induced hepatic P450 enzymes. Analysis of these data suggested that polycyclic aromatic hydrocarbons were among the bioavailable residues sequestered. In addition, these findings suggested that the toxic bioavailable fractions of the oil spill and degradation products dissipated rapidly over time because after the second week the water column contained no oil or detectable degradation products in this riverine intertidal wetland. SPMD-TOX revealed no evidence of bioavailable oil products in Weeks 4, 6, 8, and 12. All phytoremediation efforts appeared to be ineffective in changing either the dissipation rate or the ability to ameliorate the oil toxicity. SPMD-TOX analysis of the water columns from these riverine experimental plots profiled the occurrence, dissipation, and influence of phytoremediation on the bioavailability and toxicity of oil products (parent or degradation products. ?? 2004 Wiley Periodicals, Inc.

  18. Recent Carbon Accumulation Rates in Ombrotrophic Peatlands on the North Shore of the Gulf of the St. Lawrence, Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Sanderson, N. K.; Charman, D.; Garneau, M.; Hartley, I. P.

    2013-12-01

    In Eastern Canada, permafrost reached its southernmost extent for the Holocene during the Little Ice Age. Recent warming and degradation along the southern limit of the discontinuous permafrost zone is altering the microtopography, hydrology and carbon cycling in ombrotrophic peatlands; this trend is projected to continue. However, the understanding of multi-decadal and centennial scale change in peatlands is limited. This study aims to quantify changes in carbon accumulation rates for the last millennium in ombrotrophic peatlands from three regions along the North Shore of the Gulf of the St Lawrence, Canada. In each region, three peatlands were cored and 3-4 microforms were sampled per peatland. This replication allows changes in accumulation rates to be examined on two scales: 1) between regions along a N-S climatic gradient, and 2) within peatlands in the same region along a microtopography gradient. Recent carbon accumulation rates for last 150-200 years were calculated with lead-210 dates. Some initial estimates are also available for the last millennium using radiocarbon dates. Carbon accumulation rates were higher for all sites in the southernmost region, with sphagnum hummocks having the recent highest accumulation rates overall. In more northern peatlands, rates were found to differ between microforms, and between sites. This variability may be due to local differences in wind exposure and winter snow cover between sites. A high-resolution (0.5 cm) multi-proxy analysis using testate amoebae and plant macrofossils will be performed around key periods of accumulation change to evaluate peatland sensitivity and carbon accumulation to hydrological change.

  19. Novel flame retardants in urban-feeding ring-billed gulls from the St. Lawrence River, Canada.

    PubMed

    Gentes, Marie-Line; Letcher, Robert J; Caron-Beaudoin, Elyse; Verreault, Jonathan

    2012-09-01

    This study investigated the occurrence of a comprehensive suite of polybrominated diphenyl ethers (PBDEs) and current-use flame retardants (FRs) in ring-billed gulls breeding in a highly industrialized section of the St. Lawrence River, downstream from Montreal (QC, Canada). Despite major point-sources and diffuse contamination by FRs, nearly no FR data have been reported in birds from this area. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEHTBP) was detected in 89% of ring-billed gull livers (mean: 2.16 ng/g ww; max: 17.6 ng/g ww). To our knowledge, this is the highest detection frequency and highest concentrations reported thus far in any avian species or populations. Dechlorane Plus (DP) isomers were also particularly abundant (anti-DP detected in 100% and syn-DP in 93% of livers). Other detected FR compounds (3-14% detection) included 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) and β-1,2-dibromo-4-(1.2-dibromoethyl)-cyclohexane (β-TBECH). Mean BDE-209 (57.2 ± 12.2 ng/g ww) in ring-billed gull livers was unexpectedly high for this midtrophic gull species, exceeding levels reported in several apex raptors such as peregrine falcons. BDE-209's relative contribution to ∑PBDEs was on average 25% (exceeding BDE-47 and BDE-99) and contrasted with profiles typically reported for fish-eating gull species. The present study highlighted preoccupying gaps in upcoming FR regulations and stressed the need for further investigation of the sources of FR exposure in highly urbanized areas. PMID:22845168

  20. Contaminant residues in snapping turtle (Chelydra s. serpentina) eggs from the Great Lakes-St. Lawrence River basin (1999 to 2000).

    PubMed

    Ashpole, S L; Bishop, C A; Brooks, R J

    2004-08-01

    To determine temporal and geographic variations of environmentally persistent pollutants, the concentrations of several contaminants were measured in snapping turtle eggs in 1999 and 2000. Contaminants included polychlorinated biphenyls (PCBs), non- ortho PCBs, polychlorinated dibenzodioxins and furans, organochlorine pesticides, and total mercury. Egg collection sites within the St. Lawrence Area of Concern (AOC) and the Territory of Akwesasne included Turtle Creek, Snye Marsh, and Raquette River. Additional contaminated sites were Gray's Creek (within the St. Lawrence AOC boundary), Coote's Paradise (Hamilton Harbour AOC), and the Territory of Walpole Island (St. Clair AOC). Reference sites were Lake Sasajewun, Algonquin Provincial Park in central Ontario, and in close proximity to the St. Lawrence Area AOC, Hoasic Creek and Cooper Marsh. Eggs from clutches collected from Akwesasne contained the highest concentrations of contaminants. Mean total PCB concentrations for Akwesasne clutches ranged from 1,900 to 61,000 ng/g wet weight (w.w.), which was 360 to 3,100 times higher than the mean concentrations at the reference sites. The high levels of contaminants in eggs, from sites within Akwesasne, were consistent with trends reported in the past and reflect the influence of the proximity of heavy industry. Current contaminant concentrations in clutches from Coote's Paradise are comparable with those recorded in 1989 and 1990 but are 200 to 800 times lower than concentrations reported in 1984 and 1988. Eggs from Lake Sasajewun contained relatively low contaminant levels, which is consistent with atmospheric deposition. Our results support that snapping turtles are good indicators of temporal and geographic contaminant trends. PMID:15386150

  1. Distribution of submerged aquatic vegetation in the St. Louis River estuary: Maps and models (Presentation)

    EPA Science Inventory

    SAV provides the biophysical basis for several ecosystem services in Great Lakes estuaries including rearing and adult habitat for commercially and recreationally important fishes, foraging habit for waterfowl, and nutrient retention. Understanding sources of variation in SAV in ...

  2. Community-based participatory research projects and policy engagement to protect environmental health on St Lawrence Island, Alaska

    PubMed Central

    Miller, Pamela K.; Waghiyi, Viola; Welfinger-Smith, Gretchen; Byrne, Samuel Carter; Kava, Jane; Gologergen, Jesse; Eckstein, Lorraine; Scrudato, Ronald; Chiarenzelli, Jeff; Carpenter, David O.; Seguinot-Medina, Samarys

    2013-01-01

    Objectives This article synthesizes discussion of collaborative research results, interventions and policy engagement for St Lawrence Island (SLI), Alaska, during the years 2000–2012. Methods As part of on-going community-based participatory research (CBPR) studies on SLI, 5 discrete exposure-assessment projects were conducted: (a) a biomonitoring study of human blood serum; (b–d) 3 investigations of levels of contaminants in environmental media at an abandoned military site at Northeast Cape – using sediment cores and plants, semi-permeable membrane devices and blackfish, respectively; and (e) a study of traditional foods. Results Blood serum in residents of SLI showed elevated levels of polychlorinated biphenyls (PCBs) with higher levels among those exposed to the military site at Northeast Cape, an important traditional subsistence-use area. Environmental studies at the military site demonstrated that the site is a continuing source of PCBs to a major watershed, and that clean-up operations at the military site generated PCB-contaminated dust on plants in the region. Important traditional foods eaten by the people of SLI showed elevated concentrations of PCBs, which are primarily derived from the long-range transport of persistent pollutants that are transported by atmospheric and marine currents from more southerly latitudes to the north. Interventions An important task for all CBPR projects is to conduct intervention strategies as needed in response to research results. Because of the findings of the CBPR projects on SLI, the CBPR team and the people of the Island are actively engaging in interventions to ensure cleanup of the formerly used military sites; reform chemicals policy on a national level; and eliminate persistent pollutants internationally. The goal is to make the Island and other northern/Arctic communities safe for themselves and future generations. Conclusions As part of the CBPR projects conducted from 2000 to 2012, a series of exposure assessments demonstrate that the leaders of SLI have reason to be concerned about the health of people due to the presence of carcinogenic chemicals as measured in biomonitoring and environmental samples and important traditional foods. PMID:23977641

  3. Modeling the hydrology of wetlands and their response to climate change: Application to the St Lawrence Lowlands, Canada

    NASA Astrophysics Data System (ADS)

    Fossey, M.; Rousseau, A. N.; Savary, S.; Royer, A.

    2012-12-01

    The St Lawrence Lowlands, the most populated region of Quebec, Canada, are characterized by several ecosystems heavily affected by anthropogenic activities (e.g., agriculture, peat mining, and urbanization). Amongst these ecosystems, wetlands are facing major changes and deterioration that could have severe impacts on the overall hydrology of the area. For instance, over the last century nearly 45% of wetlands have disappeared in the watersheds of the Bécancour (2600 km2) and Yamaska (4850 km2) rivers with an increasing rate of the phenomenon over the past 40 years. Nowadays, wetlands represent 6% and 3% of the aforementioned watersheds, respectively. Since wetlands are thought to support low flows and flood mitigation services, these watersheds may be more vulnerable to climate change. The explicit accounting of wetlands in a distributed hydrological modeling framework may provide a means for an overall assessment of the role of wetlands at the watershed scale and of the estimation of their role in developing adaptation strategies (i.e., preservation/conservation). In this study, our main objectives are to integrate wetlands into an operational, distributed, hydrological model, and to quantify their impacts on the hydrological regime under current and changing climate conditions. To do so, we used HYDROTEL, a distributed hydrological model compatible with remote sensing and GIS data, to model the Bécancour and Yamaska watersheds. In the model, we categorized wetlands as either isolated or riparian according to their connection to the river network. Using hydrological observations from 1970 to 2010 and land cover maps from 2011, the model was first successfully calibrated over the 2000-2005 period and then validated over the 2005-2010 period. Meteorological outputs from the Canadian Regional Climate Model for the 1960-2100 period were then used as inputs to HYDROTEL. Preliminary results show that integration of wetlands in a distributed hydrological model can be successfully carried out in order to anticipate the impacts of climate change on the hydrological regime of the study watersheds. Globally, the results indicate that wetlands are an attractive option for the development of adaptation strategies to support low flows and flood mitigation services under changing climate conditions in southern Quebec, Canada.

  4. CHINESE MITTEN CRABS (ERIOCHEIR SINENSIS) IN THE ST. LAWRENCE RIVER (CANADA): NEW RECORDS AND RISK OF INVASION

    EPA Science Inventory

    The Chinese mitten crab, Eriocheir sinensis, is an internationally renowned aquatic invader. Native to China and North/South Korea, this catadromous crab has successfully invaded several rivers and estuaries in eleven countries in Western Europe as well as the San Francisco Bay ...

  5. Spatial dynamics of biogeochemical processes in the St. Louis River freshwater estuary

    EPA Science Inventory

    In the Great Lakes, river-lake transition zones within freshwater estuaries are hydrologically and biogeochemically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. The goal of our study was to characterize the biogeochemical properties of th...

  6. Chlorinated hydrocarbons and mercury in sediments, red-winged blackbirds (Agelaius phoeniceus) and tree swallows (Tachycineta bicolor) from wetlands in the Great Lakes-St. Lawrence River basin

    SciTech Connect

    Bishop, C.A.; Koster, M.D.; Chek, A.A.; Hussell, D.J.T.; Jock, K.

    1995-03-01

    In 1991, the authors collected red-winged blackbird (Agelauis phoeniceus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings, and sediment samples from 2 wetland sites in the Great lakes and St. Lawrence River basin. They analyzed for chlorinated hydrocarbons and total mercury and found that biota contained contaminant concentrations which were one to two orders of magnitude above those in sediments. Maximum concentrations of contaminants were found in Akwesasne, St. Lawrence river (PCBs = 18,558.8 ng/g in red-winged blackbird eggs, oxychlordane = 58.8/g and mirex = 40.1 ng/g in tree swallow eggs); Mud Creek, Lake Erie and Cootes Paradise. Despite the migratory habits of red-winged blackbirds and tree swallows, agreement among biota and sediment in geographic variation of contaminant concentrations supports the use of these animals as biomonitors of persistent chemicals. Although chlorinated hydrocarbon concentrations in red-winged blackbird eggs were significantly correlated with sediment contamination, the local nature of the tree swallow chick diet suggests that nestlings would be the best indicator of local contaminant trends.

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

    USGS Publications Warehouse

    Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

    2006-01-01

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

  8. Detection and confirmation of saxitoxin analogues in freshwater benthic Lyngbya wollei algae collected in the St. Lawrence River (Canada) by liquid chromatography-tandem mass spectrometry.

    PubMed

    Lajeunesse, André; Segura, Pedro A; Gélinas, Malorie; Hudon, Christiane; Thomas, Krista; Quilliam, Michael A; Gagnon, Christian

    2012-01-01

    The presence of cyanotoxins in benthic Lyngbya wollei algae samples collected in a fluvial lake along the St. Lawrence River, Canada, was investigated using a multi-toxins method. Hydrophilic interaction liquid chromatography (HILIC) and reverse phased liquid chromatography (RPLC) were coupled to triple quadrupole mass spectrometry (LC-QqQMS) for quantification and to quadrupole-time of flight mass spectrometry (LC-QqTOFMS) for screening and confirmation. The presence of two saxitoxin analogues, LWTX-1 and LWTX-6, was confirmed in benthic Lyngbya wollei algae samples. Concentration of LWTX-1 was between 209±5 and 279±9 μg g(-1). No other targeted cyanotoxin (such as anatoxin-a, nodularin, microcystin-LR, microcystins-RR and saxitoxin) was found in the samples. The presence of LWTX-6 was observed by using a screening approach based on an in-house database of cyanotoxins, an algorithm of identification and high resolution mass spectrometry measurements on the precursor and product ions. This work demonstrates the need for more research on the fate of benthic cyanotoxins in aquatic ecosystems such the St. Lawrence River. PMID:22169195

  9. Toxicity of waters from the St. Lawrence River at Massena Area-of-Concern to the plankton species Selenastrum capricornutum and Ceriodaphnia dubia

    USGS Publications Warehouse

    Baldigo, Barry P.; Duffy, Brian T.; Nally, Christopher J.; David, Anthony M.

    2012-01-01

    In 1972, the US and Canada committed to restore the chemical, physical, and biological integrity of the Great Lakes Ecosystem under the first Great Lakes Water Quality Agreement. During subsequent amendments, part of the St. Lawrence River at Massena NY, and segments of three tributaries, were designated as one Area of Concern (AOC) due to various beneficial use impairments (BUIs). Plankton beneficial use was designated impaired within this AOC because phytoplankton and zooplankton population data were unavailable or needed “further assessment”. Contaminated sediments from industrial waste disposal have been largely remediated, thus, the plankton BUI may currently be obsolete. The St. Lawrence River at Massena AOC remedial action plan established two criteria which may be used to assess the plankton BUI; the second states that, “in the absence of community structure data, plankton bioassays confirm no toxicity impact in ambient waters”. This study was implemented during 2011 to determine whether this criterion was achieved. Acute toxicity and chronic toxicity of local waters were quantified seasonally using standardized bioassays with green alga Selenastrum capricornutum and water flea Ceriodaphnia dubia to test the hypothesis that waters from sites within the AOC were no more toxic than were waters from adjacent reference sites. The results of univariate and multivariate analyses confirm that ambient waters from most AOC sites (and seasons) were not toxic to both species. Assuming both test species represent natural plankton assemblages, the quality of surface waters throughout most of this AOC should not seriously impair the health of resident plankton communities.

  10. Crocodiles count on it: Regulation of discharge to Lake St Lucia Estuary by a South African peatland

    NASA Astrophysics Data System (ADS)

    Price, J. S.; Grundling, P.; Grootjans, A.

    2010-12-01

    The Mfabeni mire is located within the iSimangaliso Wetland Park in north-eastern KwaZulu-Natal Province on the Indian Ocean sea-board of South Africa. This mire complex includes open peatland with occurrences of sedge communities, Sphagnum (rare in South Africa), and swamp forest which is common in the region (but rare in South Africa). It is one of the largest (1650 ha), thickest (10.8 m of peat) and the oldest (~45,000 years Before Present) known peatlands in South Africa. The mire is almost pristine, with very few disturbances. In the past the surrounding area supported pine plantations but these alien trees were recently removed, with conservation and tourism the primary designated activities. Surface and groundwater exchanges to and within the mire and its surrounding coastal dune landscape were studied. Profiles of electrical conductivity and major cations and anions, as well as natural isotopes (δ2H and δ18O) in water samples of ground and surface water were also analysed to develop a conceptual model of the system’s hydrological function. Water efflux from an inland dune complex provides substantial recharge towards Mfabeni, while coastward hydraulic gradients from the dune complex through the wetland are evident. Consequently, the linkages between the dune system and Mfabeni, and the peatland’s water regulation function, dictate the nature and magnitude of the local freshwater discharge to the estuary, and internal water exchanges that control peatland ecological function. The hydrograph from the stream outlet indicate an initial rapid response in increased flows after major rainfall events but with a delayed drawdown over time reflecting the contribution of the relatively large size of the mire (comprising 38% of the catchment) in attenuating flood events and ensuring sustained flow to the estuary. Freshwater discharge from the Mfabeni mire to the St. Lucia estuary, which has provided refuge for aquatic species during periods of drought, may become crucial under a more erratic climate.

  11. Chemical and microbial contamination baseline in the Saguenay-St. Lawrence Marine Park (Eastern Canada): concentrations and fluxes from land-based sources.

    PubMed

    Lemaire, Nicolas; Pelletier, Émilien

    2013-10-01

    Stretching halfway between the Canadian Great Lakes and the Atlantic Ocean, the Saguenay-St. Lawrence Marine Park is subject to environmental issues being exposed to untreated or uncontrolled point and non-point sources of anthropogenic contamination. This article provides a first estimation of chemical and microbial contamination entering the marine park from the discharges of local municipal effluents and the inputs of tributaries in the summer period. Suspended particulate matter (SPM), nutrients, particulate carbon (PC) and nitrogen, trace metals, and fecal coliform bacteria were determined in surface brackish waters at upstream boundaries, in freshwater of 11 tributaries, and in nine sewage effluents from small communities settled along the marine park. Most tributaries have SPM < 10 mg L(-1) and contributed to a total of ~47 tons day(-1), thus representing a small proportion of daily SPM transported by Saguenay River (200 tons day(-1)) and St. Lawrence River (6.3 × 10(3) tons day(-1)). As expected, untreated sewage effluents showed high fecal contamination (0.2-6.0 × 10(6) CFU 100 mL(-1)), high NO x levels (4-33 μmol L(-1)) and high concentrations of particulate organic carbon (7-62 mg L(-1)). However, all tributaries had low coliforms (<230 CFU 100 mL(-1)), low PC (0.3-1.1 mg L(-1)), and low nutrients (NO(x) < 3.3 μmol L(-1)), with the exception of the Moulin-à-Baude River, a small tributary (2.3 × 10(5) m(3) day(-1)) clearly contaminated by human activities. Detailed analysis of 14 metals and metalloids in SPM did not show any clear contamination trend between sewage effluents and tributaries, except for Grandes-Bergeronnes River, where most trace metals appeared to be greater than for other rivers. Regarding global inputs, results showed that despite their relatively high pollutants load, inputs from local sewages and small tributaries remained minor contributors compared with upstream inputs, i.e., Saguenay River and St. Lawrence River. However, we illustrate that some local hydrodynamic factors in bays and inlets must be taken into account when evaluating risks associated with sewage discharges. PMID:23695715

  12. Glacially-megalineated limestone terrain of Anticosti Island, Gulf of St. Lawrence, Canada; onset zone of the Laurentian Channel Ice Stream

    NASA Astrophysics Data System (ADS)

    Eyles, Nick; Putkinen, Niko

    2014-03-01

    Anticosti is a large elongate island (240 km long, 60 km wide) in eastern Canada within the northern part of a deep water trough (Gulf of St. Lawrence) that terminates at the Atlantic continental shelf edge. The island's Pleistocene glaciological significance is that its long axis lay transverse to ice from the Quebec and Labrador sectors of the Laurentide Ice Sheet moving south from the relatively high-standing Canadian Shield. Recent glaciological reconstructions place a fast-flowing ice stream along the axis of the Gulf of St. Lawrence but supporting geologic evidence in terms of recognizing its hard-bedded onset zone and downstream streamlined soft bed is limited. Anticosti Island consists of gently southward-dipping limestone plains composed of Ordovician and Silurian limestones (Vaureal, Becscie and Jupiter formations) with north-facing escarpments transverse to regional ice flow. Glacial deposits are largely absent and limestone plains in the higher central plateau of the island retain a relict apparently ‘preglacial’ drainage system consisting of deeply-incised dendritic bedrock valleys. In contrast, the bedrock geomorphology of the lower lying western and eastern limestone plains of the island is strikingly different having been extensively modified by glacial erosion. Escarpments are glacially megalineated with a distinct ‘zig-zag’ planform reflecting northward-projecting bullet-shaped ‘noses’ (identified as rock drumlins) up to 2 km wide at their base and 4 km in length with rare megagrooved upper surfaces. Drumlins are separated by southward-closing, funnel-shaped ‘through valleys’ where former dendritic valleys have been extensively altered by the streaming of basal ice through gaps in the escarpments. Glacially-megalineated bedrock terrain such as on the western and eastern flanks of Anticosti Island is elsewhere associated with the hard-bedded onset zones of fast flowing ice streams and provides important ground truth for the postulated Laurentian Channel Ice Stream (LCIS) within the Gulf of St. Lawrence sector of the Laurentide Ice Sheet.

  13. Continuous analysis of dissolved gaseous mercury and mercury volatilization in the upper St. Lawrence River: exploring temporal relationships and UV attenuation.

    PubMed

    O'Driscoll, N J; Poissant, L; Canário, L; Ridal, J; Lean, D R S

    2007-08-01

    The formation and volatilization of dissolved gaseous mercury (DGM) is an important mechanism by which freshwaters may naturally reduce their mercury burden. Continuous analysis of surface water for diurnal trends in DGM concentration (ranging from 0 to 60.4 pg L(-1); n=613), mercury volatilization (ranging from 0.2 to 1.1 ng m(-2) h(-1); n=584), and a suite of physical and chemical measurements were performed during a 68 h period in the St. Lawrence River near Cornwall (Ontario, Canada) to examine the temporal relationships governing mercury volatilization. No lag-time was observed between net radiation and OGM concentrations (highest cross-correlation of 0.817), thus supporting previous research indicating faster photoreduction kinetics in rivers as compared to lakes. A significant lag-time (55-145 min; maximum correlation = 0.625) was observed between DGM formation and mercury volatilization, which is similar to surface water Eddy diffusion times of 42-132 min previously measured in the St. Lawrence River. A depth-integrated DGM model was developed using the diffuse integrated vertical attenuation coefficients for UVA and UVB (K(dI UVA) = 1.45 m(-1) K(dI UVB)= 3.20 m(-1)) Low attenuation of solar radiation was attributed to low concentrations of dissolved organic carbon (mean = 2.58 mg L(-1) and particulate organic carbon (mean = 0.58 mg L(-1) in the St. Lawrence River. The depth-integrated DGM model developed found that the top 0.3 m of the water column accounted for only 26% of the total depth-integrated DGM. A comparison with volatilization data indicated that a large portion (76% or 10.5 ng m(-2) of the maximum depth-integrated DGM (13.8 ng m(-2))is volatilized over a 24 h period. Therefore, at least 50% of all DGM volatilized was produced at depths below 0.3 m. These results highlight the importance of solar attenuation in regulating DGM formation with depth. The results also demonstrate both the fast formation of DGM in rivers and the importance of understanding DGM dynamics with depth as opposed to surface waters. PMID:17822100

  14. Southeast Atlantic coast estuaries, Sapelo Sound to St. Simons Sound. Georgia: circulation survey, 1980

    SciTech Connect

    Watson, W.A.

    1984-01-01

    The purpose of the report is to inform potential users of the data collected during the National Ocean Service (NOS) 1980 circulation survey in the Georgia estuaries. The report presents information on station locations, periods of occupation, instruments, sampling rate, data quality, and processing procedures. The measurement of atmospheric parameters is necessary for the study of nontidal water movement caused by winds and changing atmospheric pressure. Another benefit derived from current data collected is as an aid in the prediction of oil-spill and pollutant transport.

  15. Endocrine and metabolic dysfunction in yellow perch, Perca flavescens, exposed to organic contaminants and heavy metals in the St. Lawrence River

    SciTech Connect

    Hontela, A.; Duclos, D.; Fortin, R.; Dumont, P.

    1995-04-01

    The endocrine and biochemical responses to the acute stress of capture and handling were investigated in sexually mature and in immature male and female yellow perch, Perca flavescens, from a site contaminated by organic contaminants (PAHs and PCBs) and heavy metals (Hg, Cd, As, and Zn) and from a reference site in the St. Lawrence River. Following a standardized capture and handling stress, fish from the contaminated site did not exhibit the expected physiological stress response observed in fish from the reference site. Blood cortisol and thyroxine levels were lower, and liver glycogen stores were greater in mature males and females, as well as in the immature fish from the contaminated site, compared to the reference site. Fish from the contaminated site also had smaller gonads and lower condition factor. The impaired ability to elevate blood cortisol in response to an acute stress may be used as a biomarker of toxic stress in health assessment of feral fish from polluted environments.

  16. Persistent organochlorine pesticide exposure related to a formerly used defense site on St. Lawrence Island, Alaska: data from sentinel fish and human sera

    PubMed Central

    Byrne, Samuel; Miller, Pamela; Waghiyi, Viola; Buck, C. Loren; von Hippel, Frank A.; Carpenter, David O.

    2015-01-01

    St. Lawrence Island, Alaska is the largest island in the Bering Sea, located 60 km from Siberia. The island is home to approximately 1600 St. Lawrence Island Yupik residents who live a subsistence lifestyle. Two formerly used defense sites (FUDS) exist on the island, one of which, Northeast Cape, has been the subject of a $123 million cleanup effort. Environmental monitoring demonstrates localized soil and watershed contamination with polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and arsenic. This study examined whether the Northeast Cape FUDS is a source of exposure to OC pesticides. A total of 71 serum samples were collected during site remediation from volunteers that represented three geographic regions of the island. Additionally, ninespine stickleback (Pungitius pungitius) and Alaska blackfish (Dallia pectoralis) were collected from Northeast Cape after remediation to assess continuing presence of OC pesticides. Chlordane compounds, DDT compounds, mirex and hexachlorobenzene (HCB) were the most prevalent and present at the highest concentrations in both fish tissues and human serum samples. After controlling for age and sex, activities near the Northeast Cape FUDS were associated with an increase in serum HCB as compared to residents of the farthest village from the site. Positive but non-significant relationships for sum-chlordane and sum-DDT were also found. Organochlorine concentrations in fish samples did not show clear geographic trends, but appear elevated compared to other sites in Alaska. Taken together, the results suggest that contamination of the local environment at the Northeast Cape FUDS may increase exposure to select persistent OC pesticides. PMID:26262441

  17. Fossil brines preserved in the St-Lawrence Lowlands, Québec, Canada as revealed by their chemistry and noble gas isotopes

    NASA Astrophysics Data System (ADS)

    Pinti, Daniele L.; Béland-Otis, Catherine; Tremblay, Alain; Castro, Maria Clara; Hall, Chris M.; Marcil, Jean-Sébastien; Lavoie, Jean-Yves; Lapointe, Raynald

    2011-08-01

    Brines in Cambrian sandstones and Ordovician dolostones of the St-Lawrence Lowlands at Bécancour, Québec, Canada were sampled for analysis of all stable noble gases in order to trace their origin and migration path, in addition to quantifying their residence time. Major ion chemistry indicates that the brines are of Na-Ca-Cl type, possibly derived from halite dissolution. 87Sr/ 86Sr ratios and Ca excess indicate prolonged interactions with silicate rocks of the Proterozoic Grenville basement or the Cambrian Potsdam sandstone. The brines constrain a 2-3% contribution of mantle 3He and large amounts of nucleogenic 21Ne ∗ and 38Ar ∗ and radiogenic 4He and 40Ar ∗. 4He/ 40Ar ∗ and 21Ne ∗/ 40Ar ∗ ratios, corrected for mass fractionation during incomplete brine degassing, are identical to their production ratios in rocks. The source of salinity (halite dissolution), plus the occurrence of large amounts of 40Ar ∗ in brines constrain the residence time of Bécancour brines as being older than the Cretaceous. Evaporites in the St-Lawrence Lowlands likely existed only during Devonian-Silurian time. Brines might result from infiltration of Devonian water leaching halite, penetrating into or below the deeper Cambrian-Ordovician aquifers. During the Devonian, the basin reached temperatures higher than 250 °C, allowing for thermal maturation of local gas-prone source rocks (Utica shales) and possibly facilitating the release of radiogenic 40Ar ∗ into the brines. The last thermal event that could have facilitated the liberation of 40Ar ∗ into fluids and contributed to mantle 3He is the Cretaceous Monteregian Hills magmatic episode. For residence times younger than the Cretaceous, it is difficult to find an appropriate source of salinity and of nucleogenic/radiogenic gases to the Bécancour brines.

  18. Changes in the northern Gulf of St. Lawrence ecosystem estimated by inverse modelling: Evidence of a fishery-induced regime shift?

    NASA Astrophysics Data System (ADS)

    Savenkoff, Claude; Castonguay, Martin; Chabot, Denis; Hammill, Mike O.; Bourdages, Hugo; Morissette, Lyne

    2007-07-01

    Mass-balance models have been constructed using inverse methodology for the northern Gulf of St. Lawrence for the mid-1980s, the mid-1990s, and the early 2000s to describe ecosystem structure, trophic group interactions, and the effects of fishing and predation on the ecosystem for each time period. Our analyses indicate that the ecosystem structure shifted dramatically from one previously dominated by demersal (cod, redfish) and small-bodied forage (e.g., capelin, mackerel, herring, shrimp) species to one now dominated by small-bodied forage species. Overfishing removed a functional group in the late 1980s, large piscivorous fish (primarily cod and redfish), which has not recovered 14 years after the cessation of heavy fishing. This has left only marine mammals as top predators during the mid-1990s, and marine mammals and small Greenland halibut during the early 2000s. Predation by marine mammals on fish increased from the mid-1980s to the early 2000s while predation by large fish on fish decreased. Capelin and shrimp, the main prey in each period, showed an increase in biomass over the three periods. A switch in the main predators of capelin from cod to marine mammals occurred, while Greenland halibut progressively replaced cod as shrimp predators. Overfishing influenced community structure directly through preferential removal of larger-bodied fishes and indirectly through predation release because larger-bodied fishes exerted top-down control upon other community species or competed with other species for the same prey. Our modelling estimates showed that a change in predation structure or flows at the top of the trophic system led to changes in predation at all lower trophic levels in the northern Gulf of St. Lawrence. These changes represent a case of fishery-induced regime shift.

  19. Comparison of the 1st, 2nd and 3rd generation Lawrence Livermore National Laboratory Torso phantoms.

    PubMed

    Kramer, G H; Hauck, B M

    2002-01-01

    The Lawrence Livermore National Laboratory (LLNL) Torso phantom, which is the de facto standard for lung counter calibration for low energy photon emitters, has undergone a number of revisions since its development. The first generation used real human bone: the second generation used synthetic bone and had a major design change; the third generation had more subtle material and mould changes. This work has compared a first generation, two second generation, and two third generation LLNL phantoms to see if there are any differences between the phantoms. The comparison of five LLNL phantoms using the same counting regions has shown that the second and third generation phantoms are essentially equivalent at low photon energies, but the first generation phantom shows an increased counting efficiency at low photon energies due to a design flaw. It is also apparent that these phantoms have maintained their performance characteristics over an extended period of time. PMID:12474942

  20. Vertical distribution and water solubility of phosphorus and heavy metals in sediments of the St. Lucie Estuary, South Florida, USA

    NASA Astrophysics Data System (ADS)

    He, Z. L.; Zhang, M.; Stoffella, P. J.; Yang, X. E.

    2006-05-01

    Accumulation and distribution of heavy metals and phosphorus in sediments impact water quality. There has been an increasing concern regarding fish health in the St. Lucie Estuary, which is related to increased inputs of nutrients and metals in recent decades. To investigate vertical changes of contaminants (P, Cd, Cr, Co, Cu, Ni, Pb, Zn, and Mn) in sediments of the St. Lucie Estuary in South Florida, 117 layer samples from six of the 210 to 420 cm depth cores were analyzed for their total and water-soluble P and heavy metals, clay, total Fe, Al, K, Ca, Mg, Na, and pH. Principal component analysis (PCA) was used in two sets of analytical data (total and water-soluble contaminant concentrations) to document changes of contaminants in each core of sediments. The PCA of total contaminants and minerals resulted in two factors (principal components). The first and second factors accounted for 61.7 and 17.2 % of the total variation in all variables, and contrast indicators associated with contaminants of P, Cd, Co, Cr, Ni, Pb, Zn, and Mn and accumulation of Fe and Al oxides, respectively. The first factor could be used for overall assessment of P and heavy metal contamination, and was higher in the upper 45-90 cm than the lower depths of each core. The concentrations of P and heavy metals in the surface layers of sediments significantly increased, as compared with those in the sediments deeper than 45-90 cm. The PCA of water-soluble contaminants developed two factors. The second factor (Cu-P) was higher in the upper than the lower depths of the sediment, whereas the highest score of the first factor (Cd-Co-Cr-Ni-Pb-Zn-Mn) occurred below 100 cm. The water-soluble Cu and P concentrations were mainly dependent on their total concentrations in the sediments, whereas the water-soluble Cd, Co, Cr, Ni, Pb, Zn, and Mn concentrations were mainly controlled by pH.

  1. Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada).

    PubMed

    Hamelin, Stéphanie; Planas, Dolors; Amyot, Marc

    2015-04-15

    Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (Km) and demethylation (Kd) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of (199)HgO and Me(200)Hg stable isotopes as tracers. A direct relationship was observed between Km (0.002 to 0.137 d(-1)) and [MeHg] in periphyton. A similar relationship was found between Kd (0.096 to 0.334 d(-1)) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat. PMID:25644842

  2. Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

    USGS Publications Warehouse

    Patino, Eduardo; Byrne, Michael J.

    2004-01-01

    Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the empirical equations seems to be limited by the number and distribution of suspended-solids samples collected throughout the expected concentration range at the North Fork and Speedy Point sites. Additionally, the ABS relations for both sites seem to overestimate at the low end and underestimate at the high end of the concentration range. Based on the sensitivity analysis, temperature had a greater effect than salinity on estimated suspended-solids concentrations. Temperature also appeared to affect ABS data, perhaps by changing the absorptive and reflective characteristics of the suspended material. Salinity and temperature had no observed effects on the turbidity relation at the North Fork and Speedy Point sites. Estimates of suspended-solids concentrations using ABS data were less 'erratic' than estimates using turbidity data. Combining ABS and turbidity data into one equation did not improve the accuracy of results, and therefore, was not considered.

  3. Putting oxygen and temperature thresholds of marine animals in context of environmental change in coastal seas: a regional perspective for the Scotian Shelf and Gulf of St. Lawrence

    NASA Astrophysics Data System (ADS)

    Brennan, Catherine E.; Blanchard, Hannah; Fennel, Katja

    2014-05-01

    We surveyed the literature in order to compile reported oxygen, temperature, salinity and depth preferences and thresholds of important marine species found in the Gulf of St. Lawrence and the Scotian Shelf regions of the northwest North Atlantic. We determined species importance based on the existence of a commercial fishery, a threatened or at risk status, or by meeting the following criteria: bycatch, baitfish, invasive, vagrant, important for ecosystem energy transfer, and predators and prey of the above species. Using the dataset compiled for the 53 regional fishes and macroinvertebrates, we rank species (including for different lifestages) by their maximum thermal limit, as well as by the lowest oxygen concentration tolerated before negative impacts (e.g. physiological stress), 50% mortality or 100% mortality are experienced. Additionally, we compare these thresholds to observed marine deoxygenation trends at multiple sites, and observed surface warming trends. This results in an assessment of which regional species are most vulnerable to future warming and oxygen depletion, and a first-order estimate of the consequences of thermal and oxygen stress on a highly productive marine shelf. If regional multi-decadal oxygen and temperature trends continue through the 21st century, many species will lose favorable oxygen conditions, experience oxygen-stress, or disappear due to insufficient oxygen. Future warming can additionally displace vulnerable species, though we note that large natural variability in environmental conditions may amplify or dampen the effects of anthropogenic surface warming trends. This dataset may be combined with regional ocean model predictions to map future species distributions.

  4. Intra- and inter-species differences in persistent organic contaminants in the blubber of blue whales and humpback whales from the Gulf of St. Lawrence, Canada.

    PubMed

    Metcalfe, Chris; Koenig, Brenda; Metcalfe, Tracy; Paterson, Gordon; Sears, Richard

    2004-05-01

    Biopsy samples of blubber from adult male and female blue whales, and from female and young-of-the-year humpback whales were collected during the summers of 1992-1999 in the Gulf of St. Lawrence, Canada. In blue whales, concentrations of 25 PCB congeners, DDT and metabolites and several other organochlorine compounds were present at higher concentrations in the blubber of males relative to females; reflecting maternal transfer of these persistent contaminants from females into young. Sex-related differences in concentrations were not observed with less persistent contaminants, such as HCHs. In humpback whale samples, there were no significant differences in the concentrations of PCBs and organochlorine compounds in the blubber of females and calves. These data indicate that calves quickly bioaccumulate contaminants by transplacental and lactational routes to concentrations that are in equilibrium with females. In comparisons between contaminant concentrations and patterns in the blubber of female blue and humpback whales, there were no significant differences in concentrations, but the proportions of some PCB congeners, HCH isomers, and DDT and its metabolites were different in the two baleen whale species. These may reflect differences in the diet of the two species, since fish comprise a large part of the diet of humpback whales and blue whales feed exclusively on euphausiid crustaceans (i.e. krill). PMID:14749058

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

    USGS Publications Warehouse

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

    2007-01-01

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

  6. Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model

    NASA Astrophysics Data System (ADS)

    Pellerin, Pierre; Roy, François; Dick, Sarah; Smith, Greg; Dupont, Fred; Pilon, Mark; Senneville, Simon; Chanut, Jerome

    2015-04-01

    The Canadian operational Gulf of St. Lawrence (GSL) coupled environmental forecast system has been updated with a new ocean-ice component (NEMO-CICE) and coupling methodology. The use of NEMO-CICE will facilitate future advances toward an increase in resolution and the introduction of new scientific developments. Indeed NEMO and CICE are supported by a large scientific community and are based on more efficient computing technologies than the current system. An ensemble of hindcasts over previous years demonstrate that recent developments in the NEMO-CICE model make it possible to meet the high quality standards of the ocean model by Saucier et al. (2009) used in the previous operational system in terms of the tides, circulation and water mass properties. We present results from these hindcasts as well as from an experimental run for the winter of 2014 and compare them with the operational system. The experimental run includes a pseudo-analysis cycle producing daily initial ice-ocean conditions and their subsequent coupled atmosphere-ice-ocean 48 hr forecasts. We first examine extreme weather event cases, and then present results from a subjective evaluation as well as objective skill scores for SST analyses and for ice, surface air temperature and wind forecasts. The importance of the two-way coupling will also be assessed.

  7. Influence of species and sex on metal residues in freshwater mussels (Family Unionidae) from the St. Lawrence River, with implications for biomonitoring programs

    SciTech Connect

    Metcalfe-Smith, J.L. . Rivers Research Branch)

    1994-09-01

    The implementation of freshwater mussel watch programs has been hindered by a lack of information on biological factors affecting the levels of contaminants accumulated by these organisms. This study investigated the influence of species and sex on metal residues in Elliptio complanata and Lampsilis radiata radiata (Family Unionidae) from the St. Lawrence River. Mussels were collected from sites representing a wide range of types and degrees of metal pollution. Composite samples of five specimens (males and females combined) per species per site and five specimens per sex per species per site were analyzed for residues of 12 metals in the soft tissues to determine the effects of species and sex, respectively, on variability in the data. Interspecific differences in bioaccumulation were observed for most metals; however, concentrations were frequently correlated between species and the differences could therefore be quantified. Elliptio complanata demonstrated a broader response range to the same exposures than Lampsilis radiata radiata for most metals, suggesting that it may be more sensitive to changes in pollution status. Differences in metal uptake between the sexes were less pronounced than differences between species, and male specimens displayed less variability than females. Consideration of these factors in mussel biomonitoring programs should greatly improve sensitivity and precision.

  8. Headwater locations of U.S. streams tributary to St. Lawrence River basin between western Ohio and eastern New York, excluding Lake Champlain basin

    USGS Publications Warehouse

    Eissler, Benjamin B.

    1979-01-01

    The headwater locations of several thousand U.S. streams tributary to Lakes Ontario and Erie and the St. Lawrence and Niagara Rivers, from the Maumee River in Ohio to the western border of the Lake Champlain basin in New York, including parts of Pennsylvania, are listed by quadrangle. The location of the headwater of each is given with reference to cultural and topographic features. ' Headwater ' in this report is defined as the first site downstream from which the average streamflow is 5 cubic feet per second. The site locations were determined from drainage areas as indicated on topographic maps. The size of the drainage area required to produce an average flow of 5 cubic feet per second was determined from equations, developed separately for each State by regression techniques, that define the relation between streamflow and hydrologic factors of the region. Drainage area and precipitation were factors in the equations for all three States: forest cover was found to be significant in Ohio. (Woodard-USGS)

  9. Meltwater discharge and the triggering of Younger Dryas : new data on the chronology of Champlain Sea transgression in the St-Lawrence River Valley

    NASA Astrophysics Data System (ADS)

    Richard, P.; Occhietti, S.

    2004-05-01

    Accurate chronology of ice retreat is crucial to understand the Ocean-Atmosphere couple at the end of the Pleistocene. The St-Lawrence River Valley is key in this regard, and two sedimentary sequences from Mount Saint-Hilaire, in the middle of the valley, contain a record that sheds new lignt on ice retreat and the penecontemporaneous proglacial marine invasion. Basal AMS-dates on terrestrial plant macrofossils coupled with an extrapolation from the pollen content of underlying postglacial lake sediments at Hemlock Carr (243 m), show that local ice retreat occurred around 11 350 14C yr BP. Cross-dating of such macrofossils (10 510 ± 60 14C yr BP) with shells from marine sediments (~12 200 14C yr BP) catched in the neighbouring Lake Hertel's basin (169 m) show a ca. 1700 14C years difference mainly ascribed to the effect of old, glacially-derived carbon in the upper shallow waters of the Champlain Sea. The pollen-based chronological extrapolation at Lake Hertel indicates that the marine invasion occurred around 11 100 ± 100 14C yr BP. This result supports the chronology based on deep-water invertebrate marine fauna (Rodrigues, 1988). The 14C assessment of the New-England varve chronology (Ridge et al., 1999) is thus confirmed. Deglaciation of the entire Saint-Lawrence River Valley took place within 1000 14C years. The chronology of ice retreat in southern Québec is shortened and made younger. This prompts major revision of all the associated paleohydrological events. Routing of the glacial meltwaters to the North Atlantic was impossible before 11 100 14C yr BP. The abrupt transition from Glacial Lake Candona (ca. 220 m) to the proglacial phase of the Champlain Sea (ca. 190 m) at 11 100 14C yr BP implies an input of glacial meltwater to the ocean estimated at 1500 km3. This may well have affected the thermohaline circulation in the North Atlantic and triggered the Younger Dryas oscillation.

  10. Annual dissolved nitrite plus nitrate and total phosphorous loads for the Susquehanna, St. Lawrence, Mississippi-Atchafalaya, and Columbia River basins, 1968-2004

    USGS Publications Warehouse

    Aulenbach, Brent T.

    2006-01-01

    Annual stream-water loads were calculated near the outlet of four of the larger river basins (Susquehanna, St. Lawrence, Mississippi-Atchafalaya, and Columbia) in the United States for dissolved nitrite plus nitrate (NO2 + NO3) and total phosphorus using LOADEST load estimation software. Loads were estimated for the period 1968-2004; although loads estimated for individual river basins and chemical constituent combinations typically were for shorter time periods due to limitations in data availability. Stream discharge and water-quality data for load estimates were obtained from the U.S. Geological Survey (USGS) with additional stream discharge data for the Mississippi-Atchafalaya River Basin from the U.S. Army Corps of Engineers. The loads were estimated to support national assessments of changes in stream nutrient loads that are periodically conducted by Federal agencies (for example, U.S. Environmental Protection Agency) and other water- and land-resource organizations. Data, methods, and results of load estimates are summarized herein; including World Wide Web links to electronic ASCII text files containing the raw data. The load estimates are compared to dissolved NO2 + NO3 loads for three of the large river basins from 1971 to 1998 that the USGS provided during 2001 to The H. John Heinz III Center for Science, Economics and the Environment (The Heinz Center) for a report The Heinz Center published during 2002. Differences in the load estimates are the result of using the most up-to-date monitoring data since the 2001 analysis, differences in how concentrations less than the reporting limit were handled by the load estimation models, and some errors and exclusions in the 2001 analysis datasets (which resulted in some inaccurate load estimates).

  11. Methane baseline concentrations and sources in shallow aquifers from the shale gas-prone region of the St. Lawrence lowlands (Quebec, Canada).

    PubMed

    Moritz, Anja; Hélie, Jean-Francois; Pinti, Daniele L; Larocque, Marie; Barnetche, Diogo; Retailleau, Sophie; Lefebvre, René; Gélinas, Yves

    2015-04-01

    Hydraulic fracturing is becoming an important technique worldwide to recover hydrocarbons from unconventional sources such as shale gas. In Quebec (Canada), the Utica Shale has been identified as having unconventional gas production potential. However, there has been a moratorium on shale gas exploration since 2010. The work reported here was aimed at defining baseline concentrations of methane in shallow aquifers of the St. Lawrence Lowlands and its sources using δ(13)C methane signatures. Since this study was performed prior to large-scale fracturing activities, it provides background data prior to the eventual exploitation of shale gas through hydraulic fracturing. Groundwater was sampled from private (n = 81), municipal (n = 34), and observation (n = 15) wells between August 2012 and May 2013. Methane was detected in 80% of the wells with an average concentration of 3.8 ± 8.8 mg/L, and a range of <0.0006 to 45.9 mg/L. Methane concentrations were linked to groundwater chemistry and distance to the major faults in the studied area. The methane δ(1)(3)C signature of 19 samples was > -50‰, indicating a potential thermogenic source. Localized areas of high methane concentrations from predominantly biogenic sources were found throughout the study area. In several samples, mixing, migration, and oxidation processes likely affected the chemical and isotopic composition of the gases, making it difficult to pinpoint their origin. Energy companies should respect a safe distance from major natural faults in the bedrock when planning the localization of hydraulic fracturation activities to minimize the risk of contaminating the surrounding groundwater since natural faults are likely to be a preferential migration pathway for methane. PMID:25751654

  12. Gill and head kidney antioxidant processes and innate immune system responses of yellow perch (Perca flavescens) exposed to different contaminants in the St. Lawrence River, Canada.

    PubMed

    Dautremepuits, Claire; Marcogliese, David J; Gendron, Andrée D; Fournier, Michel

    2009-01-15

    Biomarkers of oxidative stress metabolism and the innate immune response were examined in gill and head kidney tissue of wild-caught yellow perch (Perca flavescens) collected from four sites ranging in type and degree of metal pollution in the St. Lawrence River, Quebec, Canada. Sites were ranked as follows: Ile Dorval

  13. Water Quality Monitoring of the Upper St Lawrence River Using Remote Sensor Arrays Placed in a Hydropower Dam Combined with Hydrodynamic Modeling

    NASA Astrophysics Data System (ADS)

    Neff, F.; Sprague, H. M.; Skufca, J. D.; Twiss, M. R.

    2014-12-01

    There are limited long-term data available on the ecological health and environmental state of the Upper St. Lawrence River (CA,US; average discharge 6,910 m3/s). Our research objective is to establish long-term remote water quality monitoring stations in the Moses-Saunders hydroelectric power dam at Massena, New York using a network of sensors. Such a placement of sensors allows for year-round monitoring of water and hence, the ability to measure at times of year and during extreme weather events that previously made monitoring infeasible. The sensor array was installed on 17 June 2014 and draws water from the penstock at a rate of 6-10 L per minute. Sensors in flow through chambers collect data on temperature, turbidity, color dissolved organic material (CDOM), phycocyanin, chlorophyll-a, and specific conductivity at one minute intervals. In combination with a hydrodynamic flow model we are able to hind-cast water movements so that the quality of water passing through the dam can be related to environmental conditions in the river upstream from the sensor array. We conducted field surveys using sensors in a ferry box on a vessel moving upstream (40 km) at a velocity providing a spatial resolution of 100 m and determined that main channel water is more homogenous than water along the shorelines (2 m isopleth) of the river, despite the high turbulence in this river. The sensor array located in the turbine unit nearest the US shore is able to discern tributary inputs for CDOM from the Oswegatchie River (discharge 40-120 m3/s), located 67 km upstream. This research is an important proof-of-concept for installing similar arrays in dams throughout the Great Lakes region and is applicable to smaller rivers containing power dams.

  14. Is the bone tissue of ring-billed gulls breeding in a pollution hotspot in the St. Lawrence River, Canada, impacted by halogenated flame retardant exposure?

    PubMed

    Plourde, Stéphanie Pellerin; Moreau, Robert; Letcher, Robert J; Verreault, Jonathan

    2013-11-01

    Bone metabolism is a tightly regulated process that controls bone remodeling and repair in addition to maintaining circulating calcium and phosphate levels. It has been shown that certain organohalogen contaminants may adversely impact bone tissue metabolism and structure in wildlife species. However, exceedingly few studies have addressed the bone-related effects of organohalogen exposure in birds. The objective of the present study was to investigate the associations between markers of bone metabolism and structural integrity, and concentrations of established and current-use halogenated flame retardants (FRs) in ring-billed gulls (Larus delawarensis) nesting in a known FR hotspot area in the St. Lawrence River (Montreal, Canada). Bone metabolism was assessed using plasma calcium and inorganic phosphate levels, and alkaline phophatase activity, while bone (tarsus; trabecular and cortical sections) structure quality was examined using the percentage of bone tissue comprised in the total bone volume (Bv/Tv) and bone mineral density (BMD). Bv/Tv and BMD of the tarsus tended (not significant) to be positively associated with circulating calcium levels in male ring-billed gulls. Moreover, concentrations of FRs in male bird liver (brominated diphenyl ether (BDE)-154, -183, -201, and -209) and plasma (BDE-209) were negatively correlated with trabecular and cortical BMD of the tarsus. These correlative associations may suggest light demineralization of bone tissue associated with FR exposure in male ring-billed gulls. Present findings provide some evidence that bone (tarsus) metabolism and mineral composition may be impacted in high FR-exposed (mainly to PBDEs) ring-billed gulls breeding in the highly urbanized Montreal region. PMID:24016627

  15. A multi-level biological approach to evaluate impacts of a major municipal effluent in wild St. Lawrence River yellow perch (Perca flavescens).

    PubMed

    Houde, Magali; Giraudo, Maeva; Douville, Mélanie; Bougas, Bérénice; Couture, Patrice; De Silva, Amila O; Spencer, Christine; Lair, Stéphane; Verreault, Jonathan; Bernatchez, Louis; Gagnon, Christian

    2014-11-01

    The development of integrated ecotoxicological approaches is of great interest in the investigation of global concerns such as impacts of municipal wastewater effluents on aquatic ecosystems. The objective of this study was to investigate the effects of a major wastewater municipal effluent on fish using a multi-level biological approach, from gene transcription and enzyme activities to histological changes. Yellow perch (Perca flavescens) were selected based on their wide distribution, their commercial and recreational importance, and the availability of a customized microarray. Yellow perch were sampled upstream of a major municipal wastewater treatment plant (WWTP) and 4 km and 10 km downstream from its point of discharge in the St. Lawrence River (Quebec, Canada). Concentrations of perfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and metals/trace elements in whole body homogenates were comparable to those from other industrialized regions of the world. Genomic results indicated that the transcription level of 177 genes was significantly different (p<0.024) between exposed and non-exposed fish. Among these genes, 38 were found to be differentially transcribed at both downstream sites. Impacted genes were associated with biological processes and molecular functions such as immunity, detoxification, lipid metabolism/energy homeostasis (e.g., peroxisome proliferation), and retinol metabolism suggesting impact of WWTP on these systems. Moreover, antioxidant enzyme activities were more elevated in perch collected at the 4 km site. Biomarkers of lipid metabolism, biosynthetic activity, and aerobic capacities were significantly lower (p<0.05) in fish residing near the outfall of the effluent. Histological examination of the liver indicated no differences between sites. Correlations between PFAS, PBDE, and metal/trace element tissue concentrations and markers of peroxisomal proliferation, oxidative stress, and retinoid metabolism were found at the gene and cellular levels. Present results suggest that relating transcriptomic analyses to phenotypic responses is important to better understand impacts of environmental contamination on wild fish populations. PMID:25137380

  16. Fault stability and CO2 storage in the Early Paleozoic sedimentary basin of the St. Lawrence Lowlands (Quebec, Canada): insight from coupled reservoir-geomechanical modeling

    NASA Astrophysics Data System (ADS)

    Konstantinovskaya, E.; Rutqvist, J.; Malo, M.

    2013-12-01

    A coupled reservoir-geomechanical (TOUGH-FLAC) modeling is applied to evaluate the potential shear failure along pre-existing high-angle normal faults and tensile failure in the caprock units (Utica Shale and Lorraine Group) associated with CO2 injection into the sandstone reservoir (Covey Hill Formation) of the Early Paleozoic sedimentary basin in the St. Lawrence Lowlands (Quebec, Canada). Field and subsurface data are used to estimate sealing properties of the faults. The spatial variations in fluid pressure, effective minimum horizontal stress and shear strain are calculated for different injection rates using a simplified 2D geological model of the Becancour area between Montreal and Quebec City. The simulation results show that the likelihood of reactivating two reservoir-bounding faults (Yamaska and Champlain Faults) strongly depends on reservoir pressure at the faults, which in turn depends on injection rate, hydrological properties of aquifers and the distance between the faults and the injection well. The Yamaska Fault, which is located closer (1.5 km) to the injection zone is easier reactivated than the more distant (4.4 km) Champlain Fault. In addition, fault permeability affects the timing, localization, rate and length of fault shear slip. If the fault is sealing, shear slip occurs later in time and it is localized along the fault segment (230 m) below the caprock units. If the fault is permeable, the fault reactivation starts earlier and shear slip is nucleated along the fault segment (50 m) in the caprock units subsequently progressing up to the surface. Sealing fault behaviour causes asymmetric fluid pressure build-up and lateral migration of CO2 plume away from the closer-to-injection Yamaska fault that reduces the overall risk of CO2 leakage along faults. The fluid-pressure induced tensile fracturing postdates shear failure along faults; it occurs only under extremely high reservoir pressure as a result of high injection rates, with fracturing being localized below the caprock units, which remain intact preventing upward CO2 migration. Fig. 1. Changes in effective shear strain occurred around the injection zone and along the Yamaska Fault during subsequent steps of experimental run, low injection rate, sealing fault behaviour. Fault slip occurs after 22.5 years of continued injection.

  17. Intra-annual variability of water quality and phytoplankton in the North Fork of the St. Lucie River Estuary, Florida (USA): a quantitative assessment

    NASA Astrophysics Data System (ADS)

    Millie, D. F.; Carrick, H. J.; Doering, P. H.; Steidinger, K. A.

    2004-09-01

    Water quality and phytoplankton were examined within the North Fork of the St. Lucie River Estuary, Florida (USA) from March 2000 to March 2001. Alterations in water-quality parameters and phytoplankton assemblages mirrored salinity regimes resulting from the 'wet'/'dry' seasonality of south Florida. Salinity was greatest during the 'dry', winter months whereas water temperature and nitrogen and phosphorus concentrations were greatest during the 'wet', summer months. A seasonal dissimilarity in phytoplankton occurred; cell abundance of cyanobacterial picoplankton ( Synechocystis sp., Synechococcus sp.) and a diatom ( Skeletonema costatum (Greville) Cleve) and cell carbon of a dinoflagellate ( Gyrodinium sp.) and S. costatum were greatest during summer whereas abundance of chrysophytes ( Chrysochromulina parva Lackey, Chromulina sp.) and carbon of dinoflagellates ( Gymnodinium spp., Heterocapsa rotundata (Lohmann) Hansen) and a diatom ( Cyclotella sp.) were greatest during winter. Water-column chlorophyll a concentrations reached up to 29 μg L -1 and were negatively associated with salinity. Diatom chlorophyll comprised the majority and at times, greater than 90% of the total chlorophyll a. Picoplanktonic cyanobacteria comprised up to 5% and 1.4% of total phytoplankton carbon and chlorophyll a, respectively throughout the estuary; as such, its impact on overall assemblage rate processes and system-level function appeared minimal. Sediment and whole-water incubations confirmed the presence of heterotrophic dinoflagellates within the estuary. Dissolved oxygen concentrations did not correspond with total chlorophyll a concentrations and salinity, indicating that hypoxia within bottom waters during summer was not solely attributable to phytoplankton biomass or water-column stratification but likely, a result of multiple, interacting physical/chemical and biological factors.

  18. Detection and quantitation of benzo(a)pyrene-DNA adducts in brain and liver tissues of Beluga whales (Delphinapterus leucas) from the St. Lawrence and Mackenzie Estuaries

    SciTech Connect

    Shugart, L.R.

    1988-01-01

    It should be noted that there are few analytical techniques available for the detection and quantitation of chemical adducts in the DNA of living organisms. The reasons for this are: the analytical technique often has to accommodate the unique chemical and/or physical properties of the individual chemical or its metabolite; the percentage of total chemical that becomes most of the parent compound is usually detoxified and excreted; not all adducts that form between the genotoxic agent and DNA are stable or are involved in the development of subsequent deleterious events in the organism; and the amount of DNA available for analysis is often quite limited. 16 refs., 1 tab.

  19. Contribution of active and passive acoustics to study oceanographic processes feeding whales in a critical habitat of the St. Lawrence Estuary

    NASA Astrophysics Data System (ADS)

    Simard, Yvan; Roy, Nathalie; Simard, Yvan; Cotté, Cédric

    2001-05-01

    The head of the main channel of the continent in eastern Canada is the site of particular oceanographic processes that are responsible for the creation of a persistent feeding ground regularly visited by baleen whales from the Atlantic for centuries. Multifrequency acoustics coupled with ADCP and hydrographic measurements has been used to map the krill and capelin aggregations in 3D and visualize their local concentration process under tidal forcing and upwelling at the channel head. The krill scattering layers, pumped into the area by the strong two-layer estuarine circulation, appear to be concentrated during flood by tidal currents forced against the slopes and upwelling, to which depth-keeping krill is reacting by swimming down. Capelin also tends to concentrate on slopes and neighboring shallows. This highly recurrent process generates rich patches that are contributing with the mean circulation to make this area the richest krill aggregation in Northwest Atlantic. This critical habitat is located in a major continental seaway. Passive acoustics techniques are explored to locate whale calls and map the use of this area in continuing months, especially by blue and fin whales, with the aim of understanding their movements to improve their protection.

  20. PBDEs and PCBs in the liver of the St Lawrence Estuary beluga (Delphinapterus leucas): a comparison of levels and temporal trends with the blubber.

    PubMed

    Raach, Meriem; Lebeuf, Michel; Pelletier, Emilien

    2011-03-01

    Due to their lipophilic properties, persistent organic pollutants (POPs) are commonly assessed using the blubber of marine mammals. However, these chemicals are also accumulating in other tissues including the liver. Some pollutants, namely perfluorinated alkyl acids, are found predominately in the liver and blood of marine mammals, and thus monitored in those tissues. This raises the question whether any tissue would represent an identical trend of POPs in the SLE beluga. The current study reports the first temporal trends of PBDEs and PCBs in the liver of 65 SLE belugas. Neither ∑₇PBDEs nor major individual PBDE-homolog group concentrations showed significant trends between 1993 and 2007. Also, ∑₃₂PCBs did not change over years, although, tetra-, penta- and hepta-PCB decreased by 7.1, 6.8 and 8.5%, respectively, in males, whereas tetra-, penta- and octa-PCBs declined by 11, 12 and 12.9%, respectively, in females. In order to compare the distribution of POPs between liver and blubber, a lipid normalised concentration ratio R (blubber/liver) for PBDEs and PCBs was calculated for each individual beluga. For all PBDE and several PCB homolog groups, mean R values were not statistically different from unity indicating that the partitioning of these POPs is governed by the tissue lipid-content. Temporal trends of R ratios of PBDEs and PCBs were also examined. There were generally no significant temporal trends except for PBDEs in males where R increased in average by 12.7 ± 2.9% yearly. The stratification of the blubber into a metabolically active (inner) and less active layers (outer blubber) may result in a slower response time of the blubber (full depth) than the liver to the recent change of contamination in the environment and explain the time trend differences between both tissues. This study suggests that the liver is more representative of recent exposure to lipophilic contaminants. PMID:21270998

  1. Maturity, size at age and predator-prey relationships of winter skate Leucoraja ocellata in the southern Gulf of St Lawrence: potentially an undescribed endemic facing extirpation.

    PubMed

    Kelly, J T; Hanson, J M

    2013-03-01

    The goals of this study were to document the size and age structure, size at maturity, ovarian fecundity and diet of the endangered population of winter skate Leucoraja ocellata that resides in the southern Gulf of St Lawrence (SGSL). The maximum size observed for SGSL L. ocellata was 68 cm total length (LT ) but >99% of animals caught were <60 cm LT . Fifty per cent of male and female L. ocellata were fully mature at 40 and 42 cm LT , respectively, age c. 5 years. The oldest individual caught was age 11 years, but 98% of the 561 individuals examined were ≤age 8 years, indicating a short reproductive life span. Ovarian fecundity was low; no more than 29 ova >10 mm diameter were ever observed. At 40 cm LT , the diet changed from one dominated by shrimp Crangon septemspinosa and gammarid amphipods to one dominated by fishes (mainly sand lance Ammodytes spp. and rainbow smelt Osmerus mordax) and Atlantic rock crab Cancer irroratus. Sufficient differences were observed between SGSL L. ocellata and other populations in their size-at-maturity pattern and maximum size to propose the taxonomic re-evaluation of the population. PMID:23464554

  2. Eutrophication of the St. Lawrence Great Lakes

    USGS Publications Warehouse

    Beeton, Alfred M.

    1965-01-01

    Lakes Huron, Michigan, and Superior are classified as oligotrophic lakes on the basis of their biological, chemical, and physical characteristics. Lake Ontario, although rich in nutrients, is morphometrically oligotrophic or mesotrophic because of its large area of deep water. Lake Erie, the most productive of the lakes and the shallowest, is eutrophic. Several changes commonly associated with eutrophication in small lakes have been observed in the Great Lakes. These changes apparently reflect accelerated eutrophication in the Great Lakes due to man's activity. Chemical data compiled from a number of sources, dating as early as 1854, indicate a progressive increase in the concentrations of various major ions and total dissolved solids in all of the lakes except Lake Superior. The plankton has changed somewhat in Lake Michigan and the plankton, benthos, and fish populations of Lake Erie are greatly different today from those of the past. An extensive area of hypolimnetic water of Lake Erie has developed low dissolved oxygen concentrations in late summer within recent years.

  3. Distribution, abundance, and range of the round goby, Apollina melanostoma, in the Duluth-Superior Harbor and St. Louis River estuary, 1998-2004

    USGS Publications Warehouse

    Bergstrom, M.A.; Evrard, L.M.; Mensinger, A.F.

    2008-01-01

    Round gobies were first discovered in the Duluth-Superior Harbor, Lake Superior, in 1995. Anecdotal sightings by anglers and others suggested that the infestation was growing and expanding; however, direct evidence of the distribution and expansion rate in the harbor was largely unknown. Distribution and range of the round goby, Apollonia melanostoma, (formerly Neogobius melanostomus) was assessed using bottom trawl sampling throughout the Duluth-Superior Harbor, and portions of the lower St. Louis River from 1998 to 2004. Previous to 1998, round gobies only were reported to occupy the harbor between the two shipping entries (river kilometer 1 to 7). By 2004, they expanded throughout the harbor and upstream to river kilometer 13, but remained absent in western Lake Superior. The number of round gobies captured per 5 minutes of trawling (catch per unit effort, CPUE) increased from less than 1 fish in 1998 to an average 5.4 ?? 1.2 SE fish in 2004, indicating a large increase in the population. The median yearly fish total length varied from 56.0 to 81.5 mm and wet weight varied from 2.3 to 7.0 g. As nest guarding male round gobies were located in rocky habitats inaccessible to trawling, the initial years were dominated by female round gobies with a 16:1 female to male ratio, but by 2002 the maximum ratio was 2:1. The ratio change may be indicative of the increasing population forcing males from their preferred rocky habitat onto open substrates that were more accessible to trawling.

  4. Introduction to Estuaries

    EPA Science Inventory

    Estuaries, although minor geographical features at the global scale, have major importance for society and the world’s economies. This chapter introduces estuaries by presenting an overview of definitions, origins, physical, chemical and ecological attributes, and the interaction...

  5. Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary

    NASA Astrophysics Data System (ADS)

    Casper, A. F.

    2005-05-01

    The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

  6. Three dimensional water quality modeling of a shallow subtropical estuary.

    PubMed

    Wan, Yongshan; Ji, Zhen-Gang; Shen, Jian; Hu, Guangdou; Sun, Detong

    2012-12-01

    Knowledge of estuarine hydrodynamics and water quality comes mostly from studies of large estuarine systems. The processes affecting algae, nutrients, and dissolved oxygen (DO) in small and shallow subtropical estuaries are relatively less studied. This paper documents the development, calibration, and verification of a three dimensional (3D) water quality model for the St. Lucie Estuary (SLE), a small and shallow estuary located on the east coast of south Florida. The water quality model is calibrated and verified using two years of measured data. Statistical analyses indicate that the model is capable of reproducing key water quality characteristics of the estuary within an acceptable range of accuracy. The calibrated model is further applied to study hydrodynamic and eutrophication processes in the estuary. Modeling results reveal that high algae concentrations in the estuary are likely caused by excessive nutrient and algae supplies in freshwater inflows. While algal blooms may lead to reduced DO concentrations near the bottom of the waterbody, this study indicates that stratification and circulation induced by freshwater inflows may also contribute significantly to bottom water hypoxia in the estuary. It is also found that high freshwater inflows from one of the tributaries can change the circulation pattern and nutrient loading, thereby impacting water quality conditions of the entire estuary. Restoration plans for the SLE ecosystem need to consider both a reduction of nutrient loading and regulation of the freshwater discharge pattern. PMID:23122270

  7. Learning Lessons from Estuaries

    ERIC Educational Resources Information Center

    Schnittka, Christine

    2006-01-01

    There is something that draws all people to the sea and especially to the fertile estuaries that nuzzle up to its shores. An estuary serves as both a nursery and a grave for sea creatures. If life evolved from some primordial sea, it may well have been an estuary--a place where ocean and rivers meet and fresh and salty waters mingle in the…

  8. Estuary Data Mapper

    EPA Science Inventory

    The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools to support decision-making. To facilita...

  9. Biogeochemistry of Estuaries

    NASA Astrophysics Data System (ADS)

    Burdige, David J.

    2007-12-01

    Whether you are interested in material flux from the continents to the oceans or whether the oysters set down in front of you at a waterfront restaurant may have come from polluted waters, we know estuaries are important places. However, anyone attempting to summarize and synthesize the long and rich literature of estuarine research is presented with a daunting task. This is because beyond the concept of an estuary being the transition zone where ``fresh water meets seawater,'' the exact definition of an estuary is not uniformly agreed upon by scientists in this field. Also, estuaries-regardless of how they are defined-tend to be highly heterogeneous, in both space and time. Against this backdrop, Thomas Bianchi's Biogeochemistry of Estuaries successfully tackles its subject matter and is an exciting addition to the field of estuarine research.

  10. Metaproteomics of aquatic microbial communities in a deep and stratified estuary.

    PubMed

    Colatriano, David; Ramachandran, Arthi; Yergeau, Etienne; Maranger, Roxane; Gélinas, Yves; Walsh, David A

    2015-10-01

    Here we harnessed the power of metaproteomics to assess the metabolic diversity and function of stratified aquatic microbial communities in the deep and expansive Lower St. Lawrence Estuary, located in eastern Canada. Vertical profiling of the microbial communities through the stratified water column revealed differences in metabolic lifestyles and in carbon and nitrogen processing pathways. In productive surface waters, we identified heterotrophic populations involved in the processing of high and low molecular weight organic matter from both terrestrial (e.g. cellulose and xylose) and marine (e.g. organic compatible osmolytes) sources. In the less productive deep waters, chemosynthetic production coupled to nitrification by MG-I Thaumarchaeota and Nitrospina appeared to be a dominant metabolic strategy. Similar to other studies of the coastal ocean, we identified methanol oxidation proteins originating from the common OM43 marine clade. However, we also identified a novel lineage of methanol-oxidizers specifically in the particle-rich bottom (i.e. nepheloid) layer. Membrane transport proteins assigned to the uncultivated MG-II Euryarchaeota were also specifically detected in the nepheloid layer. In total, these results revealed strong vertical structure of microbial taxa and metabolic activities, as well as the presence of specific "nepheloid" taxa that may contribute significantly to coastal ocean nutrient cycling. PMID:26223443

  11. Tidal fronts in estuaries

    NASA Astrophysics Data System (ADS)

    Pelegrí, J. L.

    1988-07-01

    Three estuaries in Wales were carefully surveyed during flood conditions. They are characterized by the intrusion of a tidal front. In one estuary the front retreats after maximum flood velocities and stratification persists during the whole tidal cycle. In the other estuaries the flood erases the initial stratification causing partially or totally mixed situations. A tidal Froude number is employed to characterize the evolution of stratification during the flood. It is shown that gravity current theory approximately holds under well-stratified conditions in a region near to, but not too close to, the head of the front.

  12. An interview with Peter Lawrence.

    PubMed

    Vicente, Catarina

    2016-01-15

    Peter Lawrence, FRS, is a fly geneticist based at the Department of Zoology at the University of Cambridge. During his illustrious career he has carried out pioneering work on pattern formation and polarity, and his contributions have been recognised by many honours, including the Prince of Asturias prize with Gines Morata and election to the Royal Swedish Academy of Sciences. He is also an outspoken critic of the current scientific system and particularly how it affects young scientists. We recently had the opportunity to chat with Peter, and we asked him about the influence of his mentor Sir V. B. Wigglesworth, writing his first grant at age 65 and his time as an editor of Development. PMID:26786208

  13. LAWRENCE RISK-BASED AIR SCREENING

    EPA Science Inventory

    The pediatric asthma rate in the city of Lawrence is the highest in the state of Massachusetts. This project will evaluate whether the cumulative risks due to the air pollution in Lawrence is contributing to the high asthma rates and other respiratory problems. The project will...

  14. 14. Historic American Buildings Survey PHOTOCOPY OF EVERETT MILLS, LAWRENCE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Historic American Buildings Survey PHOTOCOPY OF EVERETT MILLS, LAWRENCE, MASS., INSURANCE SURVEY DRAWING n. d. From the collection of Factory Mutual Insurance Company, Norwood, Mass. - Lawrence Machine Shop, Union & Canal Streets, Lawrence, Essex County, MA

  15. Relationship between Estuary Shape and Hydrodynamics in Alluvial Estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, J. I. A.; Savenije, H. H. G.

    2012-04-01

    Generally research on morphology and hydrodynamics in estuaries is done separately: the hydrodynamics is studied for a given geometry, and the morphology is studied for given hydrodynamics. 3-D morphological models indeed integrate morphology and hydrodynamics, but this is forward modelling, not aimed at understanding why certain relations in nature exist. Until now, little research has been done on identifying the relationship between estuary shape and hydrodynamics in alluvial estuaries. In this research, the aim is to develop an analytical model to relate tidal characteristics and flood discharge signatures to estuary shape. By this, engineers would be able to estimate flood discharge characteristics in an estuary from estuary shape indicators. This could be very useful to predict flood the discharge in ungauged estuaries. Data from 16 estuaries around the world have been analyzed to develop and test the analytical relationship. From the analysis, it shows that the shape of estuaries indeed depends on a characteristic flood discharge, the tidal range, the depth and the celerity of the tidal wave. Besides that, other parameter such as sediment sizes will also be included into analysis which also affects the morphodynamics of the estuary. In order to verify the accuracy and reliability of the model, more data on the morphology and hydrodynamics are required. Thus, in this research, about 18 estuaries in Malaysia will be studied and included into the analysis to validate the model. Meanwhile, existing available data from other estuaries worldwide will be collected simultaneously to expend the database. Keywords: morphology, hydrodynamics, estuary shape, tidal range, wave celerity, analytical model

  16. DELAWARE ESTUARY PCB MODEL

    EPA Science Inventory

    The Delaware River Basin Commission recently completed the first phase of a program to develop and implement Total Maximum Daily Loads (TMDLs) for toxic pollutants for the Delaware Estuary. This complex body of water extends from the head of tide at Trenton, NJ (River Mile 133.2...

  17. Lawrence Berkeley Lab Indexing Toolbox

    Energy Science and Technology Software Center (ESTSC)

    2003-09-08

    The Lawrence Berkeley Lab Indexing Toolbox is intended to be used in the context of X-ray crystallography experiments involving biological macromolecules. Macromolecules such as proteins form 3-dimensional periodic arrays (crystal) which in turn lead to lattice-like diffraction patterns when the crystal sample is irradiated with collimated X-rays from a synchrotron or other X-ray source. Once the diffraction pattern is captured on an imaging device the next step is to deduce the periodic nature of themore » crystal sample, along with its internal symmetry. this analysis, known as "indexing" is a well-studied problem. However, there are no other implementations designed to operate in an automated setting, in which the human experimentalist is not prosent to manually verify the results of indexing. In particular LABELIT uses three novel algorithms to facilitate automation: a more robust way to verify the position of the incident X-ray beam on the image, a better way to verify that the deduced lattice is consistent with the observed crystal lattice, and new method to deduce the internal symmetry from measurements of the lattice. Moreover, the algorithms are implemented in a Python framework that permits indexing to fail (in rare cases) without crashing the program, thus allowing the software to be incorporated in robotic systems where unattended operation is expected. It will be especially useful for high throughput operations at snychrotron beamlines.« less

  18. Lawrence Livermore National Laboratory 2007 Annual Report

    SciTech Connect

    Chrzanowski, P; Walter, K

    2008-04-25

    Lawrence Livermore National Laboratory's many outstanding accomplishments in 2007 are a tribute to a dedicated staff, which is shaping the Laboratory's future as we go through a period of transition and transformation. The achievements highlighted in this annual report illustrate our focus on the important problems that affect our nation's security and global stability, our application of breakthrough science and technology to tackle those problems, and our commitment to safe, secure, and efficient operations. In May 2007, the Department of Energy (DOE) awarded Lawrence Livermore National Security, LLC (LLNS), a new public-private partnership, the contract to manage and operate the Laboratory starting in October. Since its inception in 1952, the Laboratory had been managed by the University of California (UC) for the DOE's National Nuclear Security Administration (NNSA) and predecessor organizations. UC is one of the parent organizations that make up LLNS, and UC's presence in the new management entity will help us carry forward our strong tradition of multidisciplinary science and technology. 'Team science' applied to big problems was pioneered by the Laboratory's co-founder and namesake, Ernest O. Lawrence, and has been our hallmark ever since. Transition began fully a year before DOE's announcement. More than 1,600 activities had to be carried out to transition the Laboratory from management by a not-for-profit to a private entity. People, property, and procedures as well as contracts, formal agreements, and liabilities had to be transferred to LLNS. The pre-transition and transition teams did a superb job, and I thank them for their hard work. Transformation is an ongoing process at Livermore. We continually reinvent ourselves as we seek breakthroughs that impact emerging national needs. An example is our development in the late 1990s of a portable instrument that could rapidly detect DNA signatures, research that started with a view toward the potential threat of terrorist use of biological weapons. As featured in our annual report, activities in this area have grown to many important projects contributing to homeland security and disease prevention and control. At times transformation happens in large steps. Such was the case when nuclear testing stopped in the early 1990s. As one of the nation's nuclear weapon design laboratories, Livermore embarked on the Stockpile Stewardship Program. The objectives are to ensure the safety, security, and reliability of the nation's nuclear weapons stockpile and to develop a science-based, thorough understanding of the performance of nuclear weapons. The ultimate goal is to sustain confidence in an aging stockpile without nuclear testing. Now is another time of major change for the Laboratory as the nation is resizing its nuclear deterrent and NNSA begins taking steps to transform the nuclear weapons complex to meet 21st-century national security needs. As you will notice in the opening commentary to each section of this report, the Laboratory's senior management team is a mixture of new and familiar faces. LLNS drew the best talent from its parent organizations--Bechtel National, UC, Babcock & Wilcox, the Washington Group Division of URS, and Battelle--to lead the Laboratory. We are honored to take on the responsibility and see a future with great opportunities for Livermore to apply its exceptional science and technology to important national problems. We will work with NNSA to build on the successful Stockpile Stewardship Program and transform the nation's nuclear weapons complex to become smaller, safer, more secure, and more cost effective. Our annual report highlights progress in many relevant areas. Laboratory scientists are using astonishing computational capabilities--including BlueGene/L, the world's fastest supercomputer with a revolutionary architecture and over 200,000 processors--to gain key insights about performance of aging nuclear weapons. What we learn will help us sustain the stockpile without nuclear testing. Preparations are underway to start experiments at the National Ignition Facility (NIF), the world's largest laser. They will help us resolve the most important questions we still have about nuclear weapons performance. Future NIF experiments will also explore the promise of an essentially inexhaustible source of clean energy from nuclear fusion. In addition, we have begun the process of eliminating significant quantities of special nuclear materials from the Livermore site. We will carry forward Livermore's tradition of exceptional science and technology. This is the S&T that led to the design and construction of NIF and leadership in an international consortium that is developing the Gemini Planet Imager. When the Imager comes on line in 2010 at an observatory in Chile, the Imager will bring into sharp focus planets that are 30 to 150 light years from our solar system.

  19. THREE-DIMENSIONAL MODELING OF COHESIVE SEDIMENT TRANSPORT IN A PARTIALLY STRATIFIED MICRO-TIDAL ESTUARY TO ASSESS EFFECTIVENESS OF SEDIMENT TRAPS

    EPA Science Inventory

    The three-dimensional (3D) finite difference model Environmental Fluid Dynamics Code (EFDC) was used to simulate the hydrodynamics and sediment transport in a partially stratified micro-tidal estuary. The estuary modeled consisted of a 16-km reach of the St. Johns River, Florida,...

  20. Ecology of estuaries

    SciTech Connect

    Kennish, M.J. )

    1992-01-01

    Ecology of Estuaries: Anthropogenic Effects represents the most definitive and comprehensive source of reference information available on the human impact on estuarine ecosystems. The book discusses both acute and insidious pollution problems plaguing these coastal ecotones. It also provides a detailed examination of the deleterious and pervasive effects of human activities on biotic communities and sensitive habitat areas in estuaries. Specific areas covered include organic loading, oil pollution, polynuclear aromatic hydrocarbons, chlorinated hydrocarbons, heavy metals, dredging and dredge-spoil disposal, radionuclides, as well as other contaminants and processes. The diverse components of these anthropogenic influences are assembled in an organized framework and presented in a clear and concise style that will facilitate their understanding.

  1. Ecology of estuaries

    SciTech Connect

    Kennish, M.J.

    1986-01-01

    This book is a summary of information available on estuarine ecology, that reviews concepts and problems of estuaries and assesses the value of these coastal systems. It investigates such topics as water circulation and mixing, trace elements, nutrients, organic matter, and sedimentary processes, with reviews on more than two decades of intense study. Chapters reflect contributions from a variety of interdisciplinary sciences including botany, chemistry, ecology, geology, physics, and zoology.

  2. Toward delisting of the water quality beneficial use impairment in the St. Louis River, MN: A monitoring approach

    EPA Science Inventory

    Water quality in the St. Louis River Estuary (SLRE), a great lakes area of concern (AOC), is improving. A significant leap forward followed the opening of the Western Lake Superior Sanitary District in 1978. However, desire for continued improvement throughout the estuary was the...

  3. Working Papers from the Lawrence Literacy Coalition.

    ERIC Educational Resources Information Center

    Kalmar, Tomas Mario; de Tal, Fulano

    Four papers concerning the Lawrence (Massachusetts) Literacy Coalition, a consortium of 12 two- and four-year colleges supporting adult literacy activities in the region, are presented. The first paper offers an overview of the coalition, including the reasons for its formation, a definition of literacy, the scope of the coalition's work, and…

  4. Struggle for the Soul: John Lawrence Childs

    ERIC Educational Resources Information Center

    Stallones, Jared

    2010-01-01

    John Lawrence Childs was born in Eau Claire, Wisconsin on January 11, 1889, the second child of John Nelson Childs and Helen Janette (Nettie) Smith. In childhood Childs absorbed the values of industry, democracy, and a traditional, but socially conscious, religion. Childs was a Methodist and an intensely private person not given to talking about

  5. Struggle for the Soul: John Lawrence Childs

    ERIC Educational Resources Information Center

    Stallones, Jared

    2010-01-01

    John Lawrence Childs was born in Eau Claire, Wisconsin on January 11, 1889, the second child of John Nelson Childs and Helen Janette (Nettie) Smith. In childhood Childs absorbed the values of industry, democracy, and a traditional, but socially conscious, religion. Childs was a Methodist and an intensely private person not given to talking about…

  6. Recruitment and origin of penaeid prawn postlarvae in two South-east African estuaries

    NASA Astrophysics Data System (ADS)

    Forbes, A. T.; Cyrus, D. P.

    1991-09-01

    Input of postlarval stages into the penaeid prawn stocks of Natal, South Africa, was investigated by monitoring immigration into the St Lucia and Kosi estuaries. Five species, Penaeus japonicus Bate, P. indicus Milne Edwards, P. semisulcatus de Haan, P. monodon Fabricius and Metapenaeus monoceros (Fabricius) were recorded. Recruitment into the more northerly Kosi estuary, where offshore conditions are influenced by the south-flowing Agulhas Current, was totally dominated by P. japonicus. At St Lucia, at the northern end of the Tugela Bank, similar numbers of P. japonicus and P. indicus were recorded as well as smaller numbers of the other three species. The differences imply that the Tugela Bank provides the major postlarval input of commercially important species to St Lucia and suggests a greater degree of isolation of the Natal penaeid prawn populations than previously thought.

  7. Lawrence Livermore National Laboratory Environmental Report 2014

    SciTech Connect

    Jones, H. E.; Bertoldo, N. A.; Blake, R. G.; Buscheck, W. M.; Byrne, J. G.; Cerruti, S. J.; Bish, C. B.; Fratanduono, M. E.; Grayson, A. R.; MacQueen, D. H.; Montemayor, W. E.; Ottaway, H. L.; Paterson, L. E.; Revelli, M. A.; Rosene, C. A.; Swanson, K. A.; Terrill, A. A.; Wegrecki, A. M.; Wilson, K. R.; Woollett, J. S.

    2015-09-29

    The purposes of the Lawrence Livermore National Laboratory Environmental Report 2014 are to record Lawrence Livermore National Laboratory’s (LLNL’s) compliance with environmental standards and requirements, describe LLNL’s environmental protection and remediation programs, and present the results of environmental monitoring at the two LLNL sites—the Livermore Site and Site 300. The report is prepared for the U.S. Department of Energy (DOE) by LLNL’s Environmental Functional Area. Submittal of the report satisfies requirements under DOE Order 231.1B, “Environment, Safety and Health Reporting,” and DOE Order 458.1, “Radiation Protection of the Public and Environment.”

  8. Lawrence Berkeley Laboratory 1993 Site Environmental Report

    SciTech Connect

    Not Available

    1994-05-01

    This annual Site Environmental Report summarizes Lawrence Berkeley Laboratory`s (LBL`s) environmental activities in calendar year (CY) 1993. The purpose of this report is to characterize site environmental management performance, confirm compliance status with environmental standards and requirements, and highlight significant programs and efforts. Its format and content are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  9. Dr. Tom Lawrence: a life in chiropractic

    PubMed Central

    Keating, Joseph C

    2005-01-01

    He dwelt within the chiropractic orbit from the cradle to the grave. Second-generation chiropractor Tom Lawrence was a successful professional and family man who followed in his father’s footsteps and fought the good fight to improve chiropractic within his state and nation. His passing closes a chapter of living memory of the middle years of the first chiropractic century. PMID:17549212

  10. The geothermal program at Lawrence Berkeley Laboratory

    SciTech Connect

    Lippmann, M.J.

    1987-06-01

    The main purpose of the geothermal program at Lawrence Berkeley Laboratory is to develop, improve and validate methods and instrumentation to: (1) determine geothermal reservoir parameters; (2) detect and characterize reservoir fractures and boundaries; and (3) identify and evaluate the importance of reservoir processes. The ultimate objective of the program, which includes field, theoretical and modeling activities, is to advance the state-of-the-art for characterizing geothermal systems and evaluating their productive capacity and longevity under commercial exploitation.

  11. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  12. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection - March 2011

    EPA Science Inventory

    We examined the role of the oceanestuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO w...

  13. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  14. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection - March 2011

    EPA Science Inventory

    We examined the role of the ocean–estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO w...

  15. Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  16. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  17. Life sciences: Lawrence Berkeley Laboratory, 1988

    SciTech Connect

    Not Available

    1989-07-01

    Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs.

  18. Spatial and Temporal Variation of Physico-chemical Parameters in the Merbok Estuary, Kedah, Malaysia

    PubMed Central

    Fatema, Kaniz; Wan Maznah, WO; Isa, Mansor Mat

    2014-01-01

    In this study, factor analysis (FA) was applied to extract the hidden factors responsible for water quality variations during both wet and dry seasons. Water samples were collected from six sampling stations (St. 1 Lalang River, St. 2 Semeling River, St. 3 Jagung River, St. 4 Teluk Wang River, St. 5 Gelam River and St. 6 Derhaka River) in the Merbok estuary, Malaysia from January to December 2011; the samples were further analysed in the laboratory. Correlation analysis of the data sets showed strong correlations between the parameters. Nutrients such as nitrate (NO3−), nitrite (NO2−), ammonia (NH3) and phosphate (PO43−) were determined to be critical indicators of water quality throughout the year. Influential water quality parameters during the wet season were conductivity, salinity, biochemical oxygen demand (BOD), dissolved oxygen (DO) and chlorophyll a (Chla), whereas total suspended solid (TSS) and pH were critical water quality indicators during the dry season. The Kruskal-Wallis H test showed that water quality parameters were significantly different among the sampling months and stations (p<0.05), and Mann-Whitney U tests further revealed that the significantly different parameters were temperature, pH, DO, TSS, NO2− and BOD (p<0.01), whereas salinity, conductivity, NO3−, PO43−, NH3 and Chla were not significantly different (p>0.05). Water quality parameters in the estuary varied on both temporal and spatial scales and these results may serve as baseline information for estuary management, specifically for the Merbok estuary. PMID:27073596

  19. EXHIBIT OF EMPACT ESTUARY MONITORING HANDBOOKS

    EPA Science Inventory

    Related EMPACT documents were displayed at the National Estuary Day Celebration held in Washington, DC, September 30-Octuber 4, 2002. The estuary monitoring technology transfer handbooks displayed were prepared based on information and monitoring technologies developed from selec...

  20. PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY

    EPA Science Inventory

    PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY The main objective of this study is to develop criteria for eelgrass habitat establishment and persistence within the Peconic Estuary utilizing various environmental analyses. The Program evaluated water and sediment quality data to...

  1. Application of microwave radiometers for wetlands and estuaries monitoring

    SciTech Connect

    Shutko, A.; Haldin, A.; Novichikhin, E.

    1997-06-01

    This paper presents the examples of experimental data obtained with airborne microwave radiometers used for monitoring of wetlands and estuaries located in coastal environments. The international team of researchers has successfully worked in Russia, Ukraine and USA. The data presented relate to a period of time between 1990 and 1995. They have been collected in Odessa Region, Black Sea coast, Ukraine, in Regions of Pittsville and Winfield, Maryland, USA, and in Region of St. Marks, Florida, USA. The parameters discussed are a soil moisture, depth to a shallow water table, vegetation index, salinity of water surface.

  2. Obituary: Lawrence Hugh Aller, 1913-2003

    NASA Astrophysics Data System (ADS)

    Kaler, James B.

    2003-12-01

    The announcement still lies in my inbox: ``Lawrence Aller died last Sunday." On 16 March 2003, one of the world's fine astronomers passed away at the age of 89, leaving behind a legacy that will ripple as long as there are students of the celestial science, one that incorporated observation, theory, education, care, decency, and kindness. Lawrence was born in the humblest of conditions in Tacoma, Washington, on 24 September 1913. His mother, Lella (Belle) Allen, was a homemaker and his father Leslie Aller, was an occassional printer and gold prospector who thought that the use of the mind was a waste of time. With fierce persistence and dedication, Lawrence pulled off a feat that would probably not be possible now: getting into college without having finished high school, the result of being dragged to work in his father's primitive gold mining camp. His interest, sparked by leaflets from the Astronomical Society of the Pacific and by Russell, Dugan, and Stewart's venerable textbook, led him to a correspondence, and finally a meeting, with Donald Menzel of Harvard, who persuaded the admissions director of the University of California at Berkeley to admit him in 1932. From there, Lawrence went on to graduate school at Harvard and the Harvard Society of Fellows, where he studied with Menzel and developed his interest in stellar and nebular astronomy. After working in the War effort, he made his professorial debut at Indiana University, where he stayed until 1948 before leaving for the University of Michigan. Residing there for the next 14 years, he established his research reputation and helped develop the Michigan graduate program. In 1962, the opportunity arose to return to California, to UCLA, where he again was instrumental in founding a PhD program. There he stayed, through his retirement in 1984, doing research right up to the end. Eight other schools received him as visiting professor. Lawrence knew that to make inroads into astronomy, he needed to apply physics to the observations, which he ardently sought. Little pleased him more than gathering photons, except perhaps for making atomic calculations with which he could analyze spectra. His real love was gaseous nebulae, specifically planetary nebulae (which he called his ``hobby"), the graceful shells of gas surrounding dying stars that are making their transitions to becoming white dwarfs. His range of simultaneous research projects was staggering. Having been an undergraduate student at Michigan in the late 1950s, I followed him to UCLA to work on my doctorate. When I arrived, I found him engaged in stellar spectroscopy, solar research, nebular theory, nebular observations (he tossed a box of plates at me and said in effect, ``here is your thesis"), and of all things Mie scattering theory to explain the zodiacal light! A list of his discoveries and influences is impressive. A sample: Lawrence played a major role in Menzel's group, which produced the famed ``Physical Processes in Gaseous Nebulae," an 18-part series that ran in the Astrophysical Journal from 1937 to 1945 and that explained nebular spectra. He was among the first to promulgate what in the 1940s was utter heresy, that the chemical compositions of stars could differ from one another. He was the first to observe gradients in spiral galaxies, which ultimately turned out to be the result of abundance variations. David Bohm and Lawrence established the existence of Maxwellian velocity distributions in nebular plasmas. Leo Goldberg, Edith Müller, and he were instrumental in establishing the chemical composition of the Sun. His observations of planetaries were legion. Never content with current observational and analytical capabilities, he sought out the latest equipment, from image tubes through CCDs to the best computers, ever looking ahead. His work was honored in 1992, when he received the American Astronomical Society's Russell Prize. Perhaps Lawrence's greatest legacy involved his teaching and writing. At Michigan, he taught a two-semester course in advanced general astronomy that covered nearly everything, in addition to a remarkable four-semester sequence in astrophysics (general, stellar atmospheres, nebular astrophysics, and stellar interiors). These were backed up by an extraordinary set of books. In 1943, Goldberg and he turned out the seminal toms, Stars, and Nebulae. (A solo third edition was published in 1991.) Then in 1953 arrived "The Atmospheres of the Sun and Stars" (revised a decade later), a tour de force on the physics of stellar plasmas and radiative transfer that became the bible of a generation of astronomers. "Nuclear Transformations, Stellar Interiors, and Nebulae" appeared a year later, and "Gaseous Nebulae" two years after that (rewritten in 1984 as "Physics of Thermal Gaseous Nebulae"). Not having a computer available in the early years, he used his students, creating mammoth "Aller Problems" that solved the equations for results that went into the books. Never formally published were two massive tomes of advanced general astronomy. To those of us lucky enough to have them, they serve as references to this day. His students, both undergraduate and graduate, are everywhere, their own students in turn carrying on Lawrence's ideas and work. In 1941, Lawrence married Rosalind Duncan Hall (who survives), and together they raised three children: Hugh, Gwen, and Raymond. Not only did one son become an astronomer, but so has one granddaughter (a dynasty established). Lawrence was absorbed by news and politics. He hated injustice of any kind, and let you know about it. He could entertain for hours with stories of his youth and of other astronomers, never realizing that he would also be the source of affectionate stories that would be told and retold by his own students. Of beautiful heart, he was a good father, both to his own children and to those he adopted as his students, none of whom, having been taught by him, will ever forget. Incredibly prolific, his vita lists over 500 publications, his first (in 1935) involving observations of the spectrum of Nova Herculis 1934, his last (in 2003!) the abundances of Hu1-2, fittingly one of his beloved planetary nebulae, one with a wonderfully deviant chemical composition.

  3. Assessing the application of an airborne intensified multispectral video camera to measure chlorophyll a in three Florida estuaries

    SciTech Connect

    Dierberg, F.E.; Zaitzeff, J.

    1997-08-01

    After absolute and spectral calibration, an airborne intensified, multispectral video camera was field tested for water quality assessments over three Florida estuaries (Tampa Bay, Indian River Lagoon, and the St. Lucie River Estuary). Univariate regression analysis of upwelling spectral energy vs. ground-truthed uncorrected chlorophyll a (Chl a) for each estuary yielded lower coefficients of determination (R{sup 2}) with increasing concentrations of Gelbstoff within an estuary. More predictive relationships were established by adding true color as a second independent variable in a bivariate linear regression model. These regressions successfully explained most of the variation in upwelling light energy (R{sup 2}=0.94, 0.82 and 0.74 for the Tampa Bay, Indian River Lagoon, and St. Lucie estuaries, respectively). Ratioed wavelength bands within the 625-710 nm range produced the highest correlations with ground-truthed uncorrected Chl a, and were similar to those reported as being the most predictive for Chl a in Tennessee reservoirs. However, the ratioed wavebands producing the best predictive algorithms for Chl a differed among the three estuaries due to the effects of varying concentrations of Gelbstoff on upwelling spectral signatures, which precluded combining the data into a common data set for analysis.

  4. MACROINVERTEBRATE PROTOCOLS ON ESTUARIES IN NEW JERSEY

    EPA Science Inventory

    Estuaries of the Atlantic coastal New Jersey extend from Newark Bay southward to Cape May Inlet. The rich diversities of habitats found in these estuaries provide important nursery areas for fish and marine invertebrates. Federal and state agencies routinely monitor estuaries fo...

  5. Ecology of estuaries: Anthropogenic effects

    SciTech Connect

    Kennish, M.J.

    1992-01-01

    Estuaries and near-shore oceanic water are subjected to a multitude of human wastes. The principal objective of this book is to examine anthropogenic effects on estuaries, and it focuses primarily on contaminants in coastal systems. Covered within various chapters are the following topics: waste disposal strategies; definition and classification of pollutants (including organic loading, oil pollution, polynuclear aromatic hydrocarbons; chlorinated hydrocarbons; heavy metals; radionuclides) biological impacts; waste management; impacts of power plants; dredging and spoil disposal; case studies, primarily Chesapeake Bay. The book serves as a text and as a reference.

  6. The Modification of an Estuary

    NASA Astrophysics Data System (ADS)

    Nichols, Frederic H.; Cloern, James E.; Luoma, Samuel N.; Peterson, David H.

    1986-02-01

    The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

  7. Technology transfer at Lawrence Berkeley Laboratory

    SciTech Connect

    Johnson, D.

    1992-09-01

    Lawrence Berkeley Laboratory (LBL) is dedicated to commercializing new technology in such fields as advanced materials, biotechnology, and electronics. Technology transfer between national laboratories and the industrial community is important in maintaining America`s competitive edge. This document examines opportunities to establish working relationships with LBL. Streamlined methods for technology transfer are available with the aid of the Technology Transfer Department and the Patent Department at LBL. Research activities at LBL are concentrated in three major program areas: Energy Sciences, General Sciences, and Biosciences. Each program area consists of three research divisions. LBL welcomes both requests for information and proposals to conduct research.

  8. Technology transfer at Lawrence Berkeley Laboratory

    SciTech Connect

    Johnson, D.

    1992-09-01

    Lawrence Berkeley Laboratory (LBL) is dedicated to commercializing new technology in such fields as advanced materials, biotechnology, and electronics. Technology transfer between national laboratories and the industrial community is important in maintaining America's competitive edge. This document examines opportunities to establish working relationships with LBL. Streamlined methods for technology transfer are available with the aid of the Technology Transfer Department and the Patent Department at LBL. Research activities at LBL are concentrated in three major program areas: Energy Sciences, General Sciences, and Biosciences. Each program area consists of three research divisions. LBL welcomes both requests for information and proposals to conduct research.

  9. Micro network unburdens Lawrence Livermore's supercomputers

    SciTech Connect

    Cecil, A.

    1983-03-01

    Many program-development installations that rely on time-sharing systems are distributing some of the programming tasks to microcomputer networks. The Lawrence Livermore National Laboratory, for example, has installed several microcomputer local networks as front-ends to its massive Octopus network, composed of Cray-1 and Control Data Corp. 7600 mainframes. One local network, which incorporated terminals from different vendors, is used by the programming group for nuclear weapons simulation. It allows programmers to perform local text editing, which reduces the time necessary to retrieve, modify and verify code, and frees the central host for compilation and execution. It also facilitates job resubmission and user scheduling.

  10. Lawrence Berkeley Laboratory 1994 site environmental report

    SciTech Connect

    1995-05-01

    The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

  11. The historical record of metal enrichment in two Florida estuaries

    SciTech Connect

    Alexander, C.R.; Smith, R.G. ); Calder, F.D.; Schropp, S.J. ); Windom H.L. )

    1993-12-01

    Historical profiles of metal accumulation have been generated for the lower St. Johns River and Hillsborough Bay, Florida, in cores representing approximately 50 yr of sediment and metal accumulation. These profiles demonstrate that Cd, Pb, and Zn are enriched in these Florida estuarine sediments. Pb enrichment has decreased since the mid 1970s because of reduced use of leaded gasoline. In the St. Johns River, most metals exhibit a trend of increasing enrichment with time. Cd enrichment significantly decreased between 1970 and 1975 as a result of reduced discharges into the river and control of aquatic vegetation. In Hillsborough Bay, enrichment factors for most metals are relatively high and show little change downcore. Cr, Cu, and Ni border on enrichment and Pb, Cd, and Zn are enriched. The results of this study are consistent with other studies of surficial-sediment metal concentration in other Florida estuaries. 39 refs., 5 figs., 2 tabs.

  12. DELAWARE ESTUARY A MANAGEMENT PLAN FOR THE DELAWARE ESTUARY

    EPA Science Inventory

    Wise conservation and management of the Delaware Estuary is arguably the most important cooperative environmental initiative ever jointly undertaken by the States of New Jersey, Pennsylvania, and Delaware. While much has been accomplished over the past few decades to improve wate...

  13. Pressure safety program Lawrence Livermore National Laboratory

    SciTech Connect

    Borzileri, C.; Traini, M.

    1992-10-01

    The Lawrence Livermore National Laboratory (LLNL) is a Research and Development facility. Programs include research in: nuclear weapons, energy, environmental, biomedical, and other DOE funded programs. LLNL is managed by the University of California for the Department of Energy. Many research and development programs require the use of pressurized fluid systems. In the early 1960`s, courses were developed to train personnel to safely work with pressurized systems. These courses served as a foundation for the Pressure Safety Program. The Pressure Safety Program is administered by the Pressure Safety Manager through the Hazards Control Department, and responsibilities include: (1) Pressure Safety course development and training, (2) Equipment documentation, tracking and inspections/retests, (3) Formal and informal review of pressure systems. The program uses accepted codes and standards and closely follows the DOE Pressure Safety Guidelines Manual. This manual was developed for DOE by Lawrence Livermore National Laboratory. The DOE Pressure Safety Guidelines Manual defines five (5) basic elements which constitute this Pressure Safety Program. These elements are: (1) A Pressure Safety Manual, (2) A Safety Committee, (3) Personnel who are trained and qualified, (4) Documentation and accountability for each pressure vessel or system, (5) Control of the selection and the use of high pressure hardware.

  14. Simulated Sampling of Estuary Plankton

    ERIC Educational Resources Information Center

    Fortner, Rosanne W.; Jenkins, Deborah Bainer

    2009-01-01

    To find out about the microscopic life in the valuable estuary environment, it is usually necessary to be near the water. This dry lab offers an alternative, using authentic data and a simulation of plankton sampling. From the types of organisms found in the sample, middle school students can infer relationships in the biological and physical…

  15. LAKE PONTCHARTRAIN ESTUARY CONSERVATION PLAN

    EPA Science Inventory

    The Nature Conservancy will conduct a series of a least four science expert workshops to develop a Site Conservation Plan for the Lake Pontchartrain Estuary and adjacent wetlands. The objective of the Site Conservation Plan is to identify conservation targets, threats or stresse...

  16. Food Webs in an Estuary.

    ERIC Educational Resources Information Center

    Dunne, Barbara B.

    The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on food chains in an estuary. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be…

  17. 6. Historic American Buildings Survey Lawrence Bradley Photographer April ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Historic American Buildings Survey Lawrence Bradley - Photographer April 6, 1936. FRONT ELEVATION OF TOWER - Independent Presbyterian Church, Bull & Oglethorpe Streets, Savannah, Chatham County, GA

  18. 8. Historic American Buildings Survey Lawrence Bradley Photographer April ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Historic American Buildings Survey Lawrence Bradley - Photographer April 6, 1936. INTERIOR DETAIL OF STAIRWAY - Independent Presbyterian Church, Bull & Oglethorpe Streets, Savannah, Chatham County, GA

  19. 10. Historic American Buildings Survey Lawrence Bradley Photographer April, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Historic American Buildings Survey Lawrence Bradley - Photographer April, 4, 1936 CEILING MAIN AUDITORIUM - Independent Presbyterian Church, Bull & Oglethorpe Streets, Savannah, Chatham County, GA

  20. Variation of baroclinicity over the spring-neap cycle in the Sumjin River estuary, Korea

    NASA Astrophysics Data System (ADS)

    Cho, Eun-Byeol; Cho, Yang-Ki; Seo, Gwang-Ho; Tak, Yong-Jin; Kim, Bong-Kuk

    2015-04-01

    Vertical velocity profiles and hydrography were intensively observed using Acoustic Doppler Current Profilers and CTD to understand the variation of baroclinicity over the spring-neap tidal cycle in the Sumjin River estuary, Korea. The Sumjin River estuary is a natural estuary in Korea. The river is 212km long, a drainage area is nearly 4,896km2 and the yearly mean discharge is 86.3m3/s. The Sumjin River estuary experiences a transition from partially- or well-mixed during spring tides (St < 0.15), but stratified conditions during neap tides (St > 0.32) based on the stratification parameter (St) which is the salinity difference between surface and bottom (δS) divided by the depth averaged salinity . The CTD observation cruises were taken at flood and ebb during neap tide and spring tide. The horizontal density gradient changes over fortnightly tidal cycle. The horizontal density gradient is small during neap tide. However it during spring tide dramatically increases about six to ten times larger than neap tide. The mean flow in the Sumjin River estuary displayed typical estuarine circulation which the surface layer flows seaward and the bottom layer flows landward. However, the snapshots of the velocity profiles showed dramatic changes with the tide. Velocity shear is strong during spring tides when the tidal range was at a maximum, while velocity shear is weak during neap tides when the tidal range was at a minimum. The change of tidal range induces baroclinic variations. An analytical model was applied to evaluate the effect of horizontal density on the velocity profile variation. The velocity profiles are determined by river discharge, horizontal density variations, and tide. Density variations act as a baroclinic pressure gradient, whereas the river discharge and tides act as a horizontal barotropic pressure gradient. The velocity profiles calculated by the analytical model suggest that the variation of baroclinicity over the spring-neap cycle is mainly caused by the horizontal density gradient.

  1. Lawrence Berkeley Laboratory Affirmative Action Program. Revised

    SciTech Connect

    1995-06-01

    The Lawrence Berkeley Laboratory`s Affirmative Action Program (AAP) serves as a working document that describes current policies, practices, and results in the area of affirmative action. It represents the Laboratory`s framework for an affirmative approach to increasing the representation of people of color and women in segments of our work force where they have been underrepresented and taking action to increase the employment of persons with disabilities and special disabled and Vietnam era veterans. The AAP describes the hierarchy of responsibility for Laboratory affirmative action, the mechanisms that exist for full Laboratory participation in the AAP, the policies and procedures governing recruitment at all levels, the Laboratory`s plan for monitoring, reporting, and evaluating affirmative action progress, and a description of special affirmative action programs and plans the Laboratory has used and will use in its efforts to increase the representation and retention of groups historically underrepresented in our work force.

  2. MAPPING BATHYMETRY AND BOTTOM TYPE IN A SHALLOW ESTUARY

    EPA Science Inventory

    Bathymetry and bottom type are important in characterizing estuaries and their ecology but hard to map, especially in shallow estuaries. Acoustic backscattering was used to remotely sense these properties in the shallow Slocums River Estuary of Massachusetts. Acoustic pulses were...

  3. Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

    EPA Science Inventory

    With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

  4. Astronauts Grunsfeld and Lawrence on middeck with ergometer

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Astronauts John M. Grunsfeld and Wendy B. Lawrence exercise on the middeck of the Earth-orbiting Space Shuttle Endeavour during the STS-67 mission. While Grunsfeld's pedaling is done on a real bicycle ergometer, Lawrence's movements are a convincing simulation without hardware.

  5. 4. Long view of west half of site from Lawrence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Long view of west half of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of rear portion of Wilder Mill and Paper Machine Building; view to southwest. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  6. 5. Long view of east half of site from Lawrence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Long view of east half of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of Clay Storage Silos and northeast block of Wilder Mill; view to southwest. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  7. 3. General view of site from Lawrence General Hospital parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view of site from Lawrence General Hospital parking deck (former location of coating mill) showing north side of structures; view to southeast. - Champion-International Paper Company, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  8. Jacob Lawrence's "The Great Migration." Integrating the Curriculum.

    ERIC Educational Resources Information Center

    Hodges, Alecia

    2001-01-01

    Presents an assignment where students write their own word-problems that incorporate parts of the book "The Great Migration: An American Story" by Jacob Lawrence and then illustrate their word-problems in the style of Lawrence. Explains that the book focuses on the Great Migration when African Americans moved to northern U.S. cities. (CMK)

  9. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... the Final Estuary Habitat Restoration Strategy (67 FR 71942). Section 106(f) of the Act authorizes the... National Oceanic and Atmospheric Administration RIN 0648-XX00 Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request for Public Comment...

  10. St. Lucia.

    PubMed

    1987-06-01

    The population of St Lucia was 123,000 in 1986, with an annual growth rate of 2%. The infant mortality rate stands at 22.2/1000 live births, and life expectancy is 70.3 years for males and 74.9 years for females. The literacy rate is 78%. St Lucia's labor force is allocated as follows: agriculture, 36.6%; industry and commerce, 20.1%; and services, 18.1%. The gross national product (GNP) was US$146 million in 1985, with an annual growth rate of 3% and a per capita GNP of $1071. St Lucia is a parliamentary democracy modeled on the British Westminster system. The island is divided into 16 parishes and 1 urban area (the capital, Castries). St Lucia is currently a politically stable country, although the high level of youth unemployment is a cause for concern. Ongoing stability may depend on the government's ability to provide services such as jobs and housing. The economy has evolved from a monocrop sugar plantation type to a diversified economy based on agriculture, industry, and tourism. Agriculture, dominated by the banana industry, is characterized by the participation of a large number of small and medium-sized enterprises. Industry is being encouraged through the provision of incentives such as tax rebates. The government is attempting to maintain a sound investment climate through a tripartite dialogue with the private sector and trade unions. Overall economic policy is predicated on the attraction of sound investments, by both local and foreign entities, to accelerate the rate of economic growth, solve the unemployment problem, and generate a solid balance-of-payments position. PMID:12177918

  11. Lawrence Livermore National Laboratory Environmental Report 2010

    SciTech Connect

    Jones, H E; Bertoldo, N A; Campbell, C G; Cerruti, S J; Coty, J D; Dibley, V R; Doman, J L; Grayson, A R; MacQueen, D H; Wegrecki, A M; Armstrong, D H; Brigdon, S L; Heidecker, K R; Hollister, R K; Khan, H N; Lee, G S; Nelson, J C; Paterson, L E; Salvo, V J; Schwartz, W W; Terusaki, S H; Wilson, K R; Woods, J M; Yimbo, P O; Gallegos, G M; Terrill, A A; Revelli, M A; Rosene, C A; Blake, R G; Woollett, J S; Kumamoto, G

    2011-09-14

    The purposes of the Lawrence Livermore National Laboratory Environmental Report 2010 are to record Lawrence Livermore National Laboratory's (LLNL's) compliance with environmental standards and requirements, describe LLNL's environmental protection and remediation programs, and present the results of environmental monitoring at the two LLNL sites - the Livermore site and Site 300. The report is prepared for the U.S. Department of Energy (DOE) by LLNL's Environmental Protection Department. Submittal of the report satisfies requirements under DOE Order 231.1A, Environmental Safety and Health Reporting, and DOE Order 5400.5, Radiation Protection of the Public and Environment. The report is distributed electronically and is available at https://saer.llnl.gov/, the website for the LLNL annual environmental report. Previous LLNL annual environmental reports beginning in 1994 are also on the website. Some references in the electronic report text are underlined, which indicates that they are clickable links. Clicking on one of these links will open the related document, data workbook, or website that it refers to. The report begins with an executive summary, which provides the purpose of the report and an overview of LLNL's compliance and monitoring results. The first three chapters provide background information: Chapter 1 is an overview of the location, meteorology, and hydrogeology of the two LLNL sites; Chapter 2 is a summary of LLNL's compliance with environmental regulations; and Chapter 3 is a description of LLNL's environmental programs with an emphasis on the Environmental Management System including pollution prevention. The majority of the report covers LLNL's environmental monitoring programs and monitoring data for 2010: effluent and ambient air (Chapter 4); waters, including wastewater, storm water runoff, surface water, rain, and groundwater (Chapter 5); and terrestrial, including soil, sediment, vegetation, foodstuff, ambient radiation, and special status wildlife and plants (Chapter 6). Complete monitoring data, which are summarized in the body of the report, are provided in Appendix A. The remaining three chapters discuss the radiological impact on the public from LLNL operations (Chapter 7), LLNL's groundwater remediation program (Chapter 8), and quality assurance for the environmental monitoring programs (Chapter 9). The report uses System International units, consistent with the federal Metric Conversion Act of 1975 and Executive Order 12770, Metric Usage in Federal Government Programs (1991). For ease of comparison to environmental reports issued prior to 1991, dose values and many radiological measurements are given in both metric and U.S. customary units. A conversion table is provided in the glossary.

  12. A theoretical framework for analyzing the effect of external change on tidal dynamics in estuaries

    NASA Astrophysics Data System (ADS)

    CAI, H.; Savenije, H.; Toffolon, M.

    2013-12-01

    The most densely populated areas of the world are usually located in coastal areas near estuaries. As a result, estuaries are often subject to intense human interventions, such as dredging for navigation, dam construction and fresh water withdrawal etc., which in some areas has led to serious deterioration of invaluable ecosystems. Hence it is important to understand the influence of such interventions on tidal dynamics in these areas. In this study, we present one consistent theoretical framework for tidal hydrodynamics, which can be used as a rapid assessment technique that assist policy maker and managers to make considered decisions for the protection and management of estuarine environment when assessing the effect of human interventions in estuaries. Analytical solutions to the one-dimensional St. Venant equations for the tidal hydrodynamics in convergent unbounded estuaries with negligible river discharge can be cast in the form of a set of four implicit dimensionless equations for phase lag, velocity amplitude, damping, and wave celerity, as a function of two localized parameters describing friction and convergence. This method allows for the comparison of the different analytical approaches by rewriting the different solutions in the same format. In this study, classical and more recent formulations are compared, showing the differences and similarities associated to their specific simplifications. The envelope method, which is based on the consideration of the dynamics at high water and low water, can be used to derive damping equations that use different friction approximations. This results in as many analytical solutions, and thereby allows one to build a consistent theoretical framework. Analysis of the asymptotic behaviour of the equations shows that an equilibrium tidal amplitude exits reflecting the balance between friction and channel convergence. The framework is subsequently extended to take into account the effect of river discharge. Hence, the analytical solutions are applicable even in the upstream part of an estuary, where the influence of river discharge is remarkable. The proposed analytical solutions are transparent and practical, allowing a quantitative and qualitative assessment of human interventions (e.g., dredging, flow reduction) on tidal dynamics. Moreover, they are rapid assessment techniques that enable the users to set up a simple model and to understand the functioning of the system with a minimum of information required. The analytical model is illustrated in three large-scale estuaries with significant influence by human activities, i.e., the Scheldt estuary in the Netherlands, the Modaomen and the Yangtze estuaries in China. In these estuaries, the correspondence with observations is good, which suggests that the proposed model is a useful, yet realistic and reliable instrument for quick detection of the effect of human interventions on tidal dynamics and subsequent environmental issues, such as salt intrusion.

  13. Dissolved Oxygen Data for Coos Estuary (Oregon)

    EPA Science Inventory

    The purpose of this product is the transmittal of dissolved oxygen data collected in the Coos Estuary, Oregon to Ms. Molly O'Neill (University of Oregon), for use in her studies on the factors influencing spatial and temporal patterns in dissolved oxygen in this estuary. These d...

  14. A Climate Ready Estuaries Vulnerability Assessment

    EPA Science Inventory

    The purpose of the the Climate Ready Estuaries program is to build capacity in the National Estuary Programs (NEPs) for local leadership and expertise to adapt to the effects of climate change through a joint effort with the NEPs and EPA.

    Background
    The Climate Ready...

  15. NEW HAMPSHIRE ESTUARIES PROJECT MANAGEMENT PLAN

    EPA Science Inventory

    This Comprehensive Conservation and Management Plan of the New Hampshire Estuaries Project presents a broad framework and specific list of actions to protect and enhance the environmental quality of the estuaries of the State of New Hampshire. It is intended to be a guide for all...

  16. AFS Estuaries Section - A Successful Partnership

    EPA Science Inventory

    The Estuaries Section of the American Fisheries Society offers travel awards to students in support of their attendance and presentations at the AFS meeting. Since 2007, the Southern Association of Marine Laboratories has partnered with the Estuaries Section to sponsor two stude...

  17. NEW HAMPSHIRE ESTUARIES PROJECT MANAGEMENT PLAN, 2000

    EPA Science Inventory

    The Comprehensive Conservation and Management Plan of the New Hampshire Estuaries Project presents a broad framework and specific list of actions to protect and enhance the environmental quality of the estuaries of the State of New Hampshire. It is intended to be a guide for all ...

  18. 9. Historic American Buildings Survey Lawrence Bradley Photographer April ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Historic American Buildings Survey Lawrence Bradley - Photographer April 6, 1936. INTERIOR VIEW OF COLUMNS AND DOME MAIN AUDITORIUM - Independent Presbyterian Church, Bull & Oglethorpe Streets, Savannah, Chatham County, GA

  19. Former Fermilab boss to lead Lawrence Berkeley National Laboratory

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2016-03-01

    Particle physicist Michael Witherell - current vice-chancellor for research at the University of California, Santa Barbara (UCSB) - has been appointed the next director of the Lawrence Berkeley National Laboratory (LBL).

  20. 5. Historic American Buildings Survey Lawrence Bradley Photographer April, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Historic American Buildings Survey Lawrence Bradley - Photographer April, 16, 1936 RUINS VIEW OF RECTANGULAR TERMINATING SECTION - Santo Domingo Mission (Ruins), Near Altamaha Canal (River), Broadfield, Glynn County, GA

  1. Technology transfer activities at the Lawrence Berkeley Laboratory

    SciTech Connect

    Lemmon, R.M.

    1981-10-01

    Research activities at the Lawrence Berkeley Laboratory are described concerning x-ray fluorescence analysis; magnetotellurics in geological exploration; solid-state ballasts for fluorescent lamps; medical imaging; and neutral beam sources.

  2. Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1980

    SciTech Connect

    Schleimer, G.E.

    1981-04-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data on air and water sampling and continuous radiation monitoring for 1980 are presented, and general trends are discussed.

  3. Astronauts Lawrence and Gregory debrief each other before new shift

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Astronauts Wendy B. Lawrence and William G. Gregory debrief each other on the flight deck of the Earth orbiting Space Shuttle Endeavour during the STS-67 mission. Lawrence, mission specialist and flight engineer, served as the pilot on the blue shift and Gregory filled that position for the red shift. The two, along with Stephen S. Oswald, mission commander, provided round-the-clock support to the ASTRO-2 payload's timelines, performing maneuvers to put Endeavour in the proper attitudes for onboard experiments.

  4. Annual environmental monitoring report of the Lawrence Berkeley Laboratory

    SciTech Connect

    Schleimer, G.E.; Pauer, R.O.

    1990-08-01

    The Lawrence Berkeley Laboratory (LBL) is a multiprogram national laboratory managed by the University of California (UC) for the US Department of Energy (DOE). LBL's major role is to conduct basic and applied science research that is appropriate for an energy research laboratory. The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1989 are presented, and general trends are discussed. 17 refs., 12 figs., 23 tabs.

  5. STS-67 Flight Engineer Wendy Lawrence Suites Up

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In the Operations and Checkout Building, STS-67 Mission Specialist and Flight Engineer Wendy B. Lawrence is donning her launch/entry suit with assistance from a suit technician. Lawrence -- who is about to make her first trip into space -- and six fellow crew members will soon depart for Launch Pad 39A, where the Space Shuttle Endeavour is being readied for liftoff during a launch window opening at 1:37 a.m. EST, March 2.

  6. Lawrence hydroelectric project: resurrection of a low-head dam

    SciTech Connect

    Not Available

    1982-04-01

    The Lawrence Hydroelectric Project, located on the Merrimac River in Lawrence, Mass, is one of the first hydro projects completed since the oil crisis and has set an important precedent for the development of other low-head generation systems in New England. The hydroelectric project is built alongside the old 920-ft-long granite dam. The plant uses two bulb-type Kaplan turbine/generator units, each rated at 8.4 MW.

  7. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection - May 16, 2011

    EPA Science Inventory

    We examined the role of the ocean estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  8. Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection - May 16, 2011

    EPA Science Inventory

    We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

  9. Health of white sucker within the St. Louis River area of concern associated with habitat usage as assessed using stable isotopes

    EPA Science Inventory

    In Spring 2011, 200 adult white sucker were collected in four areas of the St. Louis River Area of Concern (AOC), located in Minnesota and Wisconsin, USA. The areas included the upper AOC as a reference area, the upper estuary, St. Louis Bay and Superior Bay. Grossly visible abno...

  10. Water Column Methylation in Estuaries

    NASA Astrophysics Data System (ADS)

    Schartup, A. T.; Calder, R.; Soerensen, A. L.; Mason, R. P.; Balcom, P. H.; Sunderland, E. M.

    2014-12-01

    Methylmercury (MeHg) is a neurotoxin that bioaccumulates in aquatic food webs and affects humans and wildlife through fish consumption. Many studies have measured active methylation/demethylation in ocean margin sediments but few have reported similar rates for the marine water column. This presentation will review available evidence for water column methylation in estuaries, including new experimental measurements of methylation/demethylation rates from a deep subarctic fjord in Labrador Canada collected in Spring and Fall of 2012-2013. We used these and other data to construct a mass budget for MeHg in the estuary and show that water column methylation (with rates ranging from 1.5 to 2.8 % day-1), is the largest contributor, followed by inputs from rivers (4.9 mol year-1), to the in situ pool of MeHg available for uptake by biota. By contrast, the sediment in this system is a net sink for MeHg (-1.5 mol year-1). We discuss the relationship between observed MeHg and other ancillary environmental factors (organic carbon, sulfur and nutrients) as well as implications for the response time of fish to future changes in mercury inputs.

  11. Numerical modelling of morphodynamics—Vilaine Estuary

    NASA Astrophysics Data System (ADS)

    Vested, Hans Jacob; Tessier, Caroline; Christensen, Bo Brahtz; Goubert, Evelyne

    2013-04-01

    The main objective of this paper is to develop a method to simulate long-term morphodynamics of estuaries dominated by fine sediments, which are subject to both tidal flow and meteorologically induced variations in freshwater run-off and wave conditions. The method is tested on the Vilaine Estuary located in South Brittany, France. The estuary is subject to a meso-macrotidal regime. The semi-diurnal tidal range varies from around 2.5 to 5 m at neap and spring, respectively. The freshwater input is controlled by a dam located approximately 8 km from the mouth of the estuary. Sediments are characterised as mostly fines, but more sandy areas are also found. The morphology of the estuary is highly influenced by the dam. It is very dynamic and changes in a complicated manner with the run-off from the dam, the tide and the wave forcing at the mouth of the estuary. Extensive hydrodynamic and sediment field data have been collected in the past and provide a solid scientific basis for studying the estuary. Based on a conceptual understanding of the morphodynamics, a numerical morphological model with coupled hydrodynamic, surface wave and sediment transport models is formulated. The numerical models are calibrated to reproduce sediment concentrations, tidal flat altimetry and overall sediment fluxes. Scaling factors are applied to a reference year to form quasi-realistic hydrodynamic forcing and river run-off, which allow for the simulations to be extended to other years. The simulation results are compared with observed bathymetric changes in the estuary during the period 1998-2005. The models and scaling factors are applied to predict the morphological development over a time scale of up to 10 years. The influence of the initial conditions and the sequence of external hydrodynamic forcing, with respect to the morphodynamic response of the estuary, are discussed.

  12. Obituary: Fred Lawrence Whipple, 1906-2004

    NASA Astrophysics Data System (ADS)

    Yeomans, Donald Keith

    2004-12-01

    Fred Whipple, one of the founding fathers of planetary science, died on August 30, 2004 just two months shy of his 98th birthday. The breadth of Fred's published research from 1927 through 2000 is quite extraordinary. Although his collected works were published in two massive volumes in 1972, shortly before his retirement, Fred's research contributions continued for another three decades - and another volume is planned. Fred Lawrence Whipple was born on November 5, 1906 on a farm in Red Oak Iowa. His parents were Harry Lawrence and Celestia (MacFarl) Whipple. At the age of fifteen, the Whipple family moved to California where Fred studied mathematics at Occidental College and the University of California at Los Angeles. As a graduate student at the University of California at Berkeley in 1930, he was one of the first to compute an orbit for the newly discovered planet Pluto. Upon receiving his PhD in 1931, he joined the staff of the Harvard College Observatory. He was Chairman of the Harvard Department of Astronomy (1949 - 1956), Director or the Smithsonian Astrophysical Observatory (1955 - 1973), Phillips Professor of Astronomy (1968 - 1977) and Emeritus Phillips Professor of astronomy (1977 - 2004). In 1928 he married Dorothy Woods and their son, Earle Raymond, survives him. The marriage ended in divorce in 1935. Eleven years later, he married Babette F. Samelson and she too survives him, as do their two daughters Laura and (Dorothy) Sandra. Shortly after arriving at Harvard in the early 1930's, Fred developed a photographic tracking network to determine meteor trajectories from simultaneous observations from two or more stations. The photographic trails, chopped by a rotating shutter, allowed their orbits in space to be determined accurately. With the strong involvement of Richard McCrosky and others, he concluded in the early 1960's that most of these meteors were on comet-like orbits and less than 1% of the naked eye, sporadic meteors could be traced to an origin outside the solar system. To fill the daytime gap when meteors could not be photographed, Fred organized a program for the radio detection of these objects. With the launch of Sputnik in October 1957, Whipple's visual network of amateur astronomers (Moon watch) was already in place to follow its progress and later on he developed an optical tracking system for meteors and artificial satellites using wide field, Baker-Nunn cameras. This latter system proved so successful that the precision tracking of these satellites could be used to model the Earth's shape and density variations from the observed gravitational effects upon these satellite orbits. He once noted that the highlight of his career was having his family and parents present at the White House while he received the President's Award for Distinguished Public Service from John F. Kennedy for this work. His seminal works in 1950-51 on the icy conglomerate model for the cometary nucleus prompted a complete paradigm switch. Until then, the current consensus model for a comet was a flying cloud of particles; it had been so since the second half of the nineteenth century when comets were identified with meteor showers. He envisaged the cometary nucleus as a conglomerate of ices (mostly water, ammonia, methane, carbon dioxide and carbon monoxide ices) embedded within, and covered over with, a nonvolatile matrix of meteoric material. Part of his rationale for developing this "dirty snowball" model for the cometary nucleus was to provide an explanation of the so-called nongravitational forces acting upon comets. The rocket-like thrusting of a comet when the ices vaporize near the sun introduced a small, but noticeable, thrust on the comet itself and when this effect was properly modeled, the motions of active comets could be predicted far more accurately. Subsequent spacecraft ultraviolet observations showing enormous cometary hydrogen atmospheres confirmed that the major cometary ice was likely to be water. The 1986 Giotto spacecraft images, revealing a solid cometary nucleus (albeit far blacker than most had predicted), were a dramatic confirmation of Whipple's model -- though in truth few really expected otherwise at the time. In 1942-1946, he led an effort to develop and implement strips of reflective aluminum (i.e., chaff) to confuse enemy radars in World War II. In 1948, he received a certificate of merit for this work from President Harry S. Truman. Eleven years before the launch of the first artificial satellite in 1957, he developed what is now generally termed the Whipple Shield; a thin outer metallic layer stands out from a spacecraft and protects it from high-speed interplanetary dust particles. While particles hitting this outside thin layer would penetrate, they would also vaporize, and in so doing, the resultant debris would disperse and lack the energy to penetrate the main spacecraft skin. This design was used to successfully protect the Stardust spacecraft from cometary dust particles when the spacecraft flew rapidly past comet Tempel 1 in January 2004. He also made significant contributions to fields as diverse as meteor astronomy, satellite tracking, variable stars, supernovae, stellar evolution, astronomical instrumentation and radio astronomy. Along with his colleagues Willy Ley, Wernher von Braun and others, Fred wrote and consulted for a series of very popular articles in Collier's magazine in the early 1950's and these articles, along with earlier lectures at New York's Hayden Planetarium, helped spark the U.S. involvement in space exploration. Of these early beginnings of space exploration, Fred wrote in 1972 "it was no easy task to convince people that man could really go into empty space beyond the Earth's atmosphere, and even beyond the Earth's tenacious gravitational grasp. On looking back over these years, I am still surprised that we succeeded in convincing them." Fred was responsible for initiating the Smithsonian Astrophysical Observatory's observatory on Mt. Hopkins near Tucson Arizona and he was active in the design of the multi-mirror telescope that was in operation until 1999, when a 6.5-meter single mirror telescope replaced it. In 1981, the observatory was renamed the Fred Lawrence Whipple Observatory. Fred was successful as both a manager of large science enterprises and as a researcher. He once told me that one of his secrets for doing both management and science simultaneously involved his spending some mornings in a room adjacent to his office doing research. His secretary was asked to (correctly) notify morning callers that Dr. Whipple was not in his office at the moment and could he return the call later on in the day. When asked the secret of his longevity at his 90th birthday party, he noted, "you've got to start early." Fortunately for Planetary Science, he did start early - and he stayed late. Until he reached 90 years of age, he rode his bicycle to the office most every day and those days when he drove to work, his car was easy to identify from the single word "comets" on his license plate. Fred Whipple was awarded seven honorary degrees and included among his many tributes are a certificate of Merit from President Truman (1948), the J. Lawrence Smith Medal of the National Academy of Sciences (1949), a Distinguished Federal Civilian Service Award (1963), the Frederick C. Leonard Memorial Medal of the Meteoritical Society (1970), the Gold Medal of the Royal Society (1983), the Bruce Medal of the Astronomical Society of the Pacific (1986), and the Henry Norris Russell Lectureship of the American Astronomical Society (1987). He also discovered six new comets and discovered and named an asteroid (1252 Celestia) after his mother. Asteroid 1940 was renamed (1940) Whipple to honor his professional achievements. Fred Whipple was a Harvard Professor, director of the Smithsonian Astrophysical Observatory, a Presidential medallist and his name is synonymous with comets. He was one of the few great innovative thinkers in twentieth century planetary science. Yet through it all, he remained just Fred to all who knew him. Whether you were a young student or a distinguished internationally recognized scientist, this gentleman treated everyone with the same kindness and respect. The entire planetary science community has benefited immeasurably from his wide-ranging insights; we've lost a creative scientist and a kind mentor - but he remains a superb role model for us all. This obituary is based on one by D.K. Yeomans and J. Veverka that appeared in "Nature" (4 Nov. 2004, vol. 432, p. 31). Photograph provided by J. Veverka.

  13. Efficacy of iodine for disinfection of Lake Sturgeon eggs from the St. Lawrence River, New York

    USGS Publications Warehouse

    Chalupnicki, Marc; Dittman, Dawn E.; Starliper, Clifford E.; Iwanowicz, Deborah

    2014-01-01

    Optimal fish husbandry to reduce the risk of disease is particularly important when using wild fish as the source for gametes. The propagation and reestablishment of Lake Sturgeon Acipenser fulvescens in New York waters to become a viable self-sustaining population is considered a high priority by managers. While standard hatchery egg disinfection practices have been used to prevent the transmission of diseases, data on the bacterial loads present on egg surfaces following iodine disinfection is lacking. Our study investigated the bacteria present on the outer surface of Lake Sturgeon eggs and the effectiveness of an iodine disinfection treatment in eliminating bacteria that could pose a threat to egg survival and cause hatchery disease outbreaks. During the springs of 2011–2013, 12 to 41 different species of bacteria were recovered from the outer egg surfaces prior to an iodine treatment; Aeromonas, Pseudomonas, Shewanella, and Chryseobacterium were the most common genera identified. Cohort eggs treated using the standard protocol of a single treatment of 50 mg/L iodine for 30 min resulted in an average of 57.8% reduction in bacterial CFU/g. While this is a significant reduction, bacteria were not completely eliminated and hatchery managers should be aware that pathogens could remain on Lake Sturgeon eggs following the standard iodine disinfection treatment.

  14. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    SciTech Connect

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  15. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska.

    PubMed

    Hamilton, Terry; Seagars, Dana; Jokela, Terry; Layton, David

    2008-06-01

    The activity concentration of Cesium-137 ((137)Cs) and naturally-occurring Polonium-210 ((210)Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean (137)Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg(-1) (n=2, wet weight), respectively, in bearded seal. In general, (137)Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, (210)Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean (210)Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n=5, wet weight) were 28.7, 189, and 174 Bq kg(-1), respectively. This compares with (210)Po concentration values (n=2, wet weight) of 27, 207 and 68 Bq kg(-1) measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for (210)Po that those of (137)Cs. We conclude from radiological dose estimates that ingestion of (137)Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic. PMID:18371988

  16. Marine Mammal Strandings and Environmental Changes: A 15-Year Study in the St. Lawrence Ecosystem

    PubMed Central

    Truchon, Marie-Hélène; Measures, Lena; L’Hérault, Vincent; Brêthes, Jean-Claude; Galbraith, Peter S.; Harvey, Michel; Lessard, Sylvie; Starr, Michel; Lecomte, Nicolas

    2013-01-01

    Understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. We used general linear models to analyze a 15-year database documenting marine mammal strandings (1994–2008; n = 1,193) and nine environmental parameters known to affect marine mammal survival, from regional (sea ice) to continental scales (North Atlantic Oscillation, NAO). Stranding events were more frequent during summer and fall than other seasons, and have increased since 1994. Poor ice conditions observed during the same period may have affected marine mammals either directly, by modulating the availability of habitat for feeding and breeding activities, or indirectly, through changes in water conditions and marine productivity (krill abundance). For most species (75%, n = 6 species), a low volume of ice was correlated with increasing frequency of stranding events (e.g. R2adj = 0.59, hooded seal, Cystophora cristata). This likely led to an increase in seal mortality during the breeding period, but also to increase habitat availability for seasonal migratory cetaceans using ice-free areas during winter. We also detected a high frequency of stranding events for mysticete species (minke whale, Balaenoptera acutorostrata) and resident species (beluga, Delphinapterus leucas), correlated with low krill abundance since 1994. Positive NAO indices were positively correlated with high frequencies of stranding events for resident and seasonal migratory cetaceans, as well as rare species (R2adj = 0.53, 0.81 and 0.34, respectively). This contrasts with seal mass stranding numbers, which were negatively correlated with a positive NAO index. In addition, an unusual multiple species mortality event (n = 114, 62% of total annual mortality) in 2008 was caused by a harmful algal bloom. Our findings provide an empirical baseline in understanding marine mammal survival when faced with climatic variability. This is a promising step in integrating stranding records to monitor the consequences of environmental changes in marine ecosystems over long time scales. PMID:23544059

  17. Citizens' Guide to Biomonitoring in the Great Lakes and St. Lawrence River.

    ERIC Educational Resources Information Center

    Great Lakes United, Buffalo, NY.

    The purpose of this report is to present the issues surrounding biomonitoring of wastewaters discharged into the Great Lakes Basin. Biomonitoring is the process of using organisms to monitor the toxicity of a substance. The report reflects an interest in seeing zero discharge of toxic pollutants in the Great Lakes region. The report is organized…

  18. Ground-water availability from the unconsolidated deposits of the St. Lawrence River Basin, New York

    USGS Publications Warehouse

    Bugliosi, Edward F.

    1987-01-01

    Protection of New York State 's aquifers has become an increasingly important issue among water resource managers at all levels of State and Local government. Aquifer delineation is necessary as an initial phase in the effective management of the State 's groundwater resources. Many of New York 's productive aquifers consist of unconsolidated deposits. In an effort to obtain complete coverage of all the significant unconsolidated aquifers in New York, the U.S. Geological Survey and the New York State Department of Environmental Conservation began a cooperative study in 1985 to compile groundwater availability maps of each major river basin. This map delineates the unconsolidated aquifers that underlie the State 's northernmost eight counties and gives the estimated potential yield of properly constructed wells completed in these aquifers. Additional well locations and delineation of the aquifers were obtained through a well inventory conducted during the study. (Lantz-PTT)

  19. DISTRIBUTION AND TRANSFORMATION OF ELEMENTAL MERCURY IN THE ST. LAWRENCE RIVER AND LAKE ONTARIO. (R827915)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Potsdam/St. Lawrence County Recycling Demonstration project. Researching wastepaper use for animal bedding. Final report

    SciTech Connect

    Weber, L.J.; McQuinn, L.

    1997-04-01

    This report describes the demonstration of a municipal recycling program and the results of the use of collected mixed paper as animal bedding. The project included demonstration of several collection methods applicable for rural communities, including a curbside collection program in the Village of Potsdam and drop-off collection in some surrounding areas. The collected materials were upgraded at a private materials-processing facility. Some mixed paper was shredded to produce three types of wastepaper animal bedding. The project also examined biodegradation of used bedding and manure and the mobility of metals found in paper of manure. In the laboratory test program, mixture of manure and wastepaper beddings decomposed more slowly than hay bedding mixtures. However in field tests at the cooperator farm, wastepaper beddings degraded quickly enough to effectively disappear soon after landspreading.

  1. Structure and Dynamics of Minke Whale Surfacing Patterns in the Gulf of St. Lawrence, Canada

    PubMed Central

    Christiansen, Fredrik; Lusseau, David; Tscherter, Ursula

    2015-01-01

    Animal behavioral patterns can help us understand physiological and ecological constraints on animals and its influence on fitness. The surfacing patterns of aquatic air-breathing mammals constitute a behavioral pattern that has evolved as a trade-off between the need to replenish oxygen stores at the surface and the need to conduct other activities underwater. This study aims to better understand the surfacing pattern of a marine top predator, the minke whale (Balaenoptera acutorostrata), by investigating how their dive duration and surfacing pattern changes across their activity range. Activities were classified into resting, traveling, surface feeding and foraging at depth. For each activity, we classified dives into short and long dives and then estimated the temporal dependence between dive types. We found that minke whales modified their surfacing pattern in an activity-specific manner, both by changing the expression of their dives (i.e. density distribution) and the temporal dependence (transition probability) between dive types. As the depth of the prey layer increased between activities, the surfacing pattern of foraging whales became increasingly structured, going from a pattern dominated by long dives, when feeding at the surface, to a pattern where isolated long dives were followed by an increasing number of breaths (i.e. short dives), when the whale was foraging at depth. A similar shift in surfacing pattern occurred when prey handling time (inferred from surface corralling maneuvers) increased for surface feeding whales. The surfacing pattern also differed between feeding and non-feeding whales. Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport. Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles. PMID:25970425

  2. Marine mammal strandings and environmental changes: a 15-year study in the St. Lawrence ecosystem.

    PubMed

    Truchon, Marie-Hélène; Measures, Lena; L'Hérault, Vincent; Brêthes, Jean-Claude; Galbraith, Peter S; Harvey, Michel; Lessard, Sylvie; Starr, Michel; Lecomte, Nicolas

    2013-01-01

    Understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. We used general linear models to analyze a 15-year database documenting marine mammal strandings (1994-2008; n = 1,193) and nine environmental parameters known to affect marine mammal survival, from regional (sea ice) to continental scales (North Atlantic Oscillation, NAO). Stranding events were more frequent during summer and fall than other seasons, and have increased since 1994. Poor ice conditions observed during the same period may have affected marine mammals either directly, by modulating the availability of habitat for feeding and breeding activities, or indirectly, through changes in water conditions and marine productivity (krill abundance). For most species (75%, n = 6 species), a low volume of ice was correlated with increasing frequency of stranding events (e.g. R(2)adj = 0.59, hooded seal, Cystophora cristata). This likely led to an increase in seal mortality during the breeding period, but also to increase habitat availability for seasonal migratory cetaceans using ice-free areas during winter. We also detected a high frequency of stranding events for mysticete species (minke whale, Balaenoptera acutorostrata) and resident species (beluga, Delphinapterus leucas), correlated with low krill abundance since 1994. Positive NAO indices were positively correlated with high frequencies of stranding events for resident and seasonal migratory cetaceans, as well as rare species (R(2)adj = 0.53, 0.81 and 0.34, respectively). This contrasts with seal mass stranding numbers, which were negatively correlated with a positive NAO index. In addition, an unusual multiple species mortality event (n = 114, 62% of total annual mortality) in 2008 was caused by a harmful algal bloom. Our findings provide an empirical baseline in understanding marine mammal survival when faced with climatic variability. This is a promising step in integrating stranding records to monitor the consequences of environmental changes in marine ecosystems over long time scales. PMID:23544059

  3. Structure and dynamics of minke whale surfacing patterns in the Gulf of St. Lawrence, Canada.

    PubMed

    Christiansen, Fredrik; Lynas, Ned M; Lusseau, David; Tscherter, Ursula

    2015-01-01

    Animal behavioral patterns can help us understand physiological and ecological constraints on animals and its influence on fitness. The surfacing patterns of aquatic air-breathing mammals constitute a behavioral pattern that has evolved as a trade-off between the need to replenish oxygen stores at the surface and the need to conduct other activities underwater. This study aims to better understand the surfacing pattern of a marine top predator, the minke whale (Balaenoptera acutorostrata), by investigating how their dive duration and surfacing pattern changes across their activity range. Activities were classified into resting, traveling, surface feeding and foraging at depth. For each activity, we classified dives into short and long dives and then estimated the temporal dependence between dive types. We found that minke whales modified their surfacing pattern in an activity-specific manner, both by changing the expression of their dives (i.e. density distribution) and the temporal dependence (transition probability) between dive types. As the depth of the prey layer increased between activities, the surfacing pattern of foraging whales became increasingly structured, going from a pattern dominated by long dives, when feeding at the surface, to a pattern where isolated long dives were followed by an increasing number of breaths (i.e. short dives), when the whale was foraging at depth. A similar shift in surfacing pattern occurred when prey handling time (inferred from surface corralling maneuvers) increased for surface feeding whales. The surfacing pattern also differed between feeding and non-feeding whales. Resting whales did not structure their surfacing pattern, while traveling whales did, possibly as a way to minimize cost of transport. Our results also suggest that minke whales might balance their oxygen level over multiple, rather than single, dive cycles. PMID:25970425

  4. Water resources data, Ohio: Water year 1991. Volume 2, St. Lawrence River Basin: Statewide project data

    SciTech Connect

    Shindel, H.L.; Klingler, J.H.; Mangus, J.P.; Trimble, L.E.

    1992-03-01

    The Water Resources Division of the US Geological Survey (USGS), in cooperation with State agencies, obtains a large amount of data pertaining to the water resources of Ohio each water year. These data, accumulated during many years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the USGS, the data are published annually in this report series entitled ``Water Resources Data--Ohio.`` This report (in two volumes) includes records on surface water and ground water in the State. Specifically, it contains: (1) Discharge records for 131 streamflow-gaging stations, 95 miscellaneous sites; (2) stage and content records for 5 streams, lakes, and reservoirs; (3) water-quality for 40 streamflow-gaging stations, 378 wells, and 74 partial-record sites; and (4) water levels for 431 observation wells.

  5. Assessing the susceptibility of two UK estuaries to nutrient enrichment

    NASA Astrophysics Data System (ADS)

    Kadiri, Margaret; Bockelmann-Evans, Bettina; Rauen, William B.

    2014-10-01

    The susceptibility of two UK estuaries, the Severn and Solva Estuaries to the risks and impacts of nutrient enrichment was investigated in this study by examining nutrients, dissolved oxygen (DO) and turbidity concentrations in the estuaries and applying a risk assessment model based on the UK's Comprehensive Studies Task Team (CSTT) modelling approach. Both estuaries were found to be nutrient enriched. However, there was no evidence of oxygen depletion in the Severn and algal blooms were not observed due to high turbidity, strong tidal currents and tidally induced vertical mixing conditions in the estuary. Although algal blooms were observed in the Solva Estuary, the estuary was well-oxygenated due to the relatively high water exchange rate and consistent rapid flushing in the estuary. The conditions in the Solva Estuary were predicted to be favourable for phytoplankton productivity and the wider potential implications for future water quality protection strategies in the Solva were discussed.

  6. Estimating bankfull discharge and depth in ungauged estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, Jacqueline Isabella Anak; Savenije, Hubert H. G.

    2015-04-01

    It is difficult to measure river discharge accurately in an estuary, and particularly, in the region where the tidal flow dominates over the river discharge. River discharge is important for the morphology and hydrodynamics of estuaries as it influences the salt intrusion process, tidal dynamics, freshwater supply (water resources management), and the occurrence of floods. Here we try to derive river regime characteristics from the seaward end: the estuary. It is found that there are empirical relationships that link the geometry of an estuary to its river regime, which can be used to estimate river discharge characteristics with the least of data available. The aims of this study are: (1) to derive empirical relations between geometrical characteristics of estuaries and the bankfull discharge; (2) to explore a physical explanation for this relation; and (3) to estimate the bankfull discharge in estuaries. The physical connection between an estuary and its river regime is found by combining estuary shape analysis, tidal dynamic analysis, and Lacey's hydraulic geometry theory. The relationships found between the estuary depth, width, and bankfull river discharge have been tested in 23 estuaries around the world (including seven recently surveyed estuaries). From the analysis, it shows that the depth of an estuary is a function of the bankfull flood discharge to the power of 1/3, which is in agreement with Lacey's formula. This finding not only provides a method to estimate estuary depth, it also allows estimating flood discharge characteristics from readily available estuary shape indicators.

  7. EPA'S BENTHIC HABITAT DATA FOR YAQUINA ESTUARY

    EPA Science Inventory

    Scientists at EPA's National Health and Environmental Effects Research Laboratory, Western Ecology Division (WED) have been studying seafloor (benthic) habitats in Yaquina estuary for several years. Those studies were conducted as parts of several research projects, including: e...

  8. ECOLOGICAL CONDITION OF SOUTH FLORIDA ESTUARIES

    EPA Science Inventory

    An assessment of the ecological condition of south Florida estuaries based on regional probabilistic monitoring was conducted during the summer of 1995. Samples and data were collected on water and sediment quality, benthos, and fish tissue contaminants. Elevated concentrations o...

  9. The Peel Inlet-Harvey Estuary Study.

    ERIC Educational Resources Information Center

    Walker, Warren; Black, Ronald

    1979-01-01

    Describes how the department of physics of the Western Australian Institute of Technology (WAIT) has been involved in the Peel Inlet-Harvey Estuary study. An appendix which presents the departmental approach to curriculum matters is also included. (HM)

  10. PECONIC ESTUARY PROGRAM TIDAL CREEK STUDY

    EPA Science Inventory

    EEA evaluated ten tidal creeks throughout the Peconic Estuary representing a wide range of watershed variables. Primary focus was directed towards the collection and analysis of the macrobenthic invertebrate communities of these ten tidal creeks. Analysis of the macrobenthic comm...

  11. Microplastic in three urban estuaries, China.

    PubMed

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-11-01

    Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. PMID:26312741

  12. Proceedings of the 1st conference on nuclear structure data evaluation

    SciTech Connect

    Firestone, R.B.; Shirley, V.S.; Dairiki, J.M.

    1982-04-01

    The 1st Conference on Nuclear Structure Data Evaluation was organized by the Isotopes Project of the Lawrence Berkeley Laboratory in order to encourage the open discussion of the scientific aspects of ENSDF production and usage. Summaries of the roundtable discussion sessions, abstracts of the presented papers, and additional contributed papers are contained in these Proceedings.

  13. Mixing in the Amazon estuary

    NASA Astrophysics Data System (ADS)

    Bezerra, M. O.

    2010-05-01

    The research area of this work is located at the estuary of the Amazon River (Brazil), near the river mouth. The results of air movement analysis on the surface atmospheric circulation over the Mouth of the Amazonas River, salinity and temperature measures as well as measurements of currents, carried out along a longitudinal section in the navigation canal region of the Northern Bar of the Amazon River (Barra Norte do Rio Amazonas) in June 2006, during the river flood season in the quadrature tide. The dynamics effects affect hydrodynamic,meteorological and hydrographical parameters at the river mouth. The conclusion drawn include that: a) the saline wedge-type stratification can be detected approximately 100km away from the mouth of the Amazon River during the end of the rainy season in the quadrature tide; b) probably, at the Amazon estuary the quadrature entrainment processes are dominant and they are the ones responsible for increased salinity detected in the surface layer, whereas turbulence scattering mixing is not so important. c) The large flow of fresh water from the Amazon River at the end of the rainy season implies the displacement of the saline front position over the internal Amazon continental platform, and d) The tidal wave shows a positive asymmetry in the canal, with floods lasting less than in the ebb tide. This asymmetry decreases towards the ocean, eventually becoming reversed in the presence of a saline wedge. The speeds, however, have a negative asymmetry, with more intense ebb tides, due to the river flow and is more evident by the existence of quadrature tides.

  14. Estuaries.

    ERIC Educational Resources Information Center

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations designed to impart ocean understanding to high school students. When the student has completed this unit, he should be able to: (1) define an…

  15. Ernest Orlando Lawrence (1901-1958), Cyclotron and Medicine

    SciTech Connect

    Chu, William T.

    2005-09-01

    On August 8, 2001, Lawrence Berkeley National Laboratory celebrated the centennial of the birth of its founder (and namesake), Ernest Orlando Lawrence. For the occasion, many speeches were given and old speeches were remembered. We recall the words of the late Luis Alvarez, a Nobel Laureate and one of the Lawrence's closest colleagues: ''Lawrence will always be remembered as the inventor of the cyclotron, but more importantly, he should be remembered as the inventor of the modern way of doing science''. J. L. Heilbron and R. W. Seidel, in the introduction of their book, ''Lawrence and His Laboratory'' stated, ''The motives and mechanisms that shaped the growth of the Laboratory helped to force deep changes in the scientific estate and in the wider society. In the entrepreneurship of its founder, Ernest Orlando Lawrence, these motives, mechanisms, and changes came together in a tight focus. He mobilized great and small philanthropists, state and local governments, corporations, and plutocrats, volunteers and virtuosos. The work they supported, from astrophysics and atomic bombs, from radiochemistry to nuclear medicine, shaped the way we observe, control, and manipulate our environment.'' Indeed, all over the civilized world, the ways we do science changed forever after Lawrence built his famed Radiation Laboratory. In this editorial, we epitomize his legacy of changing the way we do medicine, thereby affecting the health and well being of all humanity. This year marks the 75th anniversary of the invention of the cyclotron by Ernest Orlando Lawrence at the University of California at Berkeley. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideroe on high-energy accelerators. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston, constructed a 13-cm diameter model that had all the features of early cyclotrons, accelerating protons to 80,000 volts using less than 1,000 volts on a semi-circular accelerating electrode, now called the ''dee''. Following the discovery by J. D. Cockcroft and E. T. S. Walton of how to produce larger currents at higher voltages, Lawrence constructed the first two-dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. The 27-Inch Cyclotron was used extensively in early investigations of nuclear reactions involving neutrons and artificial radioactivity. In 1939, working with William Brobeck, Lawrence constructed the 60-Inch (150-cm) Cyclotron, which accelerated deuterons to 19 MeV. It was housed in the Crocker Laboratory, where scientists first made transmutations of some elements, discovered several transuranic elements, and created hundreds of radioisotopes of known elements. At the Crocker Laboratory the new medical modality called nuclear medicine was born, which used radioisotopes for diagnosis and treatment of human diseases. In 1939 Lawrence was awarded the Nobel Prize in Physics, and later element 103 was named ''Lawrencium'' in his honor.

  16. A trophic model for the Danshuei River Estuary, a hypoxic estuary in northern Taiwan.

    PubMed

    Lin, Hsing-Juh; Shao, Kwang-Tsao; Jan, Rong-Quen; Hsieh, Hwey-Lian; Chen, Chang-Po; Hsieh, Li-Yung; Hsiao, Yi-Ting

    2007-11-01

    The estuary of the Danshuei River, a hypoxic subtropical estuary, receives a high rate of untreated sewage effluent. The Ecopath with Ecosim software system was used to construct a mass-balanced trophic model for the estuary, and network analysis was used to characterize the structure and matter flow in the food web. The estuary model was comprised of 16 compartments, and the trophic levels varied from 1.0 for primary producers and detritus to 3.0 for carnivorous and piscivorous fishes. The large organic nutrient loading from the upper reaches has resulted in detritivory being more important than herbivory in the food web. The food-chain length of the estuary was relatively short when compared with other tropical/subtropical coastal systems. The shortness of food-chain length in the estuary could be attributed to the low biomass of the top predators. Consequently, the trophic efficiencies declined sharply for higher trophic levels due to low fractions of flows to the top predators and then high fractions to detritus. The low biomass of the top predators in the estuary was likely subject to over-exploitation and/or hypoxic water. Summation of individual rate measurements for primary production and respiration yielded an estimate of -1791 g WW m(-2) year(-1), or -95 g C m(-2) year(-1), suggesting a heterotrophic ecosystem, which implies that more organic matter was consumed than was produced in the estuary. PMID:17826803

  17. The Estuary Book: A Guide to Promoting Understanding and Regional Management of Maine's Estuaries and Embayments.

    ERIC Educational Resources Information Center

    Ruffing, Jenny

    The objective of this document is to provide information about estuaries, the impact of uses on the environmental health of an estuary, and what communities and concerned individuals can do to manage and protect their local estuarine resources successfully. Much of the information presented here pertains to other embayments along the Maine coast…

  18. Polychlorinated biphenyl residues in some marine organisms from the Baie des Anglais (Baie-Comeau, Quebec, Saint-Lawrence Estuary

    SciTech Connect

    Delval, C.; Fournier, S.; Vigneault, Y.

    1986-12-01

    The main source of PCB's in the Baie des Anglais comes from a pseudo lagoon which is located upstream from the Anse au Moulin immediately below an aluminum plant. Organic matter in suspension coming from industrial wastes from baie-Comeau is likely responsible for the binding of PCB's. However due to hydrodynamic factors in the Baie des Anglais, contaminants stay only a short time in the littoral area and are evacuated to the southeast, where they accumulate at 80 m depth. Another source of contamination is the accumulation of dredging spoils at the entrance of the Anse au Moulin above the 40 m isobath. The contaminated sediments are resuspended by storm wave action. The work described in this paper was conducted in order to determine the extent of PCB bioaccumulation in two molluscs species (Mytilus edulis L. and Buccinum undatum L.) and two fish species (Clupea harengus harengus and Anguilla rostrata) from the Baie des Anglais (Baie-Comeau, Quebec).

  19. MOBILE BAY NATIONAL ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    In simplest terms, an estuary is defined as an area where rivers meet the sea. They are transitional zones where freshwater rivers meet tidally influenced marine waters. Estuaries are considered environmentally and economically important because of their exceptional biological di...

  20. Lawrence Berkeley Laboratory Institutional Plan FY 1995--2000

    SciTech Connect

    1994-12-01

    This report presents the details of the mission and strategic plan for Lawrence Berkeley Laboratory during the fiscal years of 1995--2000. It presents summaries of current programs and potential changes; critical success factors such as human resources; management practices; budgetary allowances; and technical and administrative initiatives.

  1. 78 FR 56609 - Drawbridge Operation Regulations; Reynolds Channel, Lawrence, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... Coast Guard is canceling the temporary deviation from the regulations published on June 11, 2013, (78 FR... new temporary deviation to include the bridge closures. DATES: The temporary deviation, (78 FR 34893... Channel, Lawrence, NY'', in the Federal Register (78 FR 34893). The temporary deviation concerned was...

  2. Management of hazardous wastes Lawrence Livermore National Laboratory

    SciTech Connect

    Jackson, C.S.

    1993-11-01

    Lawrence Livermore National Laboratory (LLNL), during the course of numerous research activities, generates hazardous, radioactive, and mixed (radioactive and hazardous) wastes. The management of these waste materials is highly regulated in the United States (US). This paper focuses on the hazardous waste regulations that limit and prescribe waste management at LLNL.

  3. LAWRENCE AVENUE UNDERFLOW SEWER SYSTEM: MONITORING AND EVALUATION

    EPA Science Inventory

    A new and bold concept in design of urban drainage systems was developed as a step forward in the solution of combined sewer overflow problems. A deep tunnel in bed rock about 200 to 250 feet (61 to 76 m) below the surface was designed and constructed for the Lawrence Avenue drai...

  4. LAWRENCE AVENUE UNDERFLOW SEWER SYSTEM. INTERIM REPORT: PLANNING AND CONSTRUCTION

    EPA Science Inventory

    A new and bold concept in design of urban drainage systems was developed as a step forward in the solution of combined sewer overflow problems. A deep tunnel in bed rock about 200 to 250 feet (61 to 76 m) below the surface was designed and constructed for the Lawrence Avenue drai...

  5. Copyright in the Balance: LJ Talks with Lawrence Lessig.

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard

    2002-01-01

    Discusses copyright issues of interest to librarians with Lawrence Lessig, a legal scholar on copyright, technology, and the Constitution. Topics include Eldred v. Ashcroft; copyright extensions; balancing interests of copyright owners with future creators and the public; privacy, fair use, and public domain; and the Digital Millennium Copyright…

  6. Jacob Lawrence's "The Migration Series": Art as Narrative History

    ERIC Educational Resources Information Center

    Laney, James D.

    2007-01-01

    Because art is a reflection of cultural heritage, a natural affinity exists between art and social studies. In Jacob Lawrence's "The Migration Series," art serves as narrative history, with visual images telling the story of the Great Migration, a movement of African American people from the South to the North around World War I. Social studies…

  7. Copyright in the Balance: LJ Talks with Lawrence Lessig.

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard

    2002-01-01

    Discusses copyright issues of interest to librarians with Lawrence Lessig, a legal scholar on copyright, technology, and the Constitution. Topics include Eldred v. Ashcroft; copyright extensions; balancing interests of copyright owners with future creators and the public; privacy, fair use, and public domain; and the Digital Millennium Copyright

  8. Jacob Lawrence's "The Migration Series": Art as Narrative History

    ERIC Educational Resources Information Center

    Laney, James D.

    2007-01-01

    Because art is a reflection of cultural heritage, a natural affinity exists between art and social studies. In Jacob Lawrence's "The Migration Series," art serves as narrative history, with visual images telling the story of the Great Migration, a movement of African American people from the South to the North around World War I. Social studies

  9. Waste management study: Process development at Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1984-12-01

    This report presents the results of an evaluation of the present Toxic Waste Control Operations at the Lawrence Livermore National Laboratory, evaluates the technologies most applicable to the treatment of toxic and hazardous wastes and presents conceptual designs of processes for the installation of a new decontamination and waste treatment facility (DWTF) for future treatment of these wastes.

  10. Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1986

    SciTech Connect

    Schleimer, G.E.

    1987-04-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1986 are presented and general trends are discussed. Topics include radiation monitoring, wastewater discharge monitoring, dose distribution estimates, and ground water monitoring. 9 refs., 8 figs., 20 tabs.

  11. PHOTOCOPY OF HISTORIC PHOTOGRAPH, "LAWRENCE LEVERING BECKEL (BRIDGE BUILT BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOCOPY OF HISTORIC PHOTOGRAPH, "LAWRENCE LEVERING BECKEL (BRIDGE BUILT BY HIM AND HIS FATHER, CHAS. N. BECKEL AT EASTON)," original ca. 1885, photographer unknown. Collection of Historic Bethlehem Inc., Bethlehem, PA, Negative Nos. 3550 or 4504. - Walnut Street Bridge, Formerly spanning Saucon Creek, Hellertown, Northampton County, PA

  12. DASLL: design automation system at Lawrence Livermore. User's reference manual

    SciTech Connect

    Magnuson, W.G. Jr.; Willett, G.W.

    1980-04-01

    This manual shows how to use the DASLL system to lay out printed circuit boards using the OCTOPUS CDC 7600 computer system and other equipment at Lawrence Livermore Laboratory. This information will also be found very useful for those converting or analyzing the DASLL system.

  13. Environmental monitoring at the Lawrence Livermore Laboratory. 1979 annual report

    SciTech Connect

    Silver, W.J.; Lindeken, C.L.; White, J.H.; Buddemeir, R.W.

    1980-04-25

    Information on monitoring activities is reported in two sections for EDB/ERA/INIS. The first section covers all information reported except Appendix D, which gives details of sampling and analytical procedures for environmental monitoring used at Lawrence Livermore Laboratory. A separate abstract was prepared for Appendix D. (JGB)

  14. Estuaries and coastal waters need help

    SciTech Connect

    Levenson, H.

    1987-11-01

    For years, our marine environments-estuaries, coastal waters, and the open ocean-have been used extensively by coastal communities and industries for the disposal of various wastes. Historically, marine waste disposal has been relatively cheap and has solved some short-term waste-management problems; however, its consequences include a general trend toward environmental degradation, particularly in estuaries and coastal waters. Thus, without protective measures, the next few decades will witness degradation in many estuaries and some coastal waters around the country. The extent of current degradation varies greatly around the country. Although it is difficult to ascertain cause and effect relationships, enough evidence exists to conclude that the pollutants in question include disease-causing microorganisms, oxygen-demanding substances, particulate material, metals, and organic chemicals. Two statutes form the basis of most federal regulatory efforts to combat marine pollution: the Marine Protection, Research, and Sanctuaries Act (MPRSA) and the Clean Water Act (CWA). The MPRSA regulates the dumping of wastes in coastal and open-ocean waters, whereas the CWA has jurisdiction over pipeline discharges in all marine waters, wastes dumped in estuaries, and runoff. Many people consider that the passage and implementation of these two acts and their ensuing amendments established a statutory structure sufficient to protect the nation's waters from pollution. However, these provisions have not protected some estuaries and coastal waters from degradation.

  15. Environmental flow assessments for transformed estuaries

    NASA Astrophysics Data System (ADS)

    Sun, Tao; Zhang, Heyue; Yang, Zhifeng; Yang, Wei

    2015-01-01

    Here, we propose an approach to environmental flow assessment that considers spatial pattern variations in potential habitats affected by river discharges and tidal currents in estuaries. The approach comprises four steps: identifying and simulating the distributions of critical environmental factors for habitats of typical species in an estuary; mapping of suitable habitats based on spatial distributions of the Habitat Suitability Index (HSI) and adopting the habitat aggregation index to understand fragmentation of potential suitable habitats; defining variations in water requirements for a certain species using trade-off analysis for different protection objectives; and recommending environmental flows in the estuary considering the compatibility and conflict of freshwater requirements for different species. This approach was tested using a case study in the Yellow River Estuary. Recommended environmental flows were determined by incorporating the requirements of four types of species into the assessments. Greater variability in freshwater inflows could be incorporated into the recommended environmental flows considering the adaptation of potential suitable habitats with variations in the flow regime. Environmental flow allocations should be conducted in conjunction with land use conflict management in estuaries. Based on the results presented here, the proposed approach offers flexible assessment of environmental flow for aquatic ecosystems that may be subject to future change.

  16. The ecological condition of Veracruz, Mexico estuaries.

    PubMed

    Macauley, J M; Harwell, L C; Alafita, H V

    2007-10-01

    During June and July, 2002, forty-seven stations were sampled within estuaries along the gulf coast of the state of Veracruz, MX, using a probabilistic survey design and a common set of response indicators. The objective of the study was to collect information to assess the condition of estuarine waters within the state of Veracruz, and to provide data that would strengthen future assessments of Gulf of Mexico estuaries. Samples for water quality, sediment contaminants, sediment toxicity, and benthic populations were collected in a manner consistent with EPA's National Coastal Assessment (NCA). Data were evaluated by comparing indicator measurements to tropical waters threshold values cited in US EPA's National Coastal Condition Report II, 2004, for tropical waters. In Veracruz, 75% of the area sampled rated poor for water quality, attributed primarily to high concentrations reported for chlorophyll a, and dissolved nutrients. One percent of the area exhibited poor sediment quality, based on PAH and metals concentrations. Compared to US estuaries of the Gulf of Mexico, water quality observed in Veracruz estuaries was more affected by nutrient over-enrichment. The probabilitistic nature of the survey design allowed for the comparison of the condition of Veracruz and the US GOM estuaries. PMID:17295108

  17. Prediction in ungauged estuaries: An integrated theory

    NASA Astrophysics Data System (ADS)

    Savenije, Hubert H. G.

    2015-04-01

    Many estuaries in the world are ungauged. The International Association of Hydrological Sciences completed its science decade on Prediction in Ungauged Basins (PUB) in 2012 (Hrachowitz et al.). Prediction on the basis of limited data is a challenge in hydrology, but not less so in estuaries, where data on fundamental processes are often lacking. In this paper, relatively simple, but science-based, methods are presented that allow researchers, engineers, and water managers to obtain first-order estimates of essential process parameters in estuaries, such as the estuary depth, the tidal amplitude, the tidal excursion, the phase lag, and the salt water intrusion, on the basis of readily obtainable information, such as topographical maps and tidal tables. These apparently simple relationships are assumed to result from the capacity of freely erodible water bodies to adjust themselves to external drivers and to dissipate the free energy from these drivers as efficiently as possible. Thus, it is assumed that these systems operate close to their thermodynamic limit, resulting in predictable patterns that can be described by relatively simple equations. Although still much has to be done to develop an overall physics-based theory, this does not prevent us from making use of the empirical "laws" that we observe in alluvial estuaries.

  18. SAN FRANCISCO ESTUARY PROJECT COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    The Estuary, a significant natural resource, San Francisco Bay and the Delta combine to form the West Coast's largest estuary. The Estuary conveys the waters of the Sacramento and San Joaquin Rivers to the Pacific Ocean. It encompasses roughly 1,600 square miles, drains over 40 p...

  19. The Estuary Guide. Level 3: High School. Draft.

    ERIC Educational Resources Information Center

    Alexander, Glen; And Others

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

  20. Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA

    NASA Astrophysics Data System (ADS)

    Buzzelli, C.; Wan, Y.; Doering, P. H.; Boyer, J. N.

    2013-10-01

    Interactions among geomorphology, circulation, and biogeochemical cycling determine estuary responses to external nutrient loading. In order to better manage watershed nutrient inputs, the goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River estuary (CRE) and the St. Lucie Estuary (SLE), from 2002 to 2008. The Land-Ocean Interactions in the Coastal Zone (LOICZ) approach was used to generate water, salt, and DIN and DIP budgets. Results suggested that internal DIN production increases with increased DIN loading to the CRE in the wet season. There were hydrodynamic effects as water column concentrations and ecosystem nutrient processing stabilized in both estuaries as flushing time increased to >10 d. The CRE demonstrated heterotrophy (net ecosystem metabolism or NEM < 0.0) across all wet and dry season budgets. While the SLE was sensitive to DIN loading, system autotrophy (NEM > 0.0) increased significantly with external DIP loading. This included DIP consumption and a bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge to the SLE in 2005. Additionally, while denitrification provided a microbially-mediated N loss pathway for the CRE, this potential was not evident for the SLE where N2 fixation was favored. Disparities between total and inorganic loading ratios suggested that the role of dissolved organic nitrogen (DON) should be assessed for both estuaries. Nutrient budgets indicated that net internal production or consumption of DIN and DIP fluctuated with inter- and intra-annual variations in freshwater inflow, hydrodynamic flushing, and primary production. The results of this study should be included in watershed management plans in order to maintain favorable conditions of external loading relative to internal material cycling in both dry and wet seasons.

  1. Using side-scan sonar to characterize and map physical habitat and anthropogenic underwater features in the St. Louis River.

    EPA Science Inventory

    Characterizing underwater habitat and other features is difficult and costly, especially in the large St. Louis River Estuary. We are using side-scan sonar (SSS), first developed in the 1960s to remotely sense underwater habitat features from reflected acoustic signals (backscatt...

  2. From "Lawrence Kohlberg's Approach to Moral Education" by F. Clark Power, Ann Higgins, and Lawrence Kohlberg, with Judy Codding (1989)

    ERIC Educational Resources Information Center

    Schools: Studies in Education, 2011

    2011-01-01

    This article is an excerpt from "Lawrence Kohlberg's Approach to Moral Education." It refers several times to Kohlberg's "six stages of moral development." Stages 3 and 4 belong to the second level of moral development, which Kohlberg calls "conventional." At stage 3, one becomes aware of conventions as one sees what is right in terms of living up…

  3. Modeling tidal distortion in the Ogeechee Estuary

    NASA Astrophysics Data System (ADS)

    Bruder, Brittany; Bomminayuni, Sandeep; Haas, Kevin; Stoesser, Thorsten

    2014-10-01

    A 3D numerical model is used to simulate the distortion of tidal hydrodynamics in the Ogeechee Estuary, GA. The Ogeechee, like many estuaries found in the Southeastern US, consists of shallow channel networks and extensive intertidal storage in the form of wetlands. Such features are known to induce non-linear overtide generation and significant tidal distortion, otherwise known as tidal stage asymmetry. Simulations are run with varying parameters to assess their effects on modeling tidal distortion for the Ogeechee Estuary: bottom friction coefficients, enhanced wetland friction coefficients, and tidal flat elevations. To succinctly quantify the degree of distortion across the domain, the statistical parameters of skewness and asymmetry are calculated for time series of water surface heights and channel volume fluxes. The intertidal storage causes the peak flood flux to occur later and the peak ebb flux to occur earlier, thereby resulting in positive asymmetry for the volume flux for the full estuary. However, ebb dominance is a localized feature and varies throughout the estuary. Increasing the intertidal storage by lowering wetland elevation enhances the effects on high tide and volume flux magnitudes, decreasing the ebb-dominance and volume flux asymmetry typically associated with intertidal storage thereby indicating the importance of the wetland elevation over the total storage volume. Increased channel bottom friction reduces ebb-dominance by extending the duration of the falling tide. More interestingly, increased wetland friction reduces the influence of wetland intertidal storage on tidal distortion. The model suggests an increase in wetland friction does little to dampen wave propagation at high tide but rather impedes the lateral flooding of wetlands, reducing ebb dominance. Tidal flat elevation has the largest impact on distortion for the Ogeechee Estuary whereas enhanced wetland and bottom frictional influences on distortion are small, albeit not insignificant.

  4. St. John's Wort (image)

    MedlinePlus

    The herb St. John's Wort is believed to be helpful in relieving mild to moderate depression, but should only be taken under a physician's supervision. St. John's Wort may clash with other medications or foods ...

  5. D.H. Lawrence and the Dialogical Principle: "The Strange Reality of Otherness."

    ERIC Educational Resources Information Center

    Sargent, M. Elizabeth; Watson, Garry

    2001-01-01

    Focuses on D.H. Lawrence and his being taken seriously as an original thinker. Notes that Lawrence is thought of primarily as a novelist. Suggests that readers should acknowledge Lawrence as an original thinker in an evolving history of the dialogical principle and in a continuing attempt to understand the dialogical and its political and ethical…

  6. Missouri: St. Louis

    Atmospheric Science Data Center

    2014-05-15

    ... to the east, on the Illinois side, are highlighted with green vegetation. Meandering rivers in the verdant Ozark Plateau appear to the ... nearby Kirkwood, Webster Groves, Clayton, University City, Ferguson, St. Ann, St. Charles, and East St. Louis. The region is home to ...

  7. 75 FR 1010 - CSX Transportation, Inc.-Discontinuance of Service Exemption-in Clark, Floyd, Lawrence, Orange...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ..., Floyd, Lawrence, Orange, and Washington Counties, IN On December 18, 2009, CSX Transportation, Inc... Albany, in Clark, Floyd, Lawrence, Orange, and Washington Counties, IN.\\1\\ The line traverses...

  8. National estuary program guidance: Technical characterization in the National Estuary Program

    SciTech Connect

    Not Available

    1994-06-01

    Estuaries are waterways, such as bays and sounds, where fresh water drained from the surrounding watershed mixes with salt water from the ocean. Section 320 of the Clean Water Act established the National Estuary Program (NEP) to identify nationally significant estuaries threatened by pollution, development, or overuse and to promote the preparation of comprehensive management plans to ensure their ecological integrity. The program's goals are protection and improvement of water quality and enhancement of living resources. To reach these goals, the Administrator of the U.S. Environmental Protection Agency (EPA) convenes management conferences for each estuary in the NEP to provide a forum for consensus building and problem solving among interested agencies and user groups.

  9. PECONIC ESTUARY: AN ASSESSMENT OF SHELLFISH RESOURCES IN THE TRIBUTARIES AND EMBAYMENTS OF THE PECONIC ESTUARY

    EPA Science Inventory

    Executive Summary Historically, the Peconic Estuary's shellfish resources have supported significant fisheries for a number of species including hard clams, oysters and bay scallops. However, distribution and abundance data for the tributaries and embayments within the Peconic Es...

  10. Lawrence Berkeley Laboratory magnetic-moment sorting system

    NASA Astrophysics Data System (ADS)

    Nelson, D. H.; Barale, P. J.; Green, M. I.; Vandyke, D. A.

    1985-07-01

    The Magnetic Measurements Engineering Group at Lawrence Berkeley Laboratory (LBL) has designed and built, and is currently using, a Magnetic-moment Measurement and Sorting System (MMSS). The MMSS measures magnetic moments of permanent-magnet material and sorts the material according to selected criteria. The MMSS represents the latest application of the LBL General Purpose Magnetic Measurement Data Acquisition System reported on a MT-8. We describe the theoretical basis for the MMSS, the analog and digital components, and a unique method of calibrating the MMSS using only measured electrical quantities. We also discuss the measurement and sorting of permanent-magnet material to be incorporated in beam-line elements (dipoles and quadrupoles) in the Lawrence Livermore National Laboratory Advanced Test Accelerator Beam Director.

  11. Annual site environmental report of the Lawrence Berkeley Laboratory

    SciTech Connect

    Schleimer, G.E.; Pauer, R.O.

    1991-05-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1990 are presented, and general trends are discussed. The report is organized under the following topics: Environmental Program Overview; Environmental Permits; Environmental Assessments; Environmental Activities; Penetrating Radiation; Airborne Radionuclides; Waterborne Radionuclides; Public Doses Resulting from LBL Operations; Trends -- LBL Environmental Impact; Waterborne Pollutants; Airborne Pollutants; Groundwater Protection; and Quality Assurance. 20 refs., 26 figs., 23 tabs.

  12. Making Sense of the Senseless: The Murder of Lawrence King

    ERIC Educational Resources Information Center

    Reis, Beth

    2008-01-01

    On Feb. 12, 2008, 15-year-old Lawrence King was shot twice in the head in front of other students, in Oxnard, California. When Larry King was murdered allegedly due to a classmate's prejudice, some pundits asked if adults were to blame for encouraging him to come out. One can't be sure what adults did or didn't do in this case, but the question…

  13. Catalog of research projects at Lawrence Berkeley Laboratory, 1985

    SciTech Connect

    Not Available

    1985-01-01

    This Catalog has been created to aid in the transfer of technology from the Lawrence Berkeley Laboratory to potential users in industry, government, universities, and the public. The projects are listed for the following LBL groups: Accelerator and Fusion Research Division, Applied Science Division, Biology and Medicine Division, Center for Advanced Materials, Chemical Biodynamics Division, Computing Division, Earth Sciences Division, Engineering and Technical Services Division, Materials and Molecular Research Division, Nuclear Science Division, and Physics Division.

  14. Astronomy Applications of Adaptive Optics at Lawrence Livermore National Laboratory

    SciTech Connect

    Bauman, B J; Gavel, D T

    2003-04-23

    Astronomical applications of adaptive optics at Lawrence Livermore National Laboratory (LLNL) has a history that extends from 1984. The program started with the Lick Observatory Adaptive Optics system and has progressed through the years to lever-larger telescopes: Keck, and now the proposed CELT (California Extremely Large Telescope) 30m telescope. LLNL AO continues to be at the forefront of AO development and science.

  15. Industrial ecology at Lawrence Livermore National Laboratory summary statement

    SciTech Connect

    Gilmartin, T.J.

    1996-05-21

    This statement summarizes Lawrence Livermore National Laboratory`s committment to making important scientific, technological, and business contributions to global sustainability. The quest has many aspects, some socio-political or economic and some technological, and some in which the soft and hard sciences become indistinguishable, as in visionary national strategies, like Holland`s, and futuristic regional and city development plans, like those of Kagoshima and Chattanooga.

  16. Application of optical interconnect technology at Lawrence Livermore National Laboratory

    SciTech Connect

    Haigh, R.E.; Lowry, M.E.; McCammon, K.; Hills, R.; Mitchell, R.; Sweider, D.

    1995-08-10

    Optical interconnects will be required to meet the information bandwidth requirements of future communication and computing applications. At Lawrence Livermore National Laboratory, the authors are involved in applying optical interconnect technologies in two distinct application areas: Multi-Gigabit/sec Computer Backplanes and Gigabit/sec Wide Area Networking using Wavelength Division Multiplexing. In this paper, the authors discuss their efforts to integrate optical interconnect technologies into prototype computing and communication systems.

  17. MODELING FINE SEDIMENT TRANSPORT IN ESTUARIES

    EPA Science Inventory

    A sediment transport model (SEDIMENT IIIA) was developed to assist in predicting the fate of chemical pollutants sorbed to cohesive sediments in rivers and estuaries. Laboratory experiments were conducted to upgrade an existing two-dimensional, depth-averaged, finite element, coh...

  18. Kaua'i: Streams and Estuaries.

    ERIC Educational Resources Information Center

    Hawkins, John, Ed.; Murakami, Colleen, Ed.

    Designed to help teachers develop students' awareness and understanding of some of Hawaii's endangered aquatic resources, this module contains activities and instructional suggestions for use with intermediate as well as high school students. The module is divided into two sections which explore the streams and estuaries of Kauai. Activities in…

  19. Climate change and its impacts on estuaries

    EPA Science Inventory

    Past, present, and future research by WED scientists in the TEP region will be described to lay the foundation for examination of potential climate change effects on estuaries and the broader coastal zone in the Pacific Northwest (PNW). Results from National Coastal Assessments,...

  20. Bacterioplankton dynamics in the Mondego estuary (Portugal)

    NASA Astrophysics Data System (ADS)

    Bacelar-Nicolau, P.; Nicolau, L. B.; Marques, J. C.; Morgado, F.; Pastorinho, R.; Azeiteiro, U. M.

    2003-05-01

    In this work, the density of bacterioplankton and environmental parameters were monitored over a 11 month period (July 1999-June 2000), and also during one tidal cycle (15 June 2000), at two sampling stations, in the estuary of River Mondego. These data were treated by multivariate analyses methods in order to identify the key factors that control the dynamics of the bacterioplankton in the estuary. Bacterial dynamics were dominated by temporal gradients (annual seasons and tide-related) and less by the spatial structure of the estuary. Three main metabolic groups of bacterioplankton—aerobic heterotrophic bacteria, sulphate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB)—involved in the cycling of organic matter, were present in the water column of the estuary. Their relative abundance depended on the particular physical, chemical and biological environment. The abundance of aerobic heterotrophic bacteria, during the 11 month study, was modelled as a function of nitrate (the most important variable, with a negative effect), temperature, salinity and pH (with positive effects). SRB appeared to be limited to the water-sediment interface, where concentrations of sulphate and POM were greater. A competition between SRB and NRB for carbon has also been suggested.

  1. VOLUNTEER ESTUARY MONITORING: A METHOD MANUAL

    EPA Science Inventory

    Executive Summary: This manual focuses on volunteer estuary monitoring. As concern over the well-being of the environment has increased during the past couple of decades, volunteer monitoring has become an integral part of the effort to assess the health of our nation’s wat...

  2. Restoration of the Golden Horn Estuary (Halic).

    PubMed

    Coleman, Heather M; Kanat, Gurdal; Aydinol Turkdogan, F Ilter

    2009-12-01

    Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes. PMID:19781731

  3. THE ECOLOGICAL CONDITION OF VERACRUZ, MEXICO ESTUARIES

    EPA Science Inventory

    During June and July, 2002, forty-seven stations were sampled within estuaries along the gulf coast of the state of Veracruz, MX, using a probabilistic survey design and a common set of response indicators. The objective of the study was to collect information to assess the condi...

  4. Padilla Bay: The Estuary Guide. Level 2.

    ERIC Educational Resources Information Center

    Friesem, Judy; Lynn, Valerie, Ed.

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the middle school level is designed for use with the on-site program developed by the Padilla Bay National Esturine Research Reserve (Washington). The guide…

  5. Listening to Estuary English in Singapore

    ERIC Educational Resources Information Center

    Deterding, David

    2005-01-01

    In Singapore, many people are not familiar with Estuary English (EE), the variety of English becoming popular in much of southern England. In the current study, when students listened to interviews with EE speakers and were asked to transcribe orthographically what they heard, most of them had severe problems. Features of pronunciation that…

  6. Estuaries and Tidal Marshes. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

  7. Mercury pollution in the Ems estuary

    NASA Astrophysics Data System (ADS)

    Essink, K.

    1980-03-01

    From approximately 1960 to 1975 the Ems estuary received several tons of mercury per year from a chlor-alkali plant, a pesticide factory and some minor sources. The discharge has been reduced drastically from 1976 onwards. In 1975 and 1976 measurements were made on the distribution of mercury in the sediment. The horizontal distribution revealed a strong local enrichment of the sediment near the point of discharge. The vertical distribution was found to be in accordance with the local deposition rates. In the water phase no significant change in mercury content from 1975 to 1978/79 could be demonstrated. In 1978/79 a difference between Ems estuary and Dutch Wadden Sea was not significant. In 1978 mercury contents of eelpout Zoarces viviparus in the Ems estuary were about twice as high as in the Wadden Sea. In the Ems estuary a decrease of these contents was found between 1974/75 and 1978. A similar decline in the Wadden Sea may be related to a decreased mercury discharge by the River Rhine.

  8. BCG Approaches for Improved Management of Estuaries

    EPA Science Inventory

    Estuaries and other complex aquatic systems are exposed to a variety of stressors that act at several scales, but are managed piecemeal - - often resulting in a “death by 1000 cuts” caused by cumulative impacts to these valued resources. To address this, managers need tools that...

  9. DELAWARE ESTUARY PROGRAM IMPLEMENTATION STREAMLINE REVIEW, 2002

    EPA Science Inventory

    The primary purpose of the Delaware Estuary Program implementation review (formerly known as the biennial review) has been to assist EPA in. making funding decisions for those NEPs that are in the post-CCMP, or implementation, phase, and to evaluate implementation progress. The i...

  10. INDICATORS OF ECOSYSTEM INTEGRITY FOR ESTUARIES

    EPA Science Inventory

    Jordan, Stephen J. and Lisa M. Smith. In press. Indicators of Ecosystem Integrity for Estuaries. In: Proceedings of the Estuarine Indicators Workshop, 29-31 October 2003, Sanibel Island, FL. Sanibel-Captiva Conservation Foundation, Sanibel, FL. 23 p. (ERL,GB 1194).

    Ideal ...

  11. Trace metal sources in two Malaysian estuaries

    SciTech Connect

    Nelson, B.W.; Kahn, I.S.A.

    1985-01-01

    The natural background concentrations of trace metals associated with suspended sediments in the non-urbanized upper reaches of the Kelang, Selangor, and Linggi rivers (West Malaysia) have been determined. These watersheds are underlain by weathered granite and covered, generally, by tropical jungle. The mean trace metal concentrations of the sediments in ..mu..-g/g are: Mn, 396; Zn, 92; Pb, 74; Cu, 24; Cr, 37; Ni, 21, and V, 45. These values are low compared to those reported from river sediments in North American and Europe. The spectra of trace metal abundances of the suspended sediments are very similar to the spectrum of source area granites. Thus, the granites impose a strong provenance control, in spite of intense weathering processes that have converted primary minerals to clay. Suspended sediments in the non-urbanized Selangor estuary have the same trace metal concentrations as above and exhibit no effects due to human activities. Suspended sediments in the Kelange estuary show Cu, Zn, and Pb concentrations of nearly three times the natural background levels and comparable to values reported from river sediments in North America and Europe. This estuary receives inputs from the urbanized area of Kuala Lumpur and the industrialized lower Kelang valley. Pb concentrations in the estuary are higher than for many northern hemisphere rivers. Furthermore, its concentration in the tributary sediments is higher than in the source area granites. This suggests airborne dispersal of Pb from the urban source and concentration in the suspended sediments.

  12. Nutrient elements in large Chinese estuaries

    NASA Astrophysics Data System (ADS)

    Zhang, Jing

    1996-07-01

    Based on comprehensive observations since 1983, this study summarizes major features of nutrient elements (nitrogen, phosphorus and silicon) in large Chinese river/estuary systems. Elevated nutrient element levels were observed in Chinese rivers, when compared to large and less disturbed aquatic systems (e.g. the Amazon, Zaire and Orinoco). Data from this study are similar to those obtained from the polluted and/or eutrophic rivers in Europe and North America (e.g. the Rhóne and Loire). Nutrient elements may have either conservative or active distributions, or both, in the mixing zone, depending on the element and the estuary. For example, non-conservative behaviors were observed in the upper estuary, where nutrient elements may be remobilized due to the strong desorption and variations of the fresh water end-member, but conservative distributions were found afterwards in the lower estuary. Outside the riverine effluent plumes, nutrient elements may be depleted in surface waters relative to elevated bioproduction, whereas the regeneration with respect to decomposition of organic material and/or nitrification/denitrification offshore, may sustain high levels of nutrient elements in near-bottom waters. Laboratory experiment data generally compares well with field observations. The high fluxes and area] yields of nutrient elements from large Chinese rivers, indicate the extensive use of chemical fertilizers and domestic waste drainage over watersheds in China.

  13. Predicting Bankfull Discharge in Ungauged Estuaries by Explaining the Physical Relation Between the Morphology and Hydrology of Estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, J.; Savenije, H.

    2013-12-01

    River discharge is a very important parameter in morphological and hydrodynamic studies of estuaries. However, it is always difficult to accurately measure river discharge, and in particular the bankfull discharge in estuaries where the tidal discharge dominates over river discharge. Until today, little research has been done in finding a simple and useful approach to estimate the river discharge in the tidal region, and most of the previous studies focused on the river regime. In this study, we found that there appear to be empirical relations that link together the morphology and hydrology of estuaries, which can be used to estimate river discharge with the least amount of data available. The aims of this study are: 1) to discover the physical explanation for the empirical relation that exists between geometrical characteristics of estuaries and the bankfull flood discharge; and 2) to estimate bankfull discharge in estuaries from the relationship. The physical connection between the estuaries and river regime is found by incorporating the estuary shape analysis and tidal dynamic analysis to Lacey's hydraulic geometry theory. Relationship between the estuary depth and the bankfull river discharge has been analyzed in 19 estuaries around the world (with 9 recently surveyed estuaries). In this study, the discharge data (from gauging station located further upstream) were adjusted by a projection approach to improve the discharge measurement. The outcome of the relationship was compared to Lacey's theory of hydraulic geometry. From the analysis, it shows that the depth of an estuary is a function of the bankfull flood discharge to the power of 1/3 which indicates an agreement with Lacey's formula. With the physical explanation, engineers would be able to estimate flood discharge characteristics from estuary shape indicators. This could be very useful to estimate the flood discharge in ungauged estuaries on the basis of readily available data. In order to verify the accuracy of the relation, existing and new measurement data from estuaries worldwide will be collected and compiled to strengthen the reliability of this finding.

  14. Fish composition and assemblage structure in three Eastern English Channel macrotidal estuaries: A comparison with other French estuaries

    NASA Astrophysics Data System (ADS)

    Selleslagh, Jonathan; Amara, Rachid; Laffargue, Pascal; Lesourd, Sandric; Lepage, Mario; Girardin, Michel

    2009-01-01

    This study has analysed for the first time fish composition and assemblage structures of three small macrotidal estuaries of the Eastern English Channel (EEC) and has explored the influences of 19 biotic and abiotic variables on the fish assemblages. Fish from Canche, Authie and Somme estuaries were collected during spring (June 2006 and May 2007) and autumn (September 2006) along the estuarine gradients using a 1.5 m beam trawl. Using identical sampling protocols, the study also analysed and compared for the first time taxonomic and functional aspects of the fish assemblages in 15 estuaries located along the Atlantic and English Channel coasts. SIMPER analysis showed high similarities in fish assemblages in the three EEC estuaries and during either spring or autumn periods. However, intra-estuary similarities were relatively low, indicating that fish assemblage structures (species richnesses or abundances) were more variable within the estuary (salinity gradient) than between estuaries and/or seasons (spring vs autumn). Although numerous environmental variables were included in the study, only 47% of the variability observed in the fish distribution was explained. Fish spatial variations in the EEC estuaries are mostly driven by abiotic variables as opposed to biological interactions. As indicated by CCA, salinity and muddy sediments were the two most important factors structuring the fish assemblages. The macrobenthos being very abundant in the EEC estuaries (580-1121 ind. m -2), the availability of potential prey is probably not a limiting factor in the utilization of estuaries by fish. Contrary to the majority of French estuaries dominated by estuarine species (ES), the fish assemblages of the EEC estuaries are clearly dominated by marine migrant (MM) species (65% on average) with high abundance of juveniles (mostly young-of-the-year). Cluster and SIMPROF's analyses distinguished the functional structure of the 15 estuarine fish assemblages into different clusters. The three EEC estuaries form a similar group with the largest French estuaries (Seine, Loire and Gironde). The latters were characterized by higher MM/ES ratio compared to the other French estuaries. Freshwater flow and tidal range were the main factors associated with this group of estuaries. The results of the present study do not indicate that anthropogenic impacts (chemical contamination) on estuaries affect their ecological functioning as described by the fish ecological guilds. It is suggested that the guild approach may not be useful to provide valuable information on the ecological status of estuaries.

  15. Historical changes in the Columbia River Estuary

    NASA Astrophysics Data System (ADS)

    Sherwood, Christopher R.; Jay, David A.; Bradford Harvey, R.; Hamilton, Peter; Simenstad, Charles A.

    Historical changes in the hydrology, sedimentology, and physical oceanography of the Columbia River Estuary have been evaluated with a combination of statistical, cartographic, and numerical-modelling techniques. Comparison of data digitized from US Coast and Geodetic Survey bathymetric surveys conducted in the periods 1867-1875, 1926-1937, and 1949-1958 reveals that large changes in the morphology of the estuary have been caused by navigational improvements (jetties, dredged channels, and pile dikes) and by the diking and filling of much of the wetland area. Lesser changes are attributable to natural shoaling and erosion. There has been roughly a 15% decrease in tidal prism and a net accumulation of about 68 × 10 6m 3 of sediment in the estuary. Large volumes of sediment have been eroded from the entrance region and deposited on the continental shelf and in the balance of the estuary, contributing to formation of new land. The bathymetric data indicate that, ignoring erosion at the entrance, 370 to 485 × 10 6m 3 of sediment has been deposited in the estuary since 1868 at an average rate of about 0.5 cm y -1, roughly 5 times the rate at which sea level has fallen locally since the turn of the century. Riverflow data indicate that the seasonal flow cycle of the Columbia River has been significantly altered by regulation and diversion of water for irrigation. The greatest changes have occurred in the last thirty years. Flow variability over periods greater than a month has been significantly damped and the net discharge has been slightly reduced. These changes in riverflow are too recent to be reflected in the available in the available bathymetric data. Results from a laterally averaged, multiple-channel, two-dimensional numerical flow model (described in HAMILTON, 1990) suggest that the changes in morphology and riverflow have reduced mixing, increased stratification, altered the response to fortnightly (neap-spring) changes in tidal forcing, and decreased the salinity intrusion length and the transport of salt into the estuary. The overall effects of human intervention in the physical processes of the Columbia River Estuary (i.e. decrease in freshwater inflow, tidal prism, and mixing; increase in flushing time and fine sediment deposition, and net accumulation of sediment) are qualitatively similar to those observed in less energetic and more obviously altered estuarine systems. A concurrent reduction in wetland habitats has resulted in an estimated 82% reduction in emergent plant production and a 15% reduction in benthic macroalgae production, a combined production loss of 51,675 metric tons of organic carbon per year. This has been at least partially compensated by a large increase in the supply of riverine detritus derived from freshwater phytoplankton primary production. Comparison of modern and estimated preregulation organic carbon budgets for the estuary indicates a shift from a food web based on comparatively refractory macrodetritus derived from emergent vegetation to one involving more labile microdetritus derived from allochthonous phytoplankton. The shift has been driven by human-induced changes to the physical environment of the estuary. While this is a relatively comprehensive study of historical physical changes, it is incomplete in that the sediment budget is still uncertain. More precise quantification of the modern estuarine sediment budget will require both a better understanding of the fluvial input and dredging export terms and a sediment tranport model designed to explain historical changes in the sediment budget. Oceanographic studies to better determine the mechanisms leading to the formation of the turbidity maximum are also needed. The combination of cartography and modelling used in this study should be applicable in other systems where large changes in morphology have occurred in historical time.

  16. Second International Symposium on the Biogeochemistry of Model Estuaries: Estuarine processes in global change. Final report

    SciTech Connect

    Windom, H.L.

    1991-12-31

    This report summarizes estuary events discussed at the symposium on biogeochemistry. Topics include; sedimentation, salinity, inputs and outputs of the estuary, effects of global change, and the need for effective sampling and modeling of estuaries.

  17. Iron isotope fractionation in subterranean estuaries

    NASA Astrophysics Data System (ADS)

    Rouxel, Olivier; Sholkovitz, Edward; Charette, Matthew; Edwards, Katrina J.

    2008-07-01

    Dissolved Fe concentrations in subterranean estuaries, like their river-seawater counterparts, are strongly controlled by non-conservative behavior during mixing of groundwater and seawater in coastal aquifers. Previous studies at a subterranean estuary of Waquoit Bay on Cape Cod, USA demonstrate extensive precipitation of groundwater-borne dissolved ferrous iron and subsequent accumulation of iron oxides onto subsurface sands. Waquoit Bay is thus an excellent natural laboratory to assess the mechanisms of Fe-isotope fractionation in redox-stratified environments and determine potential Fe-isotope signatures of groundwater sources to coastal seawater. Here, we report Fe isotope compositions of iron-coated sands and porewaters beneath the intertidal zone of Waquoit Bay. The distribution of pore water Fe shows two distinct sources of Fe: one residing in the upward rising plume of Fe-rich groundwater and the second in the salt-wedge zone of pore water. The groundwater source has high Fe(II) concentration consistent with anoxic conditions and yield ?56Fe values between 0.3 and -1.3. In contrast, sediment porewaters occurring in the mixing zone of the subterranean estuary have very low ?56Fe values down to -5. These low ?56Fe values reflect Fe-redox cycling and result from the preferential retention of heavy Fe-isotopes onto newly formed Fe-oxyhydroxides. Analysis of Fe-oxides precipitated onto subsurface sands in two cores from the subterranean estuary revealed strong ?56Fe and Fe concentration gradients over less than 2m, yielding an overall range of ?56Fe values between -2 and 1.5. The relationship between Fe concentration and ?56Fe of Fe-rich sands can be modeled by the progressive precipitation of Fe-oxides along fluid flow through the subterranean estuary. These results demonstrate that large-scale Fe isotope fractionation (up to 5) can occur in subterranean estuaries, which could lead to coastal seawater characterized by very low ?56Fe values relative to river values.

  18. A predictive model for salt intrusion in estuaries applied to the Yangtze estuary

    NASA Astrophysics Data System (ADS)

    Cai, Huayang; Savenije, Hubert H. G.; Zuo, Shuhua; Jiang, Chenjuan; Chua, Vivien P.

    2015-10-01

    Understanding the way salinity distribution in an estuary reacts to external drivers (e.g., tide, fresh water discharge, dredging, etc.) is important for both water quality and water resources management in estuaries. The salinity distribution depends strongly on the geometry of an estuary, but also on the fresh water discharge that counteracts the salt intrusion. In estuaries it is notoriously hard to estimate this discharge and subsequently to predict the parameters that determine the mixing behaviour depending on it. Recently a method has been developed to predict the fresh water discharge on the basis of water level observations. In addition, predictive equations for tidal mixing have been updated and revised. In this paper, these two predictive methods are combined and subsequently applied to the Yangtze estuary under a wide variation of fresh water discharge. The predicted salt distribution appears to be in good agreement with observations. To provide insight into the optimum use of water resources (e.g., to determine the amount of fresh water discharge required to maintain a specific salt intrusion length), we further study the salt intrusion pattern under different tide and fresh water discharge conditions.

  19. Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)

    NASA Astrophysics Data System (ADS)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Reny, P. D.; Deepak, M. P.; Muraleedharan, K. R.; Naveen Kumar, K. R.

    2013-01-01

    The intratidal, spring-neap and seasonal variations in stratification were examined in the Cochin estuary. The observations established a strong connection with the distribution of chemical and biological properties. The influence of tides and river discharge forcing in water column stability was quantified using potential energy anomaly (PEA) and stratification parameter. Partially mixed (neap) and well-mixed (spring) conditions during low river discharge (dry) period were altered in monsoon by the salt wedge intrusions. The ecological impact of salt wedge propagation on high tides bringing upwelled water to the system was evident from the bottom hypoxic, high chlorophyll a and nutrient-rich conditions. Phosphate and nitrite concentrations were higher at the bottom saline conditions but silicate and nitrate were clearly supplied by river water. However, during ebb tide this front was driven out of the estuary. The periodic advance and retreat of the salt wedge was inevitable in making the system immune from extended hypoxia/anoxia and maintaining the health of the Cochin estuary. For the seasonally varying river flow in the estuary, salt intrusion receded with increasing river flow in monsoon and rebounded with decreasing river flow in dry season. During monsoon, the intense flushing and reduction in salinity field expansion seemed to be responsible for the limited chlorophyll a levels along the surface of the Cochin estuary.

  20. Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)

    NASA Astrophysics Data System (ADS)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Reny, P. D.; Deepak, M. P.; Muraleedharan, K. R.; Naveen Kumar, K. R.

    2012-07-01

    The intratidal, spring-neap and seasonal variations in stratification were examined in Cochin estuary. The observations established a strong connection with the distribution of chemical and biological properties. The influence of tides and river discharge forcing in water column stability was quantified using potential energy anomaly (PEA) and stratification parameter. Partially mixed (neap) and well-mixed (spring) conditions during low river discharge (dry) period were altered in monsoon by the salt wedge intrusions. The ecological impact of salt wedge propagation on high tides bringing upwelled water to the system was evident from the bottom hypoxic, high chlorophyll a and nutrient-rich conditions. Phosphate and nitrite concentrations were higher at the bottom saline conditions but silicate and nitrate were clearly supplied by river water. However, during ebb tide this front was driven out of the estuary. The periodic advance and retreat of the salt wedge was inevitable in making the system immune from extended hypoxia/anoxia and maintaining the health of Cochin estuary. For the seasonally varying river flow in the estuary, salt intrusion receded with increasing river flow in monsoon and rebounded with decreasing river flow in dry season. During monsoon, the intense flushing and reduction in salinity field expansion seemed to be responsible for the limited chlorophyll a levels along the surface of Cochin estuary.

  1. Benthic primary production in the Columbia River Estuary. Final report

    SciTech Connect

    McIntire, C.D.; Amspoker, M.C.

    1984-02-01

    The general objective of the research associated with the Benthic Primary Production Work Unit of Columbia River Estuary Development Program was to determine mechanisms that control the production dynamics and species composition of benthic plant assemblages in the Columbia River Estuary. In particular, the work was concerned with effects of selected physical variables on structural and functional attributes of micro- and macro- vegetation, and on the productivity and biomass of benthic autotrophs on the tidal flats of the estuary.

  2. Tiger Team Assessment of the Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1990-06-01

    This report documents the results of the Tiger Team Assessment of the Lawrence Livermore National Laboratory (LLNL) (including the Site 300 area), Livermore, California, conducted from February 26 to April 5, 1990. The purpose of the assessment was to provide the Secretary of Energy with the status of Environment, Safety and Health (E SH) Programs at LLNL. LLNL is operated by the University of California for the Department of Energy (DOE), and is a multi-program, mission-oriented institution engaged in fundamental and applied research programs that require a multidisciplinary approach. The Tiger Team Assessment was conducted by a team comprised of professionals from DOE, contractors, and consultants.

  3. Precision and manufacturing at the Lawrence Livermore National Laboratory

    SciTech Connect

    Saito, T.T.; Wasley, R.J.; Stowers, I.F.; Donaldson, R.R.; Thompson, D.C.

    1993-11-01

    Precision Engineering is one of Lawrence Livermore National Laboratory`s core strengths. This paper discusses the past and present current technology transfer efforts of LLNL`s Precision Engineering program and the Livermore Center for Advanced Manufacturing and Productivity (LCAMP). More than a year ago the Precision Machining Commercialization project embodied several successful methods of transferring high technology from the National Laboratories to industry. Currently LCAMP has already demonstrated successful technology transfer and is involved in a broad spectrum of current programs. In addition this paper discusses other technologies ripe for future transition including the Large Optics Diamond Turning Machine.

  4. Precision and manufacturing at the Lawrence Livermore National Laboratory

    NASA Technical Reports Server (NTRS)

    Saito, Theodore T.; Wasley, Richard J.; Stowers, Irving F.; Donaldson, Robert R.; Thompson, Daniel C.

    1994-01-01

    Precision Engineering is one of the Lawrence Livermore National Laboratory's core strengths. This paper discusses the past and present current technology transfer efforts of LLNL's Precision Engineering program and the Livermore Center for Advanced Manufacturing and Productivity (LCAMP). More than a year ago the Precision Machine Commercialization project embodied several successful methods of transferring high technology from the National Laboratories to industry. Currently, LCAMP has already demonstrated successful technology transfer and is involved in a broad spectrum of current programs. In addition, this paper discusses other technologies ripe for future transition including the Large Optics Diamond Turning Machine.

  5. Storm water modeling at Lawrence Livermore National Laboratory

    SciTech Connect

    Veis, Christopher

    1996-05-01

    Storm water modeling is important to Lawrence Livermore National Laboratory (LLNL) for compliance with regulations that govern water discharge at large industrial facilities. Modeling is also done to study trend in contaminants and storm sewer infrastructure. The Storm Water Management Model (SWMM) was used to simulate rainfall events at LLNL. SWMM is a comprehensive computer model for simulation of urban runoff quantity and quality in storm and combined sewer systems. Due to time constraints and ongoing research, no modeling was completed at LLNL. With proper information about the storm sewers, a SWMM simulation of a rainfall event on site would be beneficial to storm sewer analyst.

  6. Technical Safety Appraisal of the Lawrence Livermore National Laboratory

    SciTech Connect

    Not Available

    1990-12-01

    This report documents the results of the Technical Safety Appraisal (TSA) of the Lawrence Livermore National Laboratory (LLNL) (including the Site 300 area), Livermore, California, conducted from February 26 to April 5, 1990. The purpose of the assessment was to provide the Secretary of Energy with the status of Environment, Safety and Health (ES H) Programs at LLNL. LLNL is operated by the University of California for the Department of Energy (DOE), and is a multi-program, mission-oriented institution engaged in fundamental and applied research programs that require a multidisciplinary approach. 1 fig.

  7. USING DOE-2.1 AT LAWRENCE BERKELEY LABORATORY

    SciTech Connect

    Building Energy Analysis Group.; Authors, Various

    1980-09-01

    The purpose of this manual is to assist the DOE-2 user to run DOE-2 and its utility programs at Lawrence Berkeley Laboratory (LBL). It is organized to reflect the facts that every DOE-2 job run at LBL requires certain steps, and that there are options related to DOE-2 job runs available to any DOE-2 user. The standard steps for running a DOE-2 job are as follows: 1. Prepare a job deck 2. Process a job deck 3. Obtain standard output reports.

  8. Annual environmental monitoring report of the Lawrence Berkeley Laboratory

    SciTech Connect

    Schleimer, G.E.

    1989-06-01

    The Environmental Monitoring Program of the Lawrence Berkeley Laboratory (LBL) is described. Data for 1988 are presented and general trends are discussed. In order to establish whether LBL research activities produced any impact on the population surrounding the laboratory, a program of environmental air and water sampling and continuous radiation monitoring was carried on throughout the year. For 1988, as in the previous several years, dose equivalents attributable to LBL radiological operations were a small fraction of both the relevant radiation protection guidelines (RPG) and of the natural radiation background. 16 refs., 7 figs., 21 tabs.

  9. Lawrence Berkeley National Laboratory 1995 site environmental report

    SciTech Connect

    Balgobin, D.; Javandel, I.; Lackner, G.; Smith, C.; Thorson, P.; Tran, H.

    1996-07-01

    The 1995 Site Environmental Report summarizes environmental activities at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) for the 1995 calendar year. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the environmental management programs. The report also discusses significant highlights and plans of these programs. Topics discussed include: environmental monitoring, environmental compliance programs, air quality, water quality, ground water protection, sanitary sewer monitoring, soil and sediment quality, vegetation and foodstuffs monitoring, and special studies which include preoperational monitoring of building 85 and 1995 sampling results, radiological dose assessment, and quality assessment.

  10. Laser guide star measurements at Lawrence Livermore National Laboratory

    SciTech Connect

    Friedman, H.; Avicola, K.; Bissinger, H.; Brase, J.; Duff, J.; Gavel, D.; Horton, J.; Max, C.; Olivier, S.; Rapp, D.; Salmon, T.; Smauley, D.; Waltjen, K.

    1993-02-01

    Recent studies from the Laser Guide Star Project at Lawrence Livermore National Laboratory are presented. Photometry of the return signal has shown that the photon return is approximately 10 photons/cm{sup 2}ms at the pupil of the receiving telescope in agreement with a detailed model of the sodium interaction. Wavefronts of the laser guide star have also been measured with a Shack-Hartmann technique and power spectra have been shown to agree with those of nearby natural stars. Plans for closed loop demonstrations using the laser guide star at LLNL and nearby Lick Observatory are discussed.

  11. Impact of Recent Constraints on Intellectual Freedom on Science and Technology at Lawrence Livermore National Laboratory

    SciTech Connect

    Wadsworth, J

    2000-11-12

    The Lawrence Livermore National Laboratory (LLNL) was created in 1952 to meet the nation's need for an expanded nuclear weapons research and development (R&D) capability. LLNL quickly grew to become a full-fledged nuclear weapons design laboratory with a broad range of technical capabilities similar to those of our sister laboratory--Los Alamos--with which we shared mission responsibilities. By its very nature, nuclear weapons R&D requires some of the most advanced science and technology (S&T). Accordingly, there is an obvious need for careful attention to ensure that appropriate security measures exist to deal with the sensitive aspects of nuclear weapons development. The trade-off between advancing S&T at the Laboratory and the need for security is a complex issue that has always been with us, As Edward Teller noted in a recent commentary in a May, 1999 editorial in the New York Times: ''The reaction of President Harry Truman to the leaking of information is well known. He imposed no additional measures for security. Instead, we have clear knowledge that the disclosures by (Klaus) Fuchs caused Truman to call for accelerated work on all aspects of nuclear weapons. The right prescription for safety is not reaction to dangers that are arising, but rather action leading to more knowledge and, one hopes, toward positive interaction between nations.'' To explore the issue of intellectual freedom at a national security laboratory such as LLNL, one must understand the type of activities we pursue and how our research portfolio has evolved since the Laboratory was established. Our mission affects the workforce skills, capabilities, and security measures that the Laboratory requires. The national security needs of the US have evolved, along with the S&T community in which the Laboratory resides and to which it contributes. These factors give rise to a greater need for the Laboratory to interact with universities, industry, and other national laboratories. Intellectual freedom at the Laboratory and constraints on it can be understood only within the context of our mission, our necessary interactions with other entities; and our need for an exceptional multidisciplinary workforce.

  12. Impact of climate change on Gironde Estuary

    NASA Astrophysics Data System (ADS)

    Laborie, Vanessya; Hissel, François; Sergent, Philippe

    2014-05-01

    Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

  13. Mercury biogeochemical cycling in a stratified estuary

    SciTech Connect

    Mason, R.P.; Fitzgerald, W.F. ); Hurley, J. ); Hanson, A.K. Jr.; Donaghay, P.L.; Sieburth, J.M. )

    1993-09-01

    Total Hg in the permanently stratified Pettaquamscutt estuary was <25 pM throughout the water column, even in highly sulfidic bottom waters. Particulate Hg was typically >40% of the total Hg. Reactive Hg (Hg[sub R]) was generally <3 pM and decreased with depth, but there is Hg[sub R] even in the anoxic bottom waters. Elemental Hg (Hg[sup 0]) was highest in the mixed layer and below the detection limit at depth. Demethylation is not an important source of Hg[sup 0] in this estuary. Dimethylmercury was not detected. Monomethylmercury (MMHg) was near the detection limit in the mixed layer and increased rapidly in the low oxygen region. Dissolved MMHg correlated with bacteriochlorophyll pigments, suggesting that the microbial community plays an important role in MMHg production in the estuary. The overall distributions of dissolved and particulate Hg species result from the interaction with Fe and Mn redox cycling, particulate scavenging and sinking, and MMHg production in the pycnocline. The estimated rate of MMHg production from Hg[sub R] in the pycnocline region is 1.7% d[sup [minus]1]. Hg[sup 0] and MMHg are formed principally in the mixed layer and in the pycnocline region, respectively. Particulate scavenging is important, and sedimentation, methylation, and Hg[sup 0] production are the principal sinks for Hg[sub R].

  14. St. John's Wort

    MedlinePlus

    ... for more information. St. John’s wort is a plant with yellow flowers whose medicinal uses were first recorded in ancient Greece. The name St. John’s wort apparently refers to John the Baptist, as the plant blooms around the time of the feast of ...

  15. 21st Century Scholars

    ERIC Educational Resources Information Center

    Clark, Terrence

    2009-01-01

    Bethpage Union Free School District in New York is a high-performing district by almost any current accountability measure. Yet administrators and teachers worried that they were not doing enough to prepare their students as critical thinkers for the 21st century. Inspired by the curriculum framework of the Partnership for 21st Century Skills, the…

  16. Current Characterization at the Amazon estuary

    NASA Astrophysics Data System (ADS)

    Bezerra, M. O.

    2009-04-01

    At the estuary there are several mechanisms that cause turbulence: influence of solid contours (estuary bottom and shores), speed vertical shearing (fluid inside), wind shearing stress (free surface) and surface and internal gravity waves. Turbulence intensity controls vertical distribution of estuary water mass property concentration. As flow into the estuary takes place during the transition or turbulent regimen, produced by small space and time scale movements, entrainment, turbulent scattering and advection are the processes responsible for fresh water mixing up with the sea and for local salinity variation, as well as for concentration of natural properties and man-made ones. According to this focus, we shall describe general circulation, conveyance and mixing characteristics of the Amazon low estuary waters. Amazon estuary shows unusual characteristics: it is of vast length and enormous outflow. It is extremely wide - 150 Km - and its discharge into the Atlantic amounts to 180,000 m3s-1 (Otman, 1968, Figueiredo et al, 1991), which means 18% of all water discharged by rivers into oceans; this is the largest punctual source of fresh water for oceans (Milliman and Meade, 1983). Maximum outflow is 2.5 x 105 m3s-1, and it happens at the end of May. Minimum outflow is 1.2 x 105 m3 s-1, and it takes place in November. At Amazon River, the Mixing Zone occurs where the Coastal Zone usually is. The reason for that is the extension of fresh water plume moves Northeast for over 1000 Km (Gibbs, 1970; Muller-Karger et al 1988). This is the most extensive estuarine plume ever found in the ocean. During low fluvial discharge (June-November) plume reaches 300 Km; however, on high discharge (November-May) plume reaches 500 Km. Plume already is 3 to 10 m thick and 80 to 300 Km wide (Lentz and Limeburner, 1995). From June to January plume moves towards Africa, from whence 70% of it goes east carried by North Brazil Current retroflection and 30% goes towards the Caribbean. From February to May, the plume goes northwest towards the Caribbean. As to classification according to salinity stratification, at the quadrature the Amazon estuary is considered as "Saline Wedge" type (highly stratified estuary), salinity at 120 Km way from river moth standing out, whereas at sysygy it can be classified as well mixed (Limeburner et al. 1991e 1992; Patchineelam, 2004). Fresh water is everywhere in the river area, salty or mixed water is located in the ocean. In this estuary 90 Km away from the mouth surface water salinity is less than 0.05 and bottom salinity at 14 m deep is about 19 at high water on quadrature at the end of the rainy season. This behavior produces marked difference in the vertical salinity profile, showing the current is moving in the opposite direction (river fresh water and salty water brought by the tide). In this scenario, speed shearing at the interface produces interfacial friction stress that, from the entrainment process carries portions of water from the sea to the upper part. Usually, therefore, in "saline wedge" (highly stratified estuary) type estuaries, when river discharge is more intensive than the tide wave, entrainment is the predominant mechanism; and the greater tide amplitude is, the greater will its influence be to produce turbulent scattering and mixing be. Probably, at Amazon estuary quadrature entrainment processes are predominant and are the ones responsible for increased salinity in surface layer, whereas turbulence scattering mixing is secondary to it. "Saline wedge" (highly stratified estuary) type estuaries are typical of large fluvial discharge and microtide regions. But although the Amazon estuary is a macrotide region, this stratification is due to the river's exceptional discharge. Due to the remarkable river plume discharge on the platform, the tide - a dominant in macrotide region estuarine circulation - now has a secondary role, albeit not a negligible one, with quadrature amplitudes varying from 2 m to 90 Km from the mouth. It is important to point out that tide-induced mixing processes determine saline front position and structure. The circulation pattern is bidirectional: at the surface layer near river mouth, medium current flows perpendicular to isobates towards the sea, turning north until it starts to flow parallel to the continent. At the lower layer near river mouth, current flows towards the continent. At the upper layer one finds more intensive tidal current (Gibbs, 1982). Flow is weak at the bottom, showing shoreward movement under the plume that moves towards the platform. Great speed shearing is compensated by high salinity stratification at the middle of the water column and by the high concentration of sediments (fluid mud) near ocean bed (Geyer e Kineke, 1995). As for the behavior of tide-produced currents, the main tide forcing mechanism is semidiurnal (a 12.4-hour period), M2 component predominating, which in its turn is influenced by Amazon Continental Platform morphology, which breaks at the 100 m isobate. This Platform width varies significantly along the coast from 125 km to 325 km, which causes tide semidiurnal components to be enlarged at some points. North Cabo Norte, platform extension is less than at the mouth; thus, M2 travels as a stationary wave due to the near-resonant character present in coastal embayments between Cabo Norte and Cabo Cassiporé. Near the mouth M2 travels as a progressive wave due to its convergent character, whose amplitude decreases and phase grows upstream. (Beardsley et al). Tide amplitude at the coast is usually about 5 m; however, it is possible to find tide channels of up to 14 m (Vinzon, S. spoken lecture). Tide wave propagation along the channel makes the wave to be laterally compressed by river shores; however, friction exceeds convergence and causes tide height to decrease along the channel, it then being classified as a hyposynchronous estuary. At maximum outflow dynamic tide travels to the neighborhood of Gurupa Island and, at minimum outflow, dynamic tide travels to Óbidos, 840 Km upstream the river mouth (Ferraz 1975; Vinzon el al, 2007). Tide current speed component condemned axles show up in the river channel and up to about 70 Km from the mouth, that is, at the Platform, having an alternative and axial character and ebb and flood, and at more than 90 Km from the mouth tide ellipse axles tend to a rotating patter, always keeping, however, a greater axle aligned to channel configuration (Gallo et al, 2007 and Pontes, 2007). Tide speed components show quite an energetic behavior, being able to reach speeds over 2 m/s. Tide currents - usually perpendicular to the coast - vary from 200 cm/s at high tides to 80 cm/s at ebb tide in mouth neighborhood. Once tides are removed, residual currents show strong shearing, with surface speeds over 100 cm/s (Geyer and Kineke, 1995). Tide shows asymmetry, taking 4-5 hours to flood and 8-9 hours to ebb. If time intervals between ebb and flood differ, it follows from the volume conservation principle that during the shorter event - such as at Amazon estuary flood tide - speed shall be greater; as a consequence, suspended sediment transportation shall be greater during flood in comparison to ebb, assuming adequate sediment/water supply at both events. This is not to say, however, that at Amazon estuary speed shall be greater during ebb, for the large river outflow is added to ebb currents. The Amazon estuary is a peculiar case: albeit flood time is less than ebb one, the estuary is dominated by ebb tide, becoming a sediment exporter (Vinzón, et al 2007). The Amazon River discharges 3 million tons a day of sediments into the Amazon Continental Platform (Nittrouer et al 1986). These sediments are deposited NW of the outfall; there then happens a concentration rate of sediments in layers ("fluid mud") about 4 m thick in contact with sea bed (Geuer and Kineke, 1995). Fluid mud concentration is 10g/l of sediment.

  17. Mercury in sediments of Ulhas estuary.

    PubMed

    Ram, Anirudh; Rokade, M A; Borole, D V; Zingde, M D

    2003-07-01

    Hg levels in water, suspended particulate matter and sediment of the Ulhas estuary are under considerable environmental stress due to the indiscriminate release of effluents from a variety of industries including chlor-alkali plants. Concentration ranges of dissolved (0.04-0.61 micro gl(-1)) and particulate (1.13-6.43 micro gg(-1)) Hg reveal a definite enhancement of levels in the estuary. The Hg burden in sediment upstream of the weir that limits the tidal influence is low (0.08-0.19 micro gg(-1)) with low C(org) content (1.8-2.9%). The high Hg content of the sediment just below the weir varies seasonally (highest concentration recorded being 38.45 micro gg(-1)) due to incremental accretion of sediment as the fresh water flow over the weir progressively decreases. The 30 km segment of the estuary sustains markedly high levels of Hg in the sediment with an exponential decrease in the seaward direction from the weir. Higher concentrations than the expected background prevail in all the estuarine cores up to the bottom, though the overall concentration decreases from about 20 micro gg(-1) in core 7 (inner estuary) to 1 micro gg(-1) in core 31 (outer estuary). The Hg in sediment is associated with C(org), while its correlation with Al, Fe and Mn is poor. The Hg profiles in cores from the Arabian Sea (stations 34, 35 and 37) have a distinct horizon of enhanced concentration in the 5-60 cm segment. Based on 210Pb dating of core 37, the sediment at the bottom of this core is inferred to have been deposited in the year 1949, roughly two year prior to the establishment of the first chlor-alkali plant and represents the background (0.06-0.10 micro gg(-1)). The Hg profiles in the offshore cores indicate a marked increase in transfer of Hg to sediment subsequent to 1980, with a peak around 1990-1992. Based on the index of geoaccumulation it is considered that the estuarine segment between stations 4 and 23 is extremely polluted, while the sediment from the open coast is moderately polluted in the top 25-30 cm with respect to Hg. The enrichment factor of Hg in the sediment is 350-700 for core 4 and decreases to 0-7 for the open-shore cores. PMID:12837303

  18. Freshwater, tidal and wave influences on a small estuary

    NASA Astrophysics Data System (ADS)

    Uncles, R. J.; Stephens, J. A.; Harris, C.

    2014-10-01

    Observations are presented of water levels, currents, salinity, turbidity, sediment grain sizes and sediment transport in the Devonshire Avon Estuary, UK, in order to improve knowledge of freshwater, wave and tidal influences on small, strongly tidal ría estuaries. A large reduction in tidal range occurred progressing from the coastal zone to the upper estuary that was mainly a consequence of rising bed and river water levels. The spring-neap cycle also had an influence on the reduction in tidal range along the length of the estuary. Surface gravity waves were completely dissipated propagating into the estuarine channel from the coastal zone, and despite strong wave-induced resuspension, suspended sediment was not transported into the lower estuary in observable amounts during the ensuing flood tide, indicating that the wave-suspended material was too coarse to remain in suspension once transported away from the surf zone. Turbidity in the lower estuary was relatively low during low runoff summer conditions and had largest values over low water, when turbid waters from farther up-estuary had been transported there. Strong resuspension events occurred at peak currents in the upper estuary during summer, reflecting the presence of finer-grained sediment sources. Turbidity was similar but greater in the lower estuary during high runoff winter conditions and strong resuspension occurred at peak currents, indicating an easily erodible, nearby sediment source, due to down-estuary movement and relocation of finer sediment over the winter. A large shoal in the lower estuary exhibited a consistent pattern of accretion/erosion during the high runoff months of late autumn and winter to spring that also was qualitatively consistent with sediment transport modelling and implied: (a), erosion from the up-estuary limit of the shoal with (b), down-estuary bed-load and suspended-load transport that accreted the centre and down-estuary limit of the shoal until (c), a diminished supply led to erosion via continued down-estuary transport from the shoal centre.

  19. ASSESSING THE ECOLOGICAL CONDITION OF SOUTHEAST U. S. ESTUARIES

    EPA Science Inventory

    As a means to assess ecological condition, 151 stations located in southeastern estuaries from Cape Henry, Virginia to Biscayne Bay, Florida were sampled by state agencies during the summer of 2000 using a probabilistic design. The design used 8 size classes of estuaries ranging ...

  20. YAQUINA BAY AND BEYOND: WHAT SHAPE ARE OUR ESTUARIES IN?

    EPA Science Inventory

    The great natural beauty of Oregon's estuaries gives an impression of systems that are far less altered than those in other areas of the US. However, over the years, Yaquina Bay and other western estuaries have been variously affected by habitat loss and alteration, over harvest...

  1. FROM LANDSCAPE ECOLOGY OF WATERSHEDS TO BENTHIC ECOLOGY OF ESTUARIES

    EPA Science Inventory

    Do land use/cover characteristics of watersheds associated with small estuaries (<260 km2) have a strong enough signal to make landscape metrics useful for finding impaired bottom communities? We tested this idea with 58 pairs of small estuaries and watersheds from Delaware Bay t...

  2. Identifying and organizing objectives across the 28 National Estuary Programs

    EPA Science Inventory

    The National Estuary Program (NEP), established in 1987 by amendments to the Clean Water Act, is intended to support local communities to restore, protect and manage estuaries of national significance. Currently there a 28 NEPs spread widely across the U.S. and its territories. E...

  3. Trace metal concentrations in estuaries and coastal regions

    SciTech Connect

    Hunt, C.D.

    1994-12-31

    Estuaries and coastal regions are highly variable in the physical and hydrographic conditions. As a result of heavy urbanization and industrialization of the head waters of most estuaries, there are substantial localized inputs of contaminants to the estuary. These factors combined with the flushing characteristics of individual estuaries to create relatively unique features that result in variation in the typical levels of trace metals for these systems. This makes intercomparison of the estuaries difficult. Comparability among estuaries becomes even more difficult when metals analyses are conducted without proper control of field and laboratory contamination, now firmly established in the trace metal analytical literature as a prerequisite for reliable marine trace metals analysis. This paper compares the concentrations of selected trace metal (Ag, Cd, Cu, Ni, Pb, and Zn) concentrations in the waters of several major estuaries of the United States. The basis of comparison is that all samples war collected under rigid trace metal clean collection and analysis procedures. Generally, metal concentrations within the estuaries are similar. Metal concentrations in the higher salinity coastal regions are more similar in concentration. The comparison provides a baseline of typical concentrations of these trace metals in the coastal waters against which future analytical results can be compared.

  4. PECONIC ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    The Peconic Estuary, situated between the North and South Forks of eastern Long Island, New York, consists of more than 100 distinct bays, harbors, embayments, and tributaries. The area surrounding the Peconic Estuary's watershed is rich in rolling farmland, scenic beaches and cr...

  5. LOWER COLUMBIA RIVER ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

    EPA Science Inventory

    An estuary is the area where the fresh water of a river meets the salt water of an ocean. In the Columbia River system, this occurs in the lower 46 river miles. In an estuary, the river has a direct, natural connection with the open sea. This transition from fresh to salt water c...

  6. Macroalgae, pore water sulfides and eelgrass in Yaquina estuary, Oregon

    EPA Science Inventory

    The hypothesis that relatively high nutrients in estuaries of the Pacific Northwest (PNW) can lead to eutrophication and degradation of critical eelgrass habitat was examined. Yaquina estuary was surveyed for cover and above-ground biomass of benthic macroalgae (Ulva spp.) and n...

  7. Nitrogen Source and Loading Data for EPA Estuary Data Mapper

    EPA Science Inventory

    Nitrogen source and loading data have been compiled and aggregated at the scale of estuaries and associated watersheds of the conterminous United States, using the spatial framework in EPA's Estuary Data Mapper (EDM) to provide system boundaries. Original sources of data include...

  8. ECOLOGICAL CONDITION OF ESTUARIES IN THE GULF OF MEXICO

    EPA Science Inventory

    The predominantly shallow estuaries in the Gulf of Mexico are ranked highest in the Nation in terms of water surface area, freshwater inflow, and wetlands area. Estuaries are an ecologically and economically valuable resource in the Gulf of Mexico. The U.S. Environmental Protecti...

  9. WATER QUALITY MODELING IN THE RIO CHONE ESTUARY

    EPA Science Inventory

    Water quality in the Rio Chone Estuary, a seasonally inverse, tropical estuary, in Ecuador was characterized by modeling the distribution of biochemical oxygen demand (BOD) and dissolved inorganic nitrogen (DIN) within the water column. These two variables are modeled using modif...

  10. PECONIC ESTUARY: RECREATIONAL AND RESOURCE ECONOMIC VALUES FOR THE PECONIC ESTUARY SYSTEM

    EPA Science Inventory

    The environmental and natural resources ("natural assets") of the Peconic Estuary System--the bay waters, beaches, wetlands, ecosystems, habitats, and parks and watershed lands--provide many services to the public. Outdoor recreation, scenic views, and the productivity of wetland...

  11. Approaches for Development of Nutrient Criteria in Oregon Estuaries With a Focus on Tillamook Estuary

    EPA Science Inventory

    Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

  12. Conditions for tidal bore formation in convergent alluvial estuaries

    NASA Astrophysics Data System (ADS)

    Bonneton, Philippe; Filippini, Andrea Gilberto; Arpaia, Luca; Bonneton, Natalie; Ricchiuto, Mario

    2016-04-01

    Over the last decade there has been an increasing interest in tidal bore dynamics. However most studies have been focused on small-scale bore processes. The present paper describes the first quantitative study, at the estuary scale, of the conditions for tidal bore formation in convergent alluvial estuaries. When freshwater discharge and large-scale spatial variations of the estuary water depth can be neglected, tide propagation in such estuaries is controlled by three main dimensionless parameters: the nonlinearity parameter ε0 , the convergence ratio δ0 and the friction parameter ϕ0. In this paper we explore this dimensionless parameter space, in terms of tidal bore occurrence, from a database of 21 estuaries (8 tidal-bore estuaries and 13 non tidal-bore estuaries). The field data point out that tidal bores occur for convergence ratios close to the critical convergence δc. A new proposed definition of the friction parameter highlights a clear separation on the parameter plane (ϕ0,ε0) between tidal-bore estuaries and non tidal-bore estuaries. More specifically, we have established that tidal bores occur in convergent estuaries when the nonlinearity parameter is greater than a critical value, εc , which is an increasing function of the friction parameter ϕ0. This result has been confirmed by numerical simulations of the two-dimensional Saint Venant equations. The real-estuary observations and the numerical simulations also show that, contrary to what is generally assumed, tide amplification is not a necessary condition for tidal bore formation. The effect of freshwater discharge on tidal bore occurrence has been analyzed from the database acquired during three long-term campaigns carried out on the Gironde/Garonne estuary. We have shown that in the upper estuary the tidal bore intensity is mainly governed by the local dimensionless tide amplitude ε. The bore intensity is an increasing function of ε and this relationship does not depend on freshwater discharge. However, freshwater discharge damps the tidal wave during its propagation and thus reduces ε and consequently limits the tidal bore development in the estuary. To take into account this process in the tidal-bore scaling analysis, it is necessary to introduce a fourth external parameter, the dimensionless river discharge Q0 .

  13. Lawrence Livermore National Laboratory environmental report for 1990

    SciTech Connect

    Sims, J.M.; Surano, K.A.; Lamson, K.C.; Balke, B.K.; Steenhoven, J.C.; Schwoegler, D.R.

    1990-01-01

    This report documents the results of the Environmental Monitoring Program at the Lawrence Livermore National Laboratory (LLNL) and presents summary information about environmental compliance for 1990. To evaluate the effect of LLNL operations on the local environment, measurements of direct radiation and a variety of radionuclides and chemical compounds in ambient air, soil, sewage effluent surface water, groundwater, vegetation, and foodstuff were made at both the Livermore site and at Site 300 nearly. LLNL's compliance with all applicable guides, standards, and limits for radiological and nonradiological emissions to the environment was evaluated. Aside from an August 13 observation of silver concentrations slightly above guidelines for discharges to the sanitary sewer, all the monitoring data demonstrated LLNL compliance with environmental laws and regulations governing emission and discharge of materials to the environment. In addition, the monitoring data demonstrated that the environmental impacts of LLNL are minimal and pose no threat to the public to or to the environment. 114 refs., 46 figs., 79 tabs.

  14. The Greening of the David L. Lawrence Pittsburgh Convention Center

    NASA Astrophysics Data System (ADS)

    Leahy, Mark

    2009-03-01

    The David L. Lawrence Convention Center is the largest Gold LEED NC (new construction) certified convention center in the USA and the first of its kind in the world. The designation has been awarded by the United States Green Building Council through its Leadership in Energy and Environmental Design (LEED) Green Building Rating System. In this talk we discuss the unique green properties of this 1.5 million square foot Convention Center including the design and use of daylight, natural ventilation and other sustainable design and practices. No other building the size of the Convention Center (1.5 million square feet), uses natural ventilation or can illuminate an exhibition hall entirely through its windows and skylights. Approximately 75% of the convention center's exhibition space is lit by natural daylight. The use of natural ventilation and extensive day lighting is designed to reduce energy consumption by nearly 35% compared to traditional ventilated and lit buildings of a similar size.

  15. Lawrence Berkeley Laboratory Self-Assessment Program: Implementation Plan

    SciTech Connect

    Not Available

    1992-06-01

    The Lawrence Berkeley Laboratory (LBL) Self-Assessment Program provides a formal process for assuring quality and regulatory compliance in all facets of Laboratory operations. The program, which integrates the ongoing self-assessment activities of the individual Divisions and Offices in a comprehensive, top-to-bottom process, provides assistance to the US Department of Energy (DOE), the University of California, and Laboratory management in their appraisals of Laboratory performance. This document describes the program goals, scope, responsibilities, elements, and implementation schedule. This document is also the implementation plan for the institutional level self-assessment program. Each Division is also required to develop a self-assessment program that contains the elements described in this document.

  16. Recent geothermal reservoir engineering activities at Lawrence Berkeley Laboratory

    SciTech Connect

    Lippmann, M.J.; Bodvarsson, G.S.; Benson, S.M.; Pruess, K.

    1987-09-01

    This paper briefly describes the most recent activities in reservoir engineering for the geothermal group of Lawrence Berkeley Laboratory (LBL). The primary emphasis of the geothermal program of LBL is dedicated to reservoir engineering including theoretical investigations, the development and application of mathematical models, and field studies. The objectives of these activities are to develop and validate methods and instruments which will be utilized in the determination of the parameters of geothermal systems, and the identification and evaluation of the importance of the distinct processes which occur in reservoirs. The ultimate goal of the program is the development of state of the art technologies which characterize geothermal reservoirs and evaluate their productive capacity and longevity.

  17. The Lawrence Livermore National Laboratory Intelligent Actinide Analysis System

    SciTech Connect

    Buckley, W.M.; Carlson, J.B.; Koenig, Z.M.

    1993-07-01

    The authors have developed an Intelligent Actinide Analysis System (IAAS) for Materials Management to use in the Plutonium Facility at the Lawrence Livermore National Laboratory. The IAAS will measure isotopic ratios for plutonium and other actinides non-destructively by high-resolution gamma-ray spectrometry. This system will measure samples in a variety of matrices and containers. It will provide automated control of many aspects of the instrument that previously required manual intervention and/or control. The IAAS is a second-generation instrument, based on the authors` experience in fielding gamma isotopic systems, that is intended to advance non-destructive actinide analysis for nuclear safeguards in performance, automation, ease of use, adaptability, systems integration and extensibility to robotics. It uses a client-server distributed monitoring and control architecture. The IAAS uses MGA{sub 3} as the isotopic analysis code. The design of the IAAS reduces the need for operator intervention, operator training, and operator exposure.

  18. X-ray holography at Lawrence Livermore National Laboratory

    SciTech Connect

    Trebes, J.; Annese, C.; Birdsall, D.; Brase, J.; Gray, J.; Lane, S.; London, R.; Matthews, D.; Peters, D.; Pinkel, D.; Stone, G.; Rapp, D.; Rosen, M.; Weier, U.; Yorkey, T.

    1990-10-11

    The x-ray holography program at the Lawrence Livermore National Laboratory has two principal goals: (1) the development of x-ray diffraction techniques for DNA sequence analysis and (2) the development of x-ray laser holography for structural analysis of intact biological cells and organelles. DNA sequence analysis will be accomplished by applying x-ray diffraction techniques to determine the ensemble average of the sequence of labels along the individual elements of crystalline DNA. X-ray laser holographic imaging will be accomplished by applying three dimensional x-ray holography to elucidate the structure of few hundred angstrom objects such as 300 {Angstrom} chromatin fibers, nuclear pores and nucleic acid replication complexes in living cells. Existing laboratory x-ray lasers will be utilized to produce flash x-ray holograms of the biological structures.

  19. Lawrence Livermore National Laboratory (LLNL) Waste Minimization Program Plan

    SciTech Connect

    Heckman, R.A. ); Tang, W.R. )

    1989-08-04

    This Program Plan document describes the background of the Waste Minimization field at Lawrence Livermore National Laboratory (LLNL) and refers to the significant studies that have impacted on legislative efforts, both at the federal and state levels. A short history of formal LLNL waste minimization efforts is provided. Also included are general findings from analysis of work to date, with emphasis on source reduction findings. A short summary is provided on current regulations and probable future legislation which may impact on waste minimization methodology. The LLN Waste Minimization Program Plan is designed to be dynamic and flexible so as to meet current regulations, and yet is able to respond to an everchanging regulatory environment. 19 refs., 12 figs., 8 tabs.

  20. Lawrence Livermore National Laboratory laser-fusion program

    SciTech Connect

    Ahlstrom, H.G.

    1982-07-12

    The goals of the Laser-Fusion Program at Lawrence Livermore National Laboratory are to produce well-diagnosed, high-gain, laser-driven fusion explosions in the laboratory and to exploit this capability for both military applications and for civilian energy production. In the past year we have made significant progress both theoretically and experimentally in our understanding of the laser interaction with both directly coupled and radiation-driven implosion targets and their implosion dynamics. We have made significant developments in fabricating the target structures. Data from the target experiments are producing important near-term physics results. We have also continued to develop attractive reactor concepts which illustrate ICF's potential as an energy producer.

  1. The Computation Directorate at Lawrence Livermore National Laboratory

    SciTech Connect

    Cook, L

    2006-09-07

    The Computation Directorate at Lawrence Livermore National Laboratory has four major areas of work: (1) Programmatic Support -- Programs are areas which receive funding to develop solutions to problems or advance basic science in their areas (Stockpile Stewardship, Homeland Security, the Human Genome project). Computer scientists are 'matrixed' to these programs to provide computer science support. (2) Livermore Computer Center (LCC) -- Development, support and advanced planning for the large, massively parallel computers, networks and storage facilities used throughout the laboratory. (3) Research -- Computer scientists research advanced solutions for programmatic work and for external contracts and research new HPC hardware solutions. (4) Infrastructure -- Support for thousands of desktop computers and numerous LANs, labwide unclassified networks, computer security, computer-use policy.

  2. Global patterns and predictors of fish species richness in estuaries.

    PubMed

    Vasconcelos, Rita P; Henriques, Sofia; França, Susana; Pasquaud, Stéphanie; Cardoso, Inês; Laborde, Marina; Cabral, Henrique N

    2015-09-01

    1. Knowledge of global patterns of biodiversity and regulating variables is indispensable to develop predictive models. 2. The present study used predictive modelling approaches to investigate hypotheses that explain the variation in fish species richness between estuaries over a worldwide spatial extent. Ultimately, such models will allow assessment of future changes in ecosystem structure and function as a result of environmental changes. 3. A comprehensive worldwide data base was compiled of the fish assemblage composition and environmental characteristics of estuaries. Generalized Linear Models were used to quantify how variation in species richness among estuaries is related to historical events, energy dynamics and ecosystem characteristics, while controlling for sampling effects. 4. At the global extent, species richness differed among marine biogeographic realms and continents and increased with mean sea surface temperature, terrestrial net primary productivity and the stability of connectivity with a marine ecosystem (open vs. temporarily open estuaries). At a smaller extent (within a marine biogeographic realm or continent), other characteristics were also important in predicting variation in species richness, with species richness increasing with estuary area and continental shelf width. 5. The results suggest that species richness in an estuary is defined by predictors that are spatially hierarchical. Over the largest spatial extents, species richness is influenced by the broader distributions and habitat use patterns of marine and freshwater species that can colonize estuaries, which are in turn governed by history contingency, energy dynamics and productivity variables. Species richness is also influenced by more regional and local parameters that can further affect the process of community colonization in an estuary including the connectivity of the estuary with the adjacent marine habitat, and, over smaller spatial extents, the size of these habitats. In summary, patterns of species richness in estuaries across large spatial extents seem to reflect from global to local processes acting on community colonization. The importance of considering spatial extent, sampling effects and of combining history and contemporary environmental characteristics when exploring biodiversity is highlighted. PMID:25788236

  3. AN APPROACH TO DEVELOPING NUTRIENT CRITERIA FOR PACIFIC NORTHWEST ESTUARIES: A CASE STUDY OF YAQUINA ESTUARY, OREGON

    EPA Science Inventory

    NHEERL scientists have developed an approach that could be used by the State of Oregon for development of nutrient and other water quality criteria for the Yaquina Estuary, Oregon. The principle objective in setting protective criteria is to prevent future degradation of estuari...

  4. Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes

    USGS Publications Warehouse

    Takekawa, John Y.; Thorne, Karen M.; Buffington, Kevin J.; Spragens, Kyle A.; Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Overton, Cory T.; Casazza, Michael L.

    2013-01-01

    The International Panel on Climate Change has identified coastal ecosystems as areas that will be disproportionally affected by climate change. Current sea-level rise projections range widely with 0.57 to 1.9 meters increase in mea sea level by 2100. The expected accelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk, especially those in topographically low-gradient areas. We assessed marsh accretion and plant community state changes through 2100 at 12 tidal salt marshes around San Francisco Bay estuary with a sea-level rise response model. Detailed ground elevation, vegetation, and water level data were collected at all sites between 2008 and 2011 and used as model inputs. Sediment cores (taken by Callaway and others, 2012) at four sites around San Francisco Bay estuary were used to estimate accretion rates. A modification of the Callaway and others (1996) model, the Wetland Accretion Rate Model for Ecosystem Resilience (WARMER), was utilized to run sea-level rise response models for all sites. With a mean sea level rise of 1.24 m by 2100, WARMER projected that the vast majority, 95.8 percent (1,942 hectares), of marsh area in our study will lose marsh plant communities by 2100 and to transition to a relative elevation range consistent with mudflat habitat. Three marshes were projected to maintain marsh vegetation to 2100, but they only composed 4.2 percent (85 hectares) of the total marsh area surveyed.

  5. St. Vrain Creek

    St. Vrain Creek below Boulder Creek at Hwy 119 near Longmont, CO; Bob Brandle, Cory Stephens, Matt Nicotra, and Kevin Scofield measure discharge and install temporary streamgage replacing nearby damaged streamgage....

  6. Asymptomatic ST segment elevation.

    PubMed

    MacKenzie, Ross

    2004-01-01

    Asymptomatic ST segment elevation in a life insurance applicant's ECG raises several prognostically important possibilities such as myocardial infarction, pericarditis, Brugada syndrome and early repolarization. This ECG case study discusses the ECG features involved in the differential diagnosis. PMID:15104033

  7. "Lawrence v. Texas": Does This Mean Increased Privacy Rights for Gay and Lesbian Teachers?

    ERIC Educational Resources Information Center

    Eckes, Suzanne; McCarthy, Martha

    2004-01-01

    This article addresses the Supreme Court's 2003 decision in "Lawrence v. Texas" and its implications for the rights of gay and lesbian public school teachers. The authors provide a context by reviewing the teacher role-model theory, traditional standards used in dismissals for immoral conduct, and pre-"Lawrence" cases regarding public employees'…

  8. R.D. Lawrence, H.G. Wells, G.B. Shaw: a vignette.

    PubMed

    Jackson, J G

    1996-05-01

    Among the unpublished autobiographical notes of Dr R.D. Lawrence are numerous references to his contacts and friendship with the author H.G. Wells, who was to become the first President of the (British) Diabetic Association. Wells was responsible for Lawrence being called in for consultation by George Bernard Shaw, a meeting which was to have surprising consequences. PMID:8737021

  9. A revision of the endemic South African sac spider genus Lessertina Lawrence, 1942 (Araneae: Eutichuridae).

    PubMed

    Haddad, Charles R

    2014-01-01

    The endemic South African sac spider genus Lessertina Lawrence, 1942, previously known only from the type species (L. mutica Lawrence, 1942), is revised. Both sexes of L. mutica are redescribed and the species is recorded from the Eastern Cape, KwaZulu-Natal and Limpopo Provinces. A new species, L. capensis sp. nov., is described from the Eastern and Western Cape Provinces. PMID:25544208

  10. 78 FR 49254 - Approval of Subzone Status; GE Transportation; Lawrence Park Township and Grove City, Pennsylvania

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... Foreign-Trade Zones Board Approval of Subzone Status; GE Transportation; Lawrence Park Township and Grove..., requesting subzone status subject to the existing activation limit of FTZ 247, on behalf of GE Transportation, in Lawrence Park Township and Grove City, Pennsylvania. The applications were processed in...

  11. "Lawrence v. Texas": Does This Mean Increased Privacy Rights for Gay and Lesbian Teachers?

    ERIC Educational Resources Information Center

    Eckes, Suzanne; McCarthy, Martha

    2004-01-01

    This article addresses the Supreme Court's 2003 decision in "Lawrence v. Texas" and its implications for the rights of gay and lesbian public school teachers. The authors provide a context by reviewing the teacher role-model theory, traditional standards used in dismissals for immoral conduct, and pre-"Lawrence" cases regarding public employees'

  12. Synthesis and Modelling of Intermittent Estuaries

    NASA Astrophysics Data System (ADS)

    Kjerfve, Bjürn

    Port Hacking is a small subtropical estuary, relatively unpolluted despite its location only 30 km south of Sydney on Australia's Pacific coast. It was the site of a 5-year (1973-1978) multidisciplinary ecosystem project, focusing on the flow of carbon into, within, and out of the estuarine system. The ultimate goal of the project was the formulation and implementation of a predictive model of the carbon dynamics. However, this book, which summarizes the project, reports that the scientific team failed in its effort to reach the goal of a predictive model.

  13. Near coastal program plan for 1991: Estuaries

    SciTech Connect

    Not Available

    1990-11-01

    Environmental regulatory programs in the United States have been estimated to cost more than $70 billion annually. The Environmental Monitoring and Assessment Program (EMAP) is a nationwide initiative being implemented by EPA's Office of Research and Development (ORD). It was developed in response to the demand for information on the condition of the nation's ecological resources. The goal of EMAP is to assess and document the status and trends in the condition of the nation's forests, wetlands, estuaries, coastal waters, lakes, rivers, and streams, Great Lakes, agricultural lands, and arid lands on an integrated and continuing basis.

  14. Magnitude and extent of sediment toxicity in selected estuaries of South Carolina and Georgia. Technical memo

    SciTech Connect

    Long, E.R.; Scott, G.I.; Kucklick, J.; Fulton, M.; Thompson, B.

    1998-04-01

    Surficial sediment samples were collected from 162 locations within five estuaries -- Charleston Harbor, Winyah Bay, Leadenwah Creek, Savannah River, and St. Simons Sound -- in coastal South Carolina and Georgia in a survey of sediment toxicity performed in 1993 and 1994. All samples were tested for toxicity with a battery of complimentary laboratory bioassays. The laboratory bioassays consisted of amphipod survival tests in solid-phase sediments, microbial bioluminescence (Microtox{trademark}) tests of organic solvent extracts, and sea urchin fertilization and embryo development tests of porewaters. Some samples also were tested in copepod reproduction and cytochrome P-450 RGS bioassays. Chemical analyses for a suite of trace metals, organic compounds, and sedimentological factors were performed with portions of most samples.

  15. Sex alteration in soft-shell clams (Mya arenaria) in an intertidal zone of the Saint Lawrence river (Quebec, Canada).

    PubMed

    Gagné, F; Blaise, C; Pellerin, J; Pelletier, E; Douville, M; Gauthier-Clerc, S; Viglino, L

    2003-02-01

    The purpose of this study was to verify whether any changes in sex ratio might occur in soft-shell clams (Mya arenaria) located in an intertidal harbor zone located at the mouth of the Saguenay Fjord in the Saint Lawrence estuary (Baie Sainte-Catherine (BSC), Québec, Canada) likely to be contaminated by organotin compounds. Bivalves were harvested at the BSC harbor site and from two reference sites. Condition index (weight to length ratio), gonado-somatic index, sex ratio, vitellin-like proteins, organotin concentrations in gonad tissue, maturation stages of the gonads, the number of estradiol-17beta binding sites and the capacity of female gonad extracts to produce estradiol-17beta were determined in collected animals. Results showed that sex ratio in clams was significantly skewed toward males. Moreover, the condition and gonad-somatic indices, vitellin-like proteins in female gonads and the capacity of female gonads to produce estradiol-17beta were significantly reduced at the harbor site with respect to the reference sites. Maturation status of male gonads was clearly delayed at the harbor site. Additionally, gonad tissue contained tributyltin (TBT) at an average level of 109+/-18 ngSn/gdry wt. at the harbor site while organotins were not detected from the reference sites. Finally, female gonads had a higher number of unoccupied estradiol binding sites at the harbor site indicating low levels of this steroid in this tissue. Overall, this paper is first to report that clams collected in the vicinity of a TBT contaminated harbor are subject to masculinizing effects which seems to be consistent with biological effects that organotins are known to exert toward some other marine invertebrates. PMID:12600678

  16. The biology of Solea bleekeri (Teleostei) in Lake St Lucia on the southeast coast of Africa

    NASA Astrophysics Data System (ADS)

    Cyrus, D. P.

    Several aspects of the biology of Solea bleekeri in Lake St Lucia were investigated, these included occurrence, distribution, reproduction and recruitment, food and feeding, size frequency distribution and the role of estuaries in the species' life cycle. Solea bleekeri was found to occur throughout the system in muddy turbid areas and was largely absent from the eastern shores of the lake where clear water sandy substrata occur. The preferred diet of the species was bivalve siphon tips of the species Solon cylindraceus, when these were in abundant supply. However, when numbers of large (length > 20 mm) specimens were not available then S. bleekeri fed on whatever prey was available in or near the substratum. Analysis of stomach contents under the latter conditions showed that food consumption reflected the composition of the benthos. Large numbers of S. bleekeri spend their entire post-larval and juvenile phases as well as the greater part of their adult life within estuaries. Evidence is presented to support the idea that S. bleekeri breeds in certain areas of the lake and that spawning takes place between September and November. The current data suggest that there may be two populations in St Lucia: one migrates from the system to spawn at sea during winter along with the other marine fish species which utilize estuaries as nursery areas, while the other population breeds within the system. Alternatively there may simply be a single population which normally breeds at sea, but which may breed within the system when conditions are suitable. Recruitment of S. bleekeri into the St Lucia estuarine system takes place from the muddy offshore marine banks and possibly from within the system as well. Solea bleekeri appears not to be totally dependent on estuaries for the completion of its life cycle. The advantages of utilizing these systems for their development relate to the shallow, calm, turbid food-rich areas which estuaries offer. The fact that breeding takes place within St Lucia means that adults and juveniles are present in varying numbers throughout the year.

  17. Acoustical Characterization of the Columbia River Estuary

    NASA Astrophysics Data System (ADS)

    Reeder, D. B.

    2014-12-01

    Investigations of near-shore and in-shore environments have, rightly, focused on geological, thermodynamic and hydrodynamic parameters. A complementary acoustical characterization of the estuarine environment provides another layer of information to facilitate a more complete understanding of the physical environment. Relatively few acoustical studies have been carried out in rivers, estuaries or other energetic environments; nearly all acoustical work in such environments has been done at high acoustic frequencies—in the 10's and 100's of kHz. To this end, within the context of a larger hydrodynamic field experiment (RIVET II), a small acoustic field experiment was carried out in the Columbia River Estuary (CRE), the acoustic objective of which was to characterize the acoustic environment in the CRE in terms of ambient noise field statistics and acoustic propagation characteristics at low-to-mid-frequencies. Acoustically, the CRE salt wedge consists of two isospeed layers separated by a thin, three-dimensional high-gradient layer. Results demonstrate that (1) this stratification supports ducting of low-angle acoustic energy in the upper layer and the creation of an acoustic shadow zone in the lower layer; (2) the spatiotemporal dynamics of the salt wedge structure during the very energetic flood and ebb tides induce significant variability in the acoustic environment, as well as significant flow noise across the acoustic transducer; and (3) this flow noise correlates to current velocity and complicates acoustical observations at low frequencies.

  18. Scavenging Rate Ecoassay: A Potential Indicator of Estuary Condition

    PubMed Central

    Porter, Augustine G.; Scanes, Peter R.

    2015-01-01

    Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress. PMID:26024225

  19. Geographic signatures of North American West Coast estuaries

    USGS Publications Warehouse

    Emmett, Robert; Llansó, Roberto; Newton, Jan; Thom, Ron; Hornberger, Michelle; Morgan, Cheryl; Levings, Colin; Copping, Andrea; Fishman, Paul

    2000-01-01

    West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources.

  20. 75 FR 8428 - The Indiana Rail Road Company-Abandonment Exemption-in Martin and Lawrence Counties, IN; CSX...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... Transportation, Inc.--Discontinuance of Service Exemption--in Clark, Floyd, Lawrence, Orange, and Washington..., Floyd, Lawrence, Orange, and Washington Counties, IN, a petition for exemption was filed by...

  1. St. Louis, Missouri

    NASA Technical Reports Server (NTRS)

    2007-01-01

    St. Louis is tucked in a bend of the Mississippi River, just south of the point at which the Illinois River joins the larger Mississippi, and where the Missouri River flows in from the west. Drainage patterns to the east, on the Illinois side, are highlighted with green vegetation. Meandering rivers in the verdant Ozark Plateau appear to the south and west.

    This true-color view from NASA's Multi-angle Imaging SpectroRadiometer (MISR) was taken with the instrument's downward looking (nadir) camera on October 15, 2005. The urban areas of greater St. Louis show up as grey-white, including nearby Kirkwood, Webster Groves, Clayton, University City, Ferguson, St. Ann, St. Charles, and East St. Louis. The region is home to nearly three million people.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. JPL is a division of the California Institute of Technology.

  2. Sediment Transport Processes In River Dominated Sub-Tropical Estuaries

    NASA Astrophysics Data System (ADS)

    DAquino, Carla; Schettini, Carlos

    2014-05-01

    The objective of this study is to present a comparative assessment of the largest three river dominated estuaries in the southern coast of the state of Santa Catarina, Brazil (Tubarão, Araranguá and Mampituba estuaries). The study was focused on mechanisms of transport of suspended sediments influenced by its morphologic and hydrodynamics characteristics. As shown in D'Aquino et al (2011), these estuaries share common attributes (climate and tides) and follow the basic conceptual model of fine sediment transport (presented by Toldo & Schettini (2006). However, each one has its own particularities regarding the geographical setting, land use, hypsometry, outfall, etc. The methodology used to the field measurements was the same for all estuaries, aiming at measuring the currents, water level, salinity, temperature and turbidity near the outfall for at least two complete tidal cycles (~25 hours). All the campaigns were carried on under syzygya tide conditions. During the sample collecting period, a longitudinal profile was conducted in each estuary, through acquisitions of salinity and temperature of the water column in every kilometer. In the Tubarão and Araranguá rivers estuaries, the concentration of suspended particulate matter (SPM) is mostly influenced by the periods of incoming tide, flood currents. In the Mampituba river estuary, the flocculation process was observed during the encounter of fresh and salt water in every tide entrance. It was possible to observe that the Araranguá river estuary, in what concerns the bottom SPM, responds to the variation of salinity and currents along the bottom. The Tubarão estuary presents a relation between the salinity and the bottom currents. In the Mampituba estuary no relevant correlation was found between the SPM, the salinity, and the bottom currents. Those aspects demonstrate that even sharing some characteristics there are significant differences among these estuaries. In addition, as a result of the comparative study, an analytical model was proposed that correlates the fluvial discharge, salt wedge, and SPM. This model might represent a tool to encourage discussions and help the scientific exploration of the estuaries in the south of Santa Catarina.

  3. Influence of intermittent estuary outflow on coastal sediments of adjacent sandy beaches

    NASA Astrophysics Data System (ADS)

    McKenzie, Jessica L.; Quinn, Gerry P.; Matthews, Ty G.; Barton, Jan; Bellgrove, Alecia

    2011-03-01

    Outflows from estuaries potentially contribute to the productivity of adjacent coastal waters, although most previous work has been on estuaries with considerable river discharge. We investigated the influence of estuary outflow on aspects of coastal sediments adjacent to two seasonally intermittent estuaries, the Curdies and Anglesea Rivers, in southwest Victoria, Australia. For each estuary, we measured sediment organic matter, microphytobenthic chlorophyll a and microbial utilization of carbon sources at three locations associated with each estuary: (1) inside estuary mouth, (2) estuary swash and (3) control swash (an open beach distant from any estuarine influences). Sampling occurred one week before and at one and nine weeks after both an artificial mouth opening and a separate natural flood at both estuaries. Significant temporal changes were detected for all three variables at the estuary mouth and estuary swash but the direction of change was inconsistent across the two estuaries and between the artificial mouth opening and natural flood. Organic matter in both estuaries showed no difference after the artificial mouth openings. Only Anglesea showed an increase in organic matter in the estuary mouth and estuary swash after the floods. Microphytobenthic chlorophyll a concentrations were highest when the estuary mouths were closed. Concentrations decreased at all locations at Curdies after the mouth was artificially opened. The estuary mouth at Anglesea sustained high chlorophyll concentrations and the estuary swash increased one week post artificial opening. The flood event resulted in an increase in chlorophyll a at the estuary mouth and swash at both estuaries, one week post flood. At Curdies, the microbial utilization of different carbon sources changed after both mouth events; estuary mouth and estuary swash showed similar patterns at one and nine weeks post opening. At Anglesea, the bacteria utilized different carbon sources between locations and the only significant interaction between location and time was post flood with change in carbon sources utilized by bacteria in the estuary mouth and estuary swash for one and nine weeks post flood. The southern coastline of Australia is characterized by estuaries with small catchments. This study highlights the spatial and temporal variability in the effects of the output of relatively small, intermittent estuaries on coastal sediment of adjacent beaches, particularly during prolonged periods of drought.

  4. Seasonal Patterns in the Fish and Crustacean Community of a Turbid Temperate Estuary (Zeeschelde Estuary, Belgium)

    NASA Astrophysics Data System (ADS)

    Maes, J.; Taillieu, A.; Van Damme, P. A.; Cottenie, K.; Ollevier, F.

    1998-08-01

    Fish and crustaceans were sampled for 1 year in the upper reaches of a temperate estuary characterized by high turbidity and a tidal range of up to 5 m. Samples were taken in the cooling-water circuit of the Doel Nuclear Power station (Zeeschelde, Belgium). Between July 1994 and June 1995, 55 fish species, two shrimp species and four crab species were recorded. The fish community was composed of 36 marine species, 16 freshwater species and three diadromous species. Shrimps, Gobiidae and Clupeidae dominated the samples both in numbers and biomass. An exceptionally clear seasonal succession was observed in the species composition. It is argued that young fish and crustaceans use the highly turbid Zeeschelde Estuary as a refuge from predators.

  5. LLNL (Lawrence Livermore National Laboratory) research on cold fusion

    SciTech Connect

    Thomassen, K I; Holzrichter, J F

    1989-09-14

    With the appearance of reports on Cold Fusion,'' scientists at the Lawrence Livermore National Laboratory (LLNL) began a series of increasingly sophisticated experiments and calculations to explain these phenomena. These experiments can be categorized as follows: (a) simple experiments to replicate the Utah results, (b) more sophisticated experiments to place lower bounds on the generation of heat and production of nuclear products, (c) a collaboration with Texas A M University to analyze electrodes and electrolytes for fusion by-products in a cell producing 10% excess heat (we found no by-products), and (d) attempts to replicate the Frascati experiment that first found neutron bursts when high-pressure deuterium gas in a cylinder with Ti chips was temperature-cycled. We failed in categories (a) and (b) to replicate either the Pons/Fleischmann or the Jones phenomena. We have seen phenomena similar to the Frascati results, (d) but these low-level burst signals may not be coming from neutrons generated in the Ti chips. Summaries of our experiments are described in Section II, as is a theoretical effort based on cosmic ray muons to describe low-level neutron production. Details of the experimental groups' work are contained in the six appendices. At LLNL, independent teams were spontaneously formed in response to the early announcements on cold fusion. This report's format follows this organization.

  6. Tiger Team assessment of the Lawrence Berkeley Laboratory, Washington, DC

    SciTech Connect

    Not Available

    1991-02-01

    This report documents the results of the Department of Energy's (DOE's) Tiger Team Assessment of the Lawrence Berkeley Laboratory (LBL) conducted from January 14 through February 15, 1991. The purpose of the assessment was to provide the Secretary of Energy with the status of environment, safety, and health (ES H) programs at LBL. The Tiger Team concluded that curtailment of cessation of any operations at LBL is not warranted. However, the number and breadth of findings and concerns from this assessment reflect a serious condition at this site. In spite of its late start, LBL has recently made progress in increasing ES H awareness at all staff levels and in identifying ES H deficiencies. Corrective action plans are inadequate, however, many compensatory actions are underway. Also, LBL does not have the technical expertise or training programs nor the tracking and followup to effectively direct and control sitewide guidance and oversight by DOE of ES H activities at LBL. As a result of these deficiencies, the Tiger Team has reservations about LBL's ability to implement effective actions in a timely manner and, thereby, achieve excellence in their ES H program. 4 figs., 24 tabs.

  7. Lawrence Livermore National Laboratory Working Reference Material Production Pla

    SciTech Connect

    Amy Wong; Denise Thronas; Robert Marshall

    1998-11-04

    This Lawrence Livermore National Laboratory (LLNL) Working Reference Material Production Plan was written for LLNL by the Los Alamos National Laboratory to address key elements of producing seven Pu-diatomaceous earth NDA Working Reference Materials (WRMS). These WRMS contain low burnup Pu ranging in mass from 0.1 grams to 68 grams. The composite Pu mass of the seven WRMS was designed to approximate the maximum TRU allowable loading of 200 grams Pu. This document serves two purposes: first, it defines all the operations required to meet the LLNL Statement of Work quality objectives, and second, it provides a record of the production and certification of the WRMS. Guidance provided in ASTM Standard Guide C1128-89 was used to ensure that this Plan addressed all the required elements for producing and certifying Working Reference Materials. The Production Plan was written to provide a general description of the processes, steps, files, quality control, and certification measures that were taken to produce the WRMS. The Plan identifies the files where detailed procedures, data, quality control, and certification documentation and forms are retained. The Production Plan is organized into three parts: a) an initial section describing the preparation and characterization of the Pu02 and diatomaceous earth materials, b) middle sections describing the loading, encapsulation, and measurement on the encapsulated WRMS, and c) final sections describing the calculations of the Pu, Am, and alpha activity for the WRMS and the uncertainties associated with these quantities.

  8. STS-86 crew members (Parazynski, Wolf, Lawrence) in slidewire basket

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-86 Mission Specialists Scott E. Parazynski, at left, David A. Wolf, and Wendy B. Lawrence, at right, participate in emergency egress training at Launch Pad 39A as part of Terminal Countdown Demonstration Test (TCDT) activities. They are the three U.S. astronauts who will serve as mission specialists during the planned 10-day flight to the Russian Space Station Mir. Also serving as mission specialists will be Vladimir Georgievich Titov of the Russian Space Agency and Jean-Loup J.M. Chretien of the French Space Agency, CNES. STS-86 will be the seventh docking of the Space Shuttle with the Mir. During the docking, Wolf will transfer to the orbiting Russian station and become a member of the Mir 24 crew, replacing U.S. astronaut C. Michael Foale, who has been on the Mir since the last docking mission, STS-84, in May. Launch of Mission STS-86 aboard the Space Shuttle Atlantis is targeted for Sept. 25.

  9. Environmental Survey preliminary report, Lawrence Livermore National Laboratory, Livermore, California

    SciTech Connect

    Not Available

    1987-12-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the Department of Energy (DOE) Lawrence Livermore National Laboratory (LLNL), conducted December 1 through 19, 1986. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with LLNL. The Survey covers all environmental media all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations performed at LLNL, and interviews with site personnel. A Sampling and Analysis Plan was developed to assist in further assessing certain of the environmental problems identified during performance of on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory. When completed, the results will be incorporated into the LLNL Environmental Survey Interim Report. The Interim Report will reflect the final determinations of the LLNL Survey. 70 refs., 58 figs., 52 tabs.,

  10. Environmental Survey preliminary report, Lawrence Berkeley Laboratory, Berkeley, California

    SciTech Connect

    Not Available

    1988-07-01

    The purpose of this report is to present the preliminary findings made during the Environmental Survey, February 22--29, 1988, at the US Department of Energy (DOE) Lawrence Berkeley Laboratory (LBL) in Berkeley, California. The University of California operates the LBL facility for DOE. The LBL Survey is part of the larger DOE-wide Environmental Survey announced by Secretary John S. Herrington on September 18, 1985. The purpose of this effort is to identify, via no fault'' baseline Surveys, existing environmental problems and areas of environmental risk at DOE facilities, and to rank them on a DOE wide basis. This ranking will enable DOE to more effectively establish priorities for addressing environmental problems and allocate the resources necessary to correct them. Because the Survey is no fault'' and is not an audit,'' it is not designed to identify specific isolated incidents of noncompliance or to analyze environmental management practices. Such incidents and/or management practices will, however, be used in the Survey as a means of identifying existing and potential environmental problems. The LBL Survey was conducted by a multidisciplinary team of technical specialists headed and managed by a Team Leader and Assistant Team Leader from DOE's Office of Environmental Audit. A complete list of the LBL Survey participants and their affiliations is provided in Appendix A. 80 refs., 27 figs., 37 tabs.

  11. Reuse of waste cutting sand at Lawrence Livermore National Laboratory

    SciTech Connect

    Mathews, S., LLNL

    1998-02-25

    Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchases by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in ac concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved.

  12. Lawrence Berkeley Laboratory, FY 1993 Site Development Plan

    SciTech Connect

    Not Available

    1993-04-01

    The Lawrence Berkeley Laboratory (LBL) 1993 Site Development Plan (SDP) provides analysis and policy guidance for the effective use and orderly development of land and facilities at the LBL main site. The SDP directly supports LBL`s role as a multiprogram national laboratory operated by the University of California (UC) for the Department of Energy (DOE). It is a concise policy document, prepared in compliance with DOE Order 4320.1 B, and is coupled to the 1993 Laboratory Integrated Facilities Plan (LIFP). It also serves as the current DOE framework for the implementation of the 1987 Long Range Development Plan (LRDP) approved by the Regents of the University of California. The SDP is updated annually, with periodic major revisions consistent with DOE policy and approved plans of the Regents. The plan is reviewed and approved by the DOE San Francisco Field Office. The specific purposes of the SDP are to: Summarize the mission and community setting of the Laboratory; Describe program trends and projections and future resource requirements; Describe site planning goals and future facilities and land uses; and Describe site planning issues and potential infrastructure replacement solutions. The SDP concisely expresses the policies for future development based on planning concepts, the anticipated needs of research programs, and site potential and constraints. The 1993 LIFP and other planning data provide detailed support for the plans identified in this document.

  13. STS-114 Crew Interviews: 1. Eileen Collins 2. Wendy Lawrence

    NASA Technical Reports Server (NTRS)

    2005-01-01

    1) STS-114 Commander Eileen Collins emphasized her love for teaching, respect for teachers, and her plan to go back to teaching again someday. Her solid background in Math and Science, focus on her interests, with great support from her family, and great training and support during her career with the Air Force gave her confidence in pursuing her dream to become an astronaut. Commander Collins shares her thoughts on the Columbia, details the various flight operations and crew tasks that will take place during the mission and the importance of Shuttle missions to the International Space Station and space exploration. 2) STS-114 Mission Specialist Wendy Lawrence first dreamed of becoming an astronaut when she watched Neil Armstrong walk on the moon from their black and white TV set. She majored in Engineering and became a Navy pilot. She shares her thoughts on the Columbia, details her major role as the crew in charge of all the transfer operations; getting the MPLM unpacked and repacked; and the importance of Shuttle missions to the International Space Station and space exploration.

  14. Stormwater metal loading to a well-mixed/stratified estuary (Sydney Estuary, Australia) and management implications.

    PubMed

    Birch, Gavin F; Rochford, L

    2010-10-01

    Stormwater modelling indicated an average annual discharge from Sydney estuary catchment of 215,300 mL and loadings of 0.8, 0.5, 1.7, 3.2, 1.1, 3.6 and 17.7 tonnes for As, Cd, Cr, Cu, Ni, Pb and Zn, respectively. Priority for remediation should be given to creeks with high-metal loads in the upper and central estuary, as well as discharging to the western shores of Middle Harbour. Managerial strategies need to target dissolved and particulate metal phases to ensure effective remediation. The proportion of metals discharged under low- (<5 mm rainfall/day), medium- (>5 to <50 mm/day) and high-flow conditions (>50 mm/day) was approximately 10%, 60% and 30% of total loading, respectively. Under high-flow conditions the estuary becomes stratified and most metals are exported to the sea, whereas metals discharged during low-flow may be remediated by infiltration. Effective remediation will depend on the extent to which 'first-flush' metals associated with medium-flow conditions can be remediated. PMID:19859822

  15. 46 CFR 401.405 - Basic rates and charges on the St. Lawrence River and Lake Ontario.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Lake Ontario. 401.405 Section 401.405 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE REGULATIONS Rates, Charges, and Conditions for Pilotage Services... affecting § 401.405, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  16. 46 CFR 401.405 - Basic rates and charges on the St. Lawrence River and Lake Ontario.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Lake Ontario. 401.405 Section 401.405 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE REGULATIONS Rates, Charges, and Conditions for Pilotage Services... affecting § 401.405, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  17. Wadter Resources Data Ohio: Water year 1994. Volume 2, St. Lawrence River Basin and Statewide Project Data

    SciTech Connect

    1994-12-31

    The Water Resources Division of the US Geological Survey (USGS), in cooperation with State agencies, obtains a large amount of data each water year (a water year is the 12-month period from October 1 through September 30 and is identified by the calendar year in which it ends) pertaining to the water resources of Ohio. These data, accumulated during many years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the USGS, they are published annually in this report series entitled ``Water Resources Data--Ohio.`` This report (in two volumes) includes records on surface water and ground water in the State. Specifically, it contains: (1) Discharge records for streamflow-gaging stations, miscellaneous sites, and crest-stage stations; (2) stage and content records for streams, lakes, and reservoirs; (3) water-quality data for streamflow-gaging stations, wells, synaptic sites, and partial-record sites; and (4) water-level data for observation wells. Locations of lake- and streamflow-gaging stations, water-quality stations, and observation wells for which data are presented in this volume are shown in figures ga through 8b. The data in this report represent that part of the National Water Data System collected by the USGS and cooperating State and Federal agencies in Ohio. This series of annual reports for Ohio began with the 1961 water year with a report that contained only data relating to the quantities of surface water. For the 1964 water year, a similar report was introduced that contained only data relating to water quality. Beginning with the 1975 water year, the report was changed to present (in two to three volumes) data on quantities of surface water, quality of surface and ground water, and ground-water levels.

  18. GENETIC ANALYSIS OF THE CHINESE MITTEN CRAB (ERIOCHEIR SINENSIS) INTRODUCED TO THE NORTH AMERICAN GREAT LAKES AND ST. LAWRENCE SEAWAY

    EPA Science Inventory

    The Chinese mitten crab (Eriocheir sinensis) is a globally invasive organism, with established non-native populations in Europe and California, USA. Since 1965, there have been sixteen confirmed catches of E. sinensis in the North American Great Lakes and their associated waterw...

  19. Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach Using Expert Judgment, Volume I: Results for the San Francisco Estuary Partnership (Final Report)

    EPA Science Inventory

    Cover of the San Francisco <span class=Estuary Partnership Climate Ready Estuaries Program Final Report"> As part of the Climate Ready Estuaries (CRE) pr...

  20. Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach Using Expert Judgment, Volume I: Results for the San Francisco Estuary Partnership (Final Report)

    EPA Science Inventory

    Cover of the San Francisco <span class=Estuary Partnership Climate Ready Estuaries Program Final Report"> As part of the Climate Ready Estuaries (CRE) pr...

  1. Use of the USEPA Estuary Nitrogen Model to Estimate Concentrations of Total Nitrogen in Estuaries Using Loads Calculated by Watershed Models and Monitoring Data

    EPA Science Inventory

    We use USEPA’s Estuary Nitrogen Model (ENM) to calculate annual average concentrations of total nitrogen (TN) in ten estuaries or sub-estuaries along the Atlantic coast from New Hampshire to Florida. These include a variety of systems, ranging from strongly-flushed bays to weakly...

  2. Beyond Lawrence v. Texas: crafting a fundamental right to sexual privacy.

    PubMed

    Fasullo, Kristin

    2009-05-01

    After the watershed 2003 U.S. Supreme Court decision Lawrence v.Texas, courts are faced with the daunting task of navigating the bounds of sexual privacy in light of Lawrence's sweeping language and unconventional structure. This Note focuses on the specific issue of state governments regulating sexual device distribution. Evaluating the substantive due process rights of sexual device retailers and users, this Note ultimately argues that the privacy interest identified in Lawrence is sufficiently broad to protect intimate decisions to engage in adult consensual sexual behavior, including the liberty to sell, purchase, and use a sexual device. PMID:19618552

  3. A PROBABILISTIC SURVEY OF SEDIMENT TOXICITY IN WEST COAST ESTUARIES

    EPA Science Inventory

    A probabalistic survey of coastal condition assessment was conducted in 1999 by participants in US EPA's Environmental Monitoring and Assessment Program (EMAP). The survey targeted estuaries along the outer coasts of Washington, Oregon and California, including the lower Columbi...

  4. BACTERIOPLANKTON DYNAMICS IN A SUBTROPICAL ESTUARY: EVIDENCE FOR SUBSTRATE LIMITATION

    EPA Science Inventory

    Bacterioplankton abundance and metabolic characteristics were measured along a transect in Pensacola Bay, Florida, USA, to examine the factors that control microbial water column processes in this subtropical estuary. The microbial measures included 3 H-L-leucine incorporation, e...

  5. DOWNSTREAM MIGRATION OF SALMONID SMOLTS IN OREGON RIVERS AND ESTUARIES

    EPA Science Inventory

    Migratory fish passage is an important designated use for many Oregon estuaries. Acoustic transmitters were implanted in coho smolts in 2004 and 2006 to evaluate how estuarine habitat, and habitat loss, might affect population health. Acoustic receivers that identified individu...

  6. NEKTON-HABITAT ASSOCIATIONS IN A PACIFIC NORTHWEST (USA) ESTUARY

    EPA Science Inventory

    Nekton−habitat associations were determined in Yaquina Bay, Oregon, United States, using a stratified-by-habitat, random, estuary-wide sampling design. Three habitats (intertidal eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], and ghost shrimp [Neotrypaea californie...

  7. SPATIAL DISTRIBUTIONS OF BURROWING SHRIMP POPULATIONS IN TWO OREGON ESTUARIES

    EPA Science Inventory

    Thalassinid burrowing shrimp (Neotrypaea californiensis and Upogebia pugettensis) inhabit large expanses of Pacific estuarine tide flats, from British Columbia to Baja California. The spatial distribution of shrimp populations within estuaries has rarely been quantified because ...

  8. MODIS water quality algorithms for northwest Florida estuaries

    EPA Science Inventory

    Synoptic and frequent monitoring of water quality parameters from satellite is useful for determining the health of aquatic ecosystems and development of effective management strategies. Northwest Florida estuaries are classified as optically-complex, or waters influenced by chlo...

  9. CASCO BAY ESTUARY PROJECT TRIENNIAL IMPLEMENTATION REVIEW MARCH, 2004

    EPA Science Inventory

    The Casco Bay Estuary Project has seven primary goals/priorities which include: minimize pollutant loading from stormwater; open and protect shellfish beds; protect and restore habitat; reduce toxic pollution; promote responsible stewardship; sustain and promote the continued eff...

  10. SAN JUAN BAY ESTUARY PROGRAM IMPLEMENTATION REVIEW ATTACHMENTS

    EPA Science Inventory

    A compilation of attachments referenced in the San Juan Bay Estuary Program Implementation Review (2004). Materials include, entity reports, water and sediment quality action plans, progress reports, correspondence with local municipalities and Puerto Rican governmental agencies,...

  11. HIGH CYANOBACTERIAL ABUNDANCE IN GULF OF MEXICO ESTUARIES

    EPA Science Inventory

    Aquatic phytoplankton comprise a wide variety of taxa spanning more than 2 orders of magnitude in size, yet studies of estuarine phytoplankton often overlook the picoplankton, particularly chroococcoid cyanobacteria (c.f. Synechocococcus). Three Gulf of Mexico estuaries (Apalachi...

  12. OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY

    EPA Science Inventory

    EXECUTIVE SUMMARY: OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY Rates of oxygen consumption and nutrient regeneration were measured annually throughout the Peconic Estuarine System. Sediment and water column oxygen uptake were measured to determine the potential...

  13. Hydrology of major estuaries and sounds of North Carolina

    USGS Publications Warehouse

    Giese, G.L.; Wilder, Hugh B.; Parker, Garald G., Jr.

    1979-01-01

    Knowledge of the basic hydrology of North Carolina 's major estuaries and sounds is necessary to help solve hydrology-related estuarine problems which include contamination of some estuaries with municipal and industrial wastes and drainage from adjacent intensively-farmed areas, nuisance-level algal blooms, excessive shoaling in some navigation channels, saltwater intrusion into usually fresh estuarine reaches, too-high or too-low salinities in nursery areas for various estuarine species, and flood damages due to hurricanes. Saltwater intrusion occurs from time to time in all major estuaries in North Carolina except the Roanoke River, where releases from Roanoke Rapids Lake and other reservoirs during otherwise low-flow periods effectively block saline water from the estuary. (Woodard-USGS)

  14. Evaluating Causes of Ecological Impairments in the Estuaries of Ukraine

    EPA Science Inventory

    Ukrainian estuaries have not undergone a systematic evaluation of the causes of ecological impairments caused by anthropogenic contamination. The objective of this evaluation is to use recently developed diagnostic tools to determine the causes of benthic ecological impairments. ...

  15. Assessing the impact of human activities on British Columbia's estuaries.

    PubMed

    Robb, Carolyn K

    2014-01-01

    The world's marine and coastal ecosystems are under threat and single-sector management efforts have failed to address those threats. Scientific consensus suggests that management should evolve to focus on ecosystems and their human, ecological, and physical components. Estuaries are recognized globally as one of the world's most productive and most threatened ecosystems and many estuarine areas in British Columbia (BC) have been lost or degraded. To help prioritize activities and areas for regional management efforts, spatial information on human activities that adversely affect BC's estuaries was compiled. Using statistical analyses, estuaries were assigned to groups facing related threats that could benefit from similar management. The results show that estuaries in the most populated marine ecosections have the highest biological importance but also the highest impacts and the lowest levels of protection. This research is timely, as it will inform ongoing marine planning, land acquisition, and stewardship efforts in BC. PMID:24937486

  16. MAPPING BURROWING SHRIMP AND SEAGRASS IN YAQUINA ESTUARY

    EPA Science Inventory

    Burrowing shrimp and seagrasses create extensive intertidal and shallow subtidal habitats within Pacific NW estuaries. Maps of their populations are useful to inform estuarine managers of locations that deserve special consideration for conservation, and to inform oyster farmers...

  17. LOUISIANIAN PROVINCE DEMONSTRATION REPORT - EMAP-ESTUARIES: 1991

    EPA Science Inventory

    This report summarizes the Louisianian Demonstration Project conducted by the Estuaries Resource Group of the Environmental Monitoring and Assessment Program (EMAP), a national program initiated by EPA to integrate efforts of governmental agencies in evaluations of status and tre...

  18. Landscape Thresholds and the Condition of Northeastern Estuaries

    EPA Science Inventory

    Anthropogenic impacts to northeastern estuaries have been well documented and many researchers have quantified the associations between broad scale human land uses in contributing landscapes and impacted estuarine condition. However, associations alone are not adequate for ident...

  19. FRESHWATER INFLOWS: WATER FOR HEALTHY ESTUARIES CONFERENCE (MX96476507

    EPA Science Inventory

    The grantee will hold an interstate workshop on Freshwater Inflow issues in the Gulf of Mexico coastal region. The conference will identify water management questions to be addressed regarding providing freshwater inflows to estuaries, update participants on the current scientif...

  20. View of looking southeast of 2313 31st St. hipped ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of looking southeast of 2313 31st St. - hipped roof house with engaged porch located in Shawmut Mill village section of Valley - 2313 Thirty-first Street (House), 2313 Thirty-first Street, Valley, Chambers County, AL