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1

Acidification of Lower St. Lawrence Estuary Bottom Waters  

Microsoft Academic Search

Accumulation of metabolic CO2 can acidify marine waters above and beyond the ongoing acidification of the ocean by anthropogenic CO2. The impact of respiration on carbonate chemistry and pH is most acute in hypoxic and anoxic basins, where metabolic CO2 accumulates to high concentrations. The bottom waters of the Lower St. Lawrence Estuary (LSLE), where persistently severe hypoxia has developed

Alfonso Mucci; Michel Starr; Denis Gilbert; Bjorn Sundby

2011-01-01

2

Recent transfer of coastal sediments to the Laurentian Channel, Lower St. Lawrence Estuary (Eastern Canada),  

E-print Network

to study the activity of submarine canyons and fans near the city of Les Escou- mins, on the North Shore. 2008). The North Shore of the St. Lawrence Estuary and Gulf (Fig. 1) is characterized by significant

Long, Bernard

3

Anguilla rostrata glass eel migration and recruitment in the estuary and Gulf of St Lawrence.  

PubMed

This study describes catches of Anguilla rostrata glass eels and associated oceanographic conditions in the St Lawrence Estuary and Gulf. Ichthyoplankton survey data suggest that they enter the Gulf primarily in May, migrate at the surface at night, and disperse broadly once they have passed Cabot Strait. They arrive in estuaries beginning at about mid-June and through the month of July. Migration extends west up to Québec City, in the freshwater zone of the St Lawrence Estuary, 1000 km west of Cabot Strait. Anguilla rostrata glass eels travel between Cabot Strait and receiving estuaries at a straight-line ground speed of c. 10-15 km day(-1). Catches of fish per unit effort in estuaries in the St Lawrence system are much lower than those reported for the Atlantic coast of Canada. Low abundance of A. rostrata glass eels in the St Lawrence system may be due to cold surface temperatures during the migration period which decrease swimming capacity, long distances from the spawning ground to Cabot Strait and from Cabot Strait to the destination waters (especially the St Lawrence River), complex circulation patterns, and hypoxic conditions in bottom waters of the Laurentian Channel and the St Lawrence Estuary. PMID:20735683

Dutil, J-D; Dumont, P; Cairns, D K; Galbraith, P S; Verreault, G; Castonguay, M; Proulx, S

2009-06-01

4

Movement and environmental preferences of Greenland sharks ( Somniosus microcephalus ) electronically tagged in the St. Lawrence Estuary, Canada  

Microsoft Academic Search

Three Greenland sharks (Somniosus microcephalus) were tagged with electronic tags, in Baie St. Pancrace, St. Lawrence Estuary, Quebec, Canada. One shark was tagged on 23 July 2004, with an acoustic telemetry tag. Two sharks were each tagged with a pop-up satellite archival tag (PSAT) on 27 August 2004. Two of the sharks remained in or close to the bay, one

Michael J. W. Stokesbury; Chris Harvey-Clark; Jeffrey Gallant; Barbara A. Block; Ransom A. Myers

2005-01-01

5

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

6

Overview of Submarine Landslides From the Charlevoix-Kamouraska/Lower St. Lawrence Estuary Seismic Zone, Eastern Canada  

NASA Astrophysics Data System (ADS)

The Charlevoix-Kamouraska/Lower St. Lawrence Estuary seismic zone (CK/LSLE) is the most active intraplate seismic zone in Canada, where at least five earthquakes of magnitude of 6 or stronger occurred during the last 350 years. In addition, due to 1) very high sedimentation rates (as high as 30 m/ka in the St. Lawrence Estuary during deglaciation), 2) the deposition of marine clays by the Goldthwait and Laflamme postglacial Seas in the St. Lawrence Estuary and Saguenay Fjord respectively, and 3) the influence of postglacial rebound, the thick Quaternary sedimentary sequence is prone to remobilisation following strong earthquakes. Here, using recent geophysical, sedimentological and geochronological data collected during several cruises on board different research vessels, we will overview some of the Holocene and historical submarine mass wasting events recorded in the St. Lawrence Estuary and Saguenay Fjord in order to identify, characterize and date submarine landslides possibly associated with strong pre-historical and historical earthquakes. Similarly, we will also overview recent geophysical and sedimentological work conducted in lakes from the CK/LSLE seismic zone.

St-Onge, G.; Locat, J.; Lajeunesse, P.; Geneviève, C.; Gagné, H.; Sinkunas, B.; Philibert, G.; Piper, D. J.; Mulder, T.; Hillaire-Marcel, C.; Stoner, J. S.

2010-12-01

7

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

8

N2O Flux from Salt Marshes in Estuaries along the Gulf of St. Lawrence  

NASA Astrophysics Data System (ADS)

Wetlands are widely noted as filters for nutrient-laden waters. However, soils in tidal salt marshes emit nitrous oxide (N2O) when experimentally fertilized, which suggests that improved water quality comes at the expense of increased atmospheric concentrations of this potent greenhouse gas. Here we report on N2O emissions from four salt marshes located in estuaries along the Gulf of St. Lawrence. Our control site is located in a National Park on the coast of New Brunswick, which is in a region of low population density and limited agriculture, whereas the other estuaries have watersheds characterized by intensive agriculture activities on Prince Edward Island (PEI). N2O gas was collected during low tide, using opaque, static-chambers (17 L, 25 cm diameter) placed over marsh vegetation in the Spartina patens-dominated high marsh, which is typical of salt marshes along the northwest Atlantic coast, from New York north to Atlantic Canada. Preliminary analysis of gas samples collected in June revealed that the average N2O flux from the marshes located in agriculturally intensive watersheds (6.17 ×1.82 ?g N2O m-2 hr-1) was significantly higher than the flux from the control marsh, which was negligible (-2.63 ×2.22 ?g N2O m-2 hr-1). Assuming this elevated N2O flux is typical of the growing season (May-October), these marshes emit an average of 27 ×8 mg N2O m-2 yr-1 (or 8 g CO2e m-2 yr-1), 8.4% of the annual soil C accumulation rate reported for PEI. These results suggest that unintentional N fertilization of salt marshes located in agriculturally dominated watersheds may be fueling significant anthropogenic greenhouse gas emissions in some marshes. Further work during the 2013 growing season will provide insight into the environmental variables that affect the flux of N2O from these tidal salt marshes.

Roughan, B.; Kellman, L. M.; Chmura, G. L.

2013-12-01

9

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

PubMed Central

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

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

2002-01-01

10

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

SciTech Connect

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.

Brochu, C.; Moore, S. [Environment et Faune, Laval, Quebec (Canada); Pelletier, E. [INRS-Oceanologie, Rimouski, Quebec (Canada)

1995-12-31

11

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

SciTech Connect

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.

Brousseau, P.; Lapierre, P.; Guise, S. De; Beland, P.; Martineau, D.; Fournier, M. [Univ. of Quebec, Montreal, Quebec (Canada)

1995-12-31

12

Toxic chemicals and their impacts in the St. Lawrence Estuary and Saguenay Fjord, Quebec, Canada: from a chemical to an ecosystem-based risk management  

Microsoft Academic Search

The St. Lawrence Estuary (SLE) and Saguenay Fjord (SF), Quebec, Canada, have received world-wide attention in the early 1980s when high concentrations of contaminants and high prevalence of lesions including neoplasia, hermaphrodism and infection by opportunistic agents were reported in beluga whales (Delphinapterus leucas). Both persistent organic pollutants (POPs) such as PCBs mainly originating from the upstream industrialized sectors of

C. M. Couillard; M. Lebeuf

13

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

USGS Publications Warehouse

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 %).

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

1994-01-01

14

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

NASA Astrophysics Data System (ADS)

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 ?R=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.

Lajeunesse, Patrick; St-Onge, Guillaume

2013-04-01

15

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

NASA Astrophysics Data System (ADS)

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.

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

2007-12-01

16

Sediment transport in a cold climate salt marsh (St. Lawrence Estuary, Canada), the importance of vegetation and waves  

NASA Astrophysics Data System (ADS)

Salt marshes in the St. Lawrence Estuary are subjected to strong seasonal variations with sub-arctic winter conditions. The present paper explores sedimentary processes in the Pointe-aux-Épinettes marsh during the ice-free period. Currents, waves, suspended sediment, and sedimentation rates have been measured in June, August and October 2009. Vegetation growth was monitored during one year on a monthly basis to understand the seasonal impact on the marsh. Vegetation attenuates currents and waves, but this attenuation changes over the year as vegetation disappears along winter. Results show that suspended sediment transport and deposition are controlled by vegetation, wave height, currents, distance from the marsh edge and distance from sediment sources. Suspended sediment concentrations and sedimentation rates were significantly correlated to wave height, highlighting the importance of waves for sediment resuspension transport. Transport was lowest in August when vegetation was high and wave occurrence low. However, vegetation growth didn't change fundamentally sediments dynamic of the marsh. Within one tide, an important part of sediment transport is only local within the marsh, as shown by the maximum sedimentation rates occurring near unvegetated areas of the marsh. Data provide a spatial understanding of summer sedimentology on cold climate marshes.

Coulombier, Thibault; Neumeier, Urs; Bernatchez, Pascal

2012-04-01

17

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

PubMed Central

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

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

2004-01-01

18

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

NASA Astrophysics Data System (ADS)

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.

Gracia, Stéphanie; Roy, Suzanne; Starr, Michel

2013-04-01

19

Organic carbon isotope ratios and implications for the maximum turbidity zone of the St Lawrence Upper Estuary  

NASA Astrophysics Data System (ADS)

Carbon isotope ratios of suspended particulate matter of the St Lawrence Upper Estuary exhibit a different linear correlation with the ambient salinities for each sampling period, if one excludes the stations from the early mixing zone. These relationships reflect the tidal advection of particles in the turbid zone and their conservative mixing with marine inputs. The year-round constant ? 13C value of the marine pole (-23·6‰, S.D. = 0·3) is representative of an average long term mixture of terrigenous particles and planktonic cells. In May, the upstream pole (? 13C = -26·6‰) is dominated by terrigenous particulate organic carbon brought by the river with the spring freshet. After spring run-off, the sedimentary exchanges between the large tidal platforms of the Cap Tourmente region and the nearby estuarine channels control the particulate organic carbon composition of the upstream pole (? 13C = -25·4‰ in June to -24·4‰ in October). The influence of this pole extends to the entire maximum turbidity zone, blurring the isotopic characteristics of the freshwater particulate organic carbon inputs. The summer fluvial planktonic production (? 13C = -24·0‰) for instance has a negligible influence on the gradual seasonal 13C enrichment of the upstream pole. Similarly, the debris of C 3 vascular plants growing on the marshes ( Scirpus and Sagittaria) does not appear to have a dominating influence on the fall particulate organic carbon composition of the turbid zone. The 'averaged out' upstream pole reflects the long residence time (6-12 months) of the particles kept in suspension in the turbid zone.

Lueotte, Mare

1989-10-01

20

Spatial and vertical trends in sediment-phase contaminants in the upper estuary of the St. Lawrence river  

SciTech Connect

The concentration of selected contaminant trace metals and organic contaminants, namely polycyclic aromatic hydrocarbons (PAHs), normal-alkanes, total polychlorinated biphenyls (PCBs), and other organochlorines, was studied in cores from shallow-water fine-grain sediments from both sides of the maximum turbidity zone (MTZ) in the upper estuary of the St. Lawrence. Average trace metal concentrations in the cores were generally lower in downstream sediments, except for Hg and Pb. Hg levels in the cores were very high, exceeding 0.7 [mu]g g[sup [minus]1] in core C168 (south shore) and 0.19 [mu]g g[sup [minus]1] in core LE (north shore). Trace metal concentrations in all the cores were highly variable with depth, but after normalization with reference to iron, the trend was remarkably uniform, thus confirming an important inverse relationship with grain size. A similar lack of a well-defined trend was noted in the profiles of the organic components in the modern sediments. Average PAH values for modern sediments at core sites C168 and LO were 1.05 [mu]g g[sup [minus]1] and 0.44 [mu]g g[sup [minus]1], respectively (i.e., less than or equal to those in Lake Ontario and upstream in the river). PCB values far exceeded those in upstream sediments (average: 347 ng g[sup [minus]1] in core LE and 158 ng g[sup [minus]1] in C168), but were less than in Lake Ontario. Concentrations of chlordane, hexachlorobenzene, and mirex were relatively low and uniform in the modern sections of the cores. The vertical uniformity of both the contaminant profiles and those for Cs-137 (C168) suggests that the sediments are relatively young (i.e., definitely less than 35 yr at C168, and probably even less at LE and LO). Therefore no long-term or historical trend is evident. 34 refs., 11 figs., 3 tabs.

Coakley, J.P.; Nagy, E. (National Water Research Institute, Burlington, Ontario (Canada)); Serodes, J.B. (Universite Laval, Sainte-Foy, Quebec (Canada))

1993-12-01

21

First record of the green microalgae Coccomyxa sp. in blue mussel Mytilus edulis (L.) from the Lower St. Lawrence Estuary (Québec, Canada).  

PubMed

During autumn 2012 and spring 2013, blue mussels Mytilus edulis (L.) with strongly deformed (L-shaped) posterior shell margins and green spots in soft tissue (microalgae) were collected from intertidal zone along the south shore of the Lower St. Lawrence Estuary near Rimouski (Québec, Canada). Identification of algal cells infesting mussels as Coccomyxa sp. was confirmed by rRNA sequencing and HPLC pigment analysis. Flow cytometric analysis revealed the presence of algal cells in the hemolymph and extrapallial fluid in mussels with deformed and non-deformed shells; concentrations of algal cells were ranged from about 200mL(-1) in mussels with actually non-deformed shells to concentrations reaching up to 3.8×10(7)mL(-1) in mussels with heavily deformed ones. Chemical analyses of soft tissues led us to conclude that butyltin compounds and trace metals cannot be considered among factors responsible for the shell deformity observed. Using scanning electron microscopy, the biogenic nature of the erosion on the external shell surface and aragonitic lenses of prisms in the curvature zone of deformed shells (in sections) were recorded. The sequence of the green algae from M. edulis of the Lower St. Lawrence Estuary was closely related to Coccomyxa sp. infecting M. edulis from the Flensburg Fjord (North Sea) and Modiolus modiolus (L.) from the Vityaz Bay (Sea of Japan). PMID:24837974

Zuykov, Michael; Belzile, Claude; Lemaire, Nicolas; Gosselin, Michel; Dufresne, France; Pelletier, Emilien

2014-07-01

22

ST. LAWRENCE RIVER BASIN  

E-print Network

#12;983 22 ST. LAWRENCE RIVER BASIN system can travel at least 3260km from western Lake Superior the river system draws sustenance from nine states (Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio surviving record of the basin's exploration by Europeans dates to 1535, during a period of exploration

Thorp, James H.

23

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

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.

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

2000-05-01

24

Distribution and biogeochemistry of sedimentary humic substances in the St. Lawrence Estuary and the Saguenay Fjord, Québec  

Microsoft Academic Search

The concentrations of sedimentary humic substances (HS) were measured in the St. Lawrence marine system, Québec (Canada), including the Saguenay Fjord. Concentration ranges for humin, humic acids and fulvic acids were 7–49, 1–19, and 0.5–6mg per gram of sediment (dry weight), respectively. HS always represented the dominant component of sediment organic matter (SOM) (i.e., 52–100%) for which humin, humic acids,

Luc Tremblay; Jean-Pierre Gagné

2007-01-01

25

Spawning migration of American eel Anguilla rostrata from pristine (1843-1872) to contemporary (1963-1990) periods in the St Lawrence Estuary, Canada.  

PubMed

Daily American eel Anguilla rostrata catches and their dates of passage (starting, median and ending dates) were compared between pristine (1843-1872) and contemporary periods (1963-1990) to determine any changes and see whether these were related to environmental variations and water discharge regulation. Timing and duration of A. rostrata migration patterns differed significantly between the two periods. In the contemporary period, migrating A. rostrata were intercepted significantly earlier than in pristine times (18 days earlier on average), and ended at the same average period. Early A. rostrata migration was also significantly related to high spring flow and secondarily to high spring temperature, while migration ended later when high temperature or low water level occurred during the autumn period. A recent slight increase in the water temperature of the St Lawrence River could partially explain the earlier A. rostrata migration observed during the contemporary period. In return, the effect of high spring flow should have been more contrasted if the river discharge would have not been regulated. Recent A. rostrata production now being mainly restricted to the lower part of St Lawrence River mainstream, resulting shorter travelling distance to the estuary may explain why migrating progress was earlier during the contemporary period. PMID:22803716

Verreault, G; Mingelbier, M; Dumont, P

2012-07-01

26

PCBs and OCPs in sediment cores from the Lower St. Lawrence Estuary, Canada: evidence of fluvial inputs and time lag in delivery to coring sites.  

PubMed

Three sediment cores were collected along the longitudinal axis of the Laurentian Trough in the Lower St. Lawrence Estuary (LSLE) and an additional one at the junction of the Estuary and the Gulf of St. Lawrence. After core-slicing, each sediment layer was analyzed for polychlorinated biphenyls (PCBs) and some organochlorine pesticides (OCPs) including p,p'-dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB) and Mirex. 210Pb activity was also measured in these sediments, which allowed us to confirm that these cores were too much affected by the overall impact of surface mixing to be dated. Nevertheless, POP sedimentary profiles in cores from the LSLE upstream stations showed well-defined subsurface peak concentrations. Apparently, the peak inputs of POPs to these sediment cores had occurred after the years of maximum sales and production of these chemicals in North America, suggesting a time lag in the delivery of POPs to the LSLE sediments. Concentrations of POPs in the LSLE surface sediments as well as POP inventories in sediment cores decreased in the seaward direction, confirming that the head of the LSLE acts as a sink for sediments and associated constituents. Surface concentrations of sigmaPCBs, sigmaDDTs, and HCB in the most upstream core were on average similar to those reported in two fluvial lakes of the St. Lawrence River but were between 12 and 39 times lower than those from Lake Ontario. For Mirex, the surface concentration in that core was 5 and 130 times lower than the average values found in the fluvial lakes and Lake Ontario, respectively. Differences between Lake Ontario sediment cores and the most upstream core from the LSLE were much smaller on the basis of POP inventories than surface concentrations of POPs, but were still important. The total burdens of POPs in LSLE sediments below the 200 m isobath were 8704 kg for sigmaPCBs, 1825 kg for sigmaDDTs, 319 kg for HCB, and 27.5 kg for Mirex. These values represent between 1% and 10% of the total burdens of these POPs in Lake Ontario sediments. The estimated contribution of POPs by direct atmospheric deposition into the water column area of the LSLE represented at most 30% of the total sediment burdens of POPs in the LSLE, illustrating the importance of fluvial inputs. PMID:15819199

Lebeuf, Michel; Nunes, Teresa

2005-03-15

27

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)

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.

Scheifele, Peter Martin

2003-06-01

28

Reproductive System Impairment of Mice Fed Diets Containing Beluga Whale Blubber from the St. Lawrence Estuary and Arctic Populations  

Microsoft Academic Search

The toxic potential of naturally relevant mixtures of PCBs and other organohalogens on the reproductive system of C57Bl\\/6 female mice was assessed. Mice were fed diets in which lipids were replaced by blubber of beluga whales from a highly contaminated population of the Saint Lawrence River, and a less contaminated population from the Arctic Ocean. Ratios of blubber from both

Sylvia Ruby; Luz Tavera Mendoza; Michel Fournier; Pauline Brousseau; V. Dégas

2003-01-01

29

Immunosuppression in mice fed on diets containing beluga whale blubber from the St Lawrence Estuary and the Arctic populations  

Microsoft Academic Search

In order to assess the immunotoxic potential of naturally relevant mixtures of PCBs and other organohalogens, C57Bl\\/6 mice were fed on diets in which lipids were replaced by blubber of beluga whales from the highly contaminated population of the Saint-Lawrence River, and the less contaminated population from the Arctic. Different ratios of blubber from both sources were mixed in order

M Fournier; V Dégas; T Colborn; F. O Omara; F Denizeau; E. F Potworowski; P Brousseau

2000-01-01

30

Mid and late Holocene dust deposition in eastern Canada - a preliminary multi-proxy record from the Baie bog (St. Lawrence Estuary, Quebec)  

NASA Astrophysics Data System (ADS)

Atmospheric mineral dust plays an important role in the Earth's climate through parameters such as atmospheric radiation, cloud properties and biogeochemical cycles. However, the high spatial and temporal variability of mineral dust and a lack of terrestrial archives in certain regions limit our understanding global dust-climate interactions. Ombrotrophic peatlands (bogs; atmospherically-fed only) are increasingly recognized as archives of atmospheric dust deposition. Their global distribution and high accumulation rates (i.e. high resolution) over the Holocene make them suitable substitute to marine and/or ice records. The Baie bog, located along the St. Lawrence Estuary (North Shore region, Quebec, Canada), was sampled to investigate dust deposition/palaeowinds in north eastern North America over the mid and late Holocene. The core was subsampled for elemental and isotopic geochemistry as well as particle size analyses, 210Pb and radiocarbon dating. Radiocarbon dating of the base of the peat sequence yielded an age of about 4300 yr cal BP. Initial results show periods of increased dust flux, calculated from REE concentrations, between 1000-1500 yr cal BP and 100-500 yr cal BP in the peat profile from 0.5 to 4 g m-2 yr-1. Higher dust fluxes usually occur in combination with greater particle size suggesting either stronger winds or a change of source. Periods of increased dust fluxes in the profile also correspond with changes in the macrofossil assemblages. A first attempt at source tracing through preliminary radiogenic isotopes analyses (Pb, Nd; ongoing) will also be discussed.

Pratte, Steve; Garneau, Michelle; De Vleeschouwer, François

2014-05-01

31

Dissolved mercury behaviour in the Saint Lawrence estuary  

NASA Astrophysics Data System (ADS)

Dissolved mercury concentrations have been measured in the waters of the St Lawrence estuary. The typical concentration of the riverine end-member is 12·0±3·0 p M; the oceanic end-member samples exhibit a mean mercury concentration of 2·4 p M. The graphical pattern of the relationship between mercury concentration and salinity shows a departure from a dilution line. We suggest that a removal of mercury from the dissolved phase during the estuarine mixing is responsible for this observation. Based on the results, the actual input of dissolved mercury from the St Lawrence River to the Gulf is evaluated to be approximately 0·52 T a -1.

Cossa, Daniel; Gobeil, Charles; Courau, Philippe

1988-02-01

32

Reproductive system impairment of mice fed diets containing beluga whale blubber from the St Lawrence estuary and arctic populations.  

PubMed

The toxic potential of naturally relevant mixtures of PCBs and other organohalogens on the reproductive system of C57Bl/6 female mice was assessed. Mice were fed diets in which lipids were replaced by blubber of beluga whales from a highly contaminated population of the Saint Lawrence River, and a less contaminated population from the Arctic Ocean. Ratios of blubber from both sources were mixed in order to perform a dose-response study. Control mice were fed diets for 90 d in which fat was replaced by corn oil or beef tallow. There were no significant effects of diets on body, liver, spleen or thymus weights. Similarly ovulation occurred in all control and experimental groups. However, Graafian follicles from ovaries of mice fed contaminated diets showed abnormal development of oocytes. Cumulus granulosa cells bind normally to the oocyte prior to ovulation and are essential for sperm penetration and fertilization. These cells were absent in both Graafian follicles and ovulated oocytes in the oviduct of all groups fed contaminated diets. Oviducts of these mice revealed evidence of epithelial degeneration. These results suggest the female mouse reproductive system is sensitive to organohalogens and illustrate the toxic potential of contaminant mixtures as found in the less contaminated Arctic population. PMID:12775517

Ruby, Sylvia; Mendoza, Luz Tavera; Fournier, Michel; Brousseau, Pauline; Dégas, V

2003-06-13

33

Cooling in the Gulf of St. Lawrence and estuary region at 9.7 to 7.2 14C ka (11.2–8.0 cal ka): Palynological response to the PBO and 8.2 cal ka cold events, Laurentide Ice Sheet air-mass circulation and enhanced freshwater runoff  

Microsoft Academic Search

An examination of post-Younger Dryas (YD) pollen stratigraphies in the Gulf of St. Lawrence and St. Lawrence estuary region reveals features in the pollen records that represent breaks in the normal vegetation succession, widespread vegetation suppression, and a delay in migration of plant taxa between 9.7 and 7.2 14C ka (11.2 and 8.0 cal ka). The domination of Alnus crispa at

Thane W. Anderson; Elisabeth Levac; C. F. Michael Lewis

2007-01-01

34

Immunosuppression in mice fed on diets containing beluga whale blubber from the St Lawrence estuary and the Arctic populations.  

PubMed

In order to assess the immunotoxic potential of naturally relevant mixtures of PCBs and other organohalogens, C57Bl/6 mice were fed on diets in which lipids were replaced by blubber of beluga whales from the highly contaminated population of the Saint-Lawrence River, and the less contaminated population from the Arctic. Different ratios of blubber from both sources were mixed in order to allow a dose-response study. Mice were fed for a period of 90 days at the end of which their immunological status was monitored. For general parameters such as body weight, weight of the spleen and the thymus no significant effect of diets were observed. The immunological endpoints such as the blastic transformation of splenocytes and the spleen NK cell activity were not significantly affected by any of the diets compared to control diets. While the different cell subpopulations of peripheral blood and thymus were not affected by the diets, a significant decrease was noted in the CD8+ T cell population in the spleen of mice fed with most of the diets containing beluga blubber. Moreover, the ability of splenic cells to elicit humoral response against sheep red blood cells as well as the potential of peritoneal macrophages to perform phagocytosis were suppressed by all diets containing beluga blubbers. In summary, there was no differences between the groups fed with a blubber diet with low and high organochlorine contamination. However, a clear immunosuppression was demonstrated when these groups were compared to the group fed with beef oil. Despite the fact that we cannot exclude a possible contribution of the fatty acid composition of the beluga blubber to the immunosupression, these results suggest the sensitivity of mouse immune system towards organohalogens, and point out the toxic potential of contaminant mixtures as found in the less contaminated Arctic population. PMID:10720746

Fournier, M; Dégas, V; Colborn, T; Omara, F O; Denizeau, F; Potworowski, E F; Brousseau, P

2000-03-15

35

Invasion of the southern Gulf of St. Lawrence by the clubbed tunicate ( Styela clava Herdman): Potential mechanisms for invasions of Prince Edward Island estuaries  

Microsoft Academic Search

All but one of the nine non-native marine species that established populations in the southern Gulf of St. Lawrence (sGSL) in the past decade initially invaded the sGSL via coastal and estuarine waters of Prince Edward Island (PEI). Almost half of these species are tunicates, and all but one still occur only in PEI. Recent introductions include Styela clava Herdman

Andrea Locke; J. Mark Hanson; Karla M. Ellis; Jason Thompson; Rémy Rochette

2007-01-01

36

14C and 13C Contents of Dissolved Organic Matter in the St. Lawrence Estuary and in a Hydroelectric Reservoir From the Boreal Forest (Quebec)  

NASA Astrophysics Data System (ADS)

In this study we examine the 14C and 13C contents of Dissolved Organic Matter (DOM) in the St. Lawrence River, at its outlet near Quebec City, and in a large hydroelectric reservoir, from the Canadian Boreal forest (Robert-Bourassa reservoir) as a mean to document the origin and residence time of DOM in such large catchments. Samples of DOM were collected bi-weekly at the Quebec City station from November 2001 until November 2002, as part of a geochemical monitoring program of the river, carried out since 1997. At the Robert-Bourassa reservoir, sampling operations took place from July 15 to July 26, 2001. All samples were filtered and acidified on site, and preserved in brown glass bottles at 4° C. Prior to their isotopic analysis, DOM samples were freeze-dried. 13C analyses were made at GEOTOP whereas 14C measurements were performed at the Lawrence Livermore National Laboratory, for samples coming from the St. Lawrence River, and at the Laboratoire d'Hydrologie et de géochimie isotopique of University Paris XI for samples originating from the Robert-Bourassa reservoir. Results are expressed respectively in ‰ vs. V-PDB and in % of modern carbon (% MC; i.e. 13.56 dpm/g C in 1950, for d13C=-25 ‰ ). D13C values averaging -26.3 ± 0.2 ‰ in the St. Lawrence, and -27.1 ± 0.2 ‰ at the Robert-Bourassa reservoir, indicate that DOC originates from terrestrial production, although a slight influence of aquatic DOC is seen in the St. Lawrence river during low water level episodes. In the river, DOC-14C activities range from 97.7 to 106.7 ± 0.5 %, with a mean value of 103.9 ± 0.5 %, whereas samples from Robert-Bourassa reservoir show a range of values between 108.5 and 110.5 ± 0.9 %, with a mean of 109.5 ± 0.9 %. In comparison, measurements made during the late 80's, in a small brook of Ontario, yielded 14C-DOM activities ranging from 113 to 118 % MC (Schiff et al., 1990). Meanwhile, 14C-activity of atmospheric CO2 has decreased of approximately the same proportion. We conclude that soil-derived DOC represents the production of immediately preceding years, notably in the Boreal Forest reservoir, but that contribution of longer residence time DOC from the Great Lakes likely accounts for the slightly lower 14C-DOC values found in the St. Lawrence River. In conclusion, 14C and 13C contents indicate an overall short DOM residence time, thus that the primary production at its origin, and its degradation and transport in the drainage network are fast processes. Reference: Schiff, S. L., R. Aravena, S. E. Trumbore et P. J. Dillon. 1990. Dissolved organic carbon cycling in forested watersheds : a carbon isotope approach. Water Resources Research, 26, no 12, 2949-2957.

Lamontagne, J.; Hélie, J.; Hillaire-Marcel, C.

2004-05-01

37

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

SciTech Connect

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.

Guise, S. De; Fournier, M. [Univ. du Quebec, Montreal, Quebec (Canada); Martineau, D. [Univ. de Montreal, St-Hyacinthe, Quebec (Canada); Beland, P.

1995-12-31

38

Evaluating long-term regional climate variability in the maritime region of the St. Lawrence North Shore  

E-print Network

(bogs) along the north shore of the Estuary and the Gulf of St. Lawrence in eastern Canada. Past waterEvaluating long-term regional climate variability in the maritime region of the St. Lawrence North Shore (eastern Canada) using a multi-site comparison of peat-based paleohydrological records GABRIEL

39

Assessment of Salinity-Related Mortality of Freshwater Bacteria in the Saint Lawrence Estuary  

Microsoft Academic Search

ThegrowthresponseoffreshwaterbacteriafromtheSt.LawrenceRiver,exposedtobrackishwaters(salinity of 0 to 20‰) from the upper estuary, was assessed by a methodology requiring the combined use of dilution cultures and diffusion chambers. The longitudinal distribution of bacterial abundance in waters within this salinityrangewasalsoexamined.Growthofthefreshwaterbacteriawasreducedby15and50%afterexposure tosalinitiesof10and20‰,respectively.Atlowersalinities,nogrowthreductionwasobserved,andatasalinity of 2‰, growth was even stimulated. Longitudinal distribution data showed that bacterial abundance also peaked at this salinity. In contrast with an earlier hypothesis,

JEAN PAINCHAUD; JEAN-CLAUDE THERRIAULT; ANDLOUIS LEGENDRE

1995-01-01

40

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

Microsoft Academic Search

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

P. Beland; R. Michaud; S. DeGuise; C. Girard; A. Lagace; D. Martineau; Derek C. G. Muir; R. J. Norstorm; E. Pelletier; Sankar Ray

1993-01-01

41

Sivuqam Ungipaghaatangi (St. Lawrence Island Legends).  

ERIC Educational Resources Information Center

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…

Slwooko, Grace

42

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

SciTech Connect

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.

Beland, P.; Michaud, R. (St. Lawrence National Inst. of Ecotoxicology, Montreal, Quebec (Canada)); DeGuise, S. (St. Lawrence National Inst. of Ecotoxicology, Montreal, Quebec (Canada) Faculte de Medecine Veterinaire, St-Hyacinthe, Quebec (Canada)); Girard, C.; Lagace, A. (Faculte de Medecine Veterinaire, St-Hyacinthe, Quebec (Canada)); Martineau, D. (St. Lawrence National Inst. of Ecotoxicology, Montreal, Quebec (Canada) Cornell Univ., Ithaca, NY (United States)); Muir, D.C.G. (Freshwater Inst., Winnipeg, Manitoba (Canada)); Norstorm, R.J. (National Wildlife Research Center, Hull, Quebec (Canada)); Pelletier, E. (INRS-Oceanologie, Rimouski, Quebec (Canada)); Ray, S. (Fisheries and Oceans Canada, St. John's, Newfoundland (Canada)) (and others)

1993-01-01

43

New York Landscape Regions in Google Earth: St. Lawrence Lowlands  

NSDL National Science Digital Library

The St. Lawrence Lowlands tour is part of the New York Landscape Regions Collection of Google Earth Tours. This tour allows students to explore the Thousand Islands, formed of granite which has withstood the erosive energy of the St. Lawrence River, creating thousands of islands ranging in size from single rocks to over 25 square miles. There is also an activity in which students map some of the many shipwrecks that have accumulated at the entrance to the St. Lawrence Seaway.

44

Great Lakes St. Lawrence Seaway System  

NSDL National Science Digital Library

The Great Lakes St. Lawrence Seaway connects the Atlantic Ocean to the Great Lakes, and it was completed in 1959. This website details the activities of the Seaway System, and visitors with an interest in transportation and public policy will find the site both useful and interesting. At the top of the homepage, visitors will find the five primary sections of the site, which include "Management of the Seaway" and "Commercial Shipping". First-time visitors should start at "The Seaway" section. Here they will find the interactive "Gateway to North America" tour, along with information on the System's locks and channels and a nice "Facts and Figures" area. The site also contains thematic collections of information designed for business people, students and educators, and the media. Visitors who wish to stay abreast of System activities can sign up for email updates on the homepage. Francophone users will be glad to learn that the entire site is also available in French.

45

An empirical approach to the remote sensing of the chlorophyll in the optically complex waters of the Estuary and Gulf of Saint-Lawrence  

Microsoft Academic Search

Data from five research cruises performed between 1997 and 2001 were processed in order to investigate the potential for improving remote sensing algorithms in the Estuary and Gulf of St. Lawrence. Measured in situ parameters included concentration-dependent indicators of the three critical, optically-active constituents, chlorophyll, Coloured Dissolved Organic Matter (CDOM) and Suspended Particulate Matter (SPM). The radiometric dataset used to

K. Mehmet Yayla

2009-01-01

46

Assessment of Salinity-Related Mortality of Freshwater Bacteria in the Saint Lawrence Estuary  

PubMed Central

The growth response of freshwater bacteria from the St. Lawrence River, exposed to brackish waters (salinity of 0 to 20(permil)) from the upper estuary, was assessed by a methodology requiring the combined use of dilution cultures and diffusion chambers. The longitudinal distribution of bacterial abundance in waters within this salinity range was also examined. Growth of the freshwater bacteria was reduced by 15 and 50% after exposure to salinities of 10 and 20(permil), respectively. At lower salinities, no growth reduction was observed, and at a salinity of 2(permil), growth was even stimulated. Longitudinal distribution data showed that bacterial abundance also peaked at this salinity. In contrast with an earlier hypothesis, this study shows that the decline of bacterial abundance in the low-salinity waters of the estuary is not caused by salinity-related mortality of freshwater bacteria, because the mixing time between fresh and marine (>20(permil)) waters is relatively long (days). However, results suggest that mortality of freshwater bacteria can be an important process in estuaries with shorter mixing times (hours). The combined use of diffusion chambers and dilution cultures proved to be a valuable methodology for assessing growth (or mortality) of bacteria exposed to environmental gradients. PMID:16534903

Painchaud, J.; Therriault, J.; Legendre, L.

1995-01-01

47

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

NASA Astrophysics Data System (ADS)

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. .

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

2005-03-01

48

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

PubMed

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

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

2005-03-01

49

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

PubMed

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

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

2006-10-01

50

Stocking young Atlantic salmon in St. Lawrence River system  

USGS Multimedia Gallery

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...

51

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

SciTech Connect

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}.

Phaneuf, D.; Cote, I.; Dumas, P.; Ferron, L.A.; LeBlanc, A. [CHUQ, Sainte-Foy, Quebec (Canada). Centre de Toxicologie du Quebec] [CHUQ, Sainte-Foy, Quebec (Canada). Centre de Toxicologie du Quebec

1999-02-01

52

Supracrustal faults of the St. Lawrence rift system, Québec: kinematics and geometry as revealed by field mapping and marine seismic reflection data  

NASA Astrophysics Data System (ADS)

The St. Lawrence rift system from the Laurentian craton core to the offshore St. Lawrence River system is a seismically active zone in which fault reactivation is believed to occur along late Proterozoic to early Paleozoic normal faults related to the opening of the Iapetus ocean. The rift-related faults fringe the contact between the Grenvillian basement to the NW and Cambrian-Ordovician rocks of the St. Lawrence Lowlands to the SE and occur also within the Grenvillian basement. The St. Lawrence rift system trends NE-SW and represents a SE-dipping half-graben that links the NW-SE-trending Ottawa-Bonnechère and Saguenay River grabens, both interpreted as Iapetan failed arms. Coastal sections of the St. Lawrence River that expose fault rocks related to the St. Lawrence rift system have been studied between Québec city and the Saguenay River. Brittle faults marking the St. Lawrence rift system consist of NE- and NW-trending structures that show mutual crosscutting relationships. Fault rocks consist of fault breccias, cataclasites and pseudotachylytes. Field relationships suggest that the various types of fault rocks are associated with the same tectonic event. High-resolution marine seismic reflection data acquired in the St. Lawrence River estuary, between Rimouski, the Saguenay River and Forestville, identify submarine topographic relief attributed to the St. Lawrence rift system. Northeast-trending seismic reflection profiles show a basement geometry that agrees with onshore structural features. Northwest-trending seismic profiles suggest that normal faults fringing the St. Lawrence River are associated with a major topographic depression in the estuary, the Laurentian Channel trough, with up to 700 m of basement relief. A two-way travel-time to bedrock map, based on seismic data from the St. Lawrence estuary, and comparison with the onshore rift segment suggest that the Laurentian Channel trough varies from a half-graben to a graben structure from SW to NE. It is speculated that natural gas occurrences within both the onshore and offshore sequences of unconsolidated Quaternary deposits are possibly related to degassing processes of basement rocks, and that hydrocarbons were drained upward by the rift faults.

Tremblay, Alain; Long, Bernard; Massé, Manon

2003-07-01

53

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

Code of Federal Regulations, 2013 CFR

... St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...St. Lawrence Island Habitat Conservation Area Longitude Latitude...

2013-10-01

54

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

Code of Federal Regulations, 2010 CFR

... St. Lawrence Island Habitat Conservation Area 45 Table 45 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...St. Lawrence Island Habitat Conservation Area Longitude Latitude...

2010-10-01

55

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

E-print Network

Holocene development of maritime ombrotrophic peatlands of the St. Lawrence North Shore in eastern; Glaser, 1992). Ombrotrophic peatlands (bogs) are widespread along the north shore of the St. Lawrence

56

Groundwater quality in the Delaware and St. Lawrence River Basins, New York, 2010  

USGS Publications Warehouse

Water quality in both study areas is generally good, but concentrations of some constituents equaled or exceeded current or proposed Federal or New York State drinking-water standards. The standards exceeded are color (one sample in the St. Lawrence study area), pH (three samples in the Delaware study area), sodium (one sample in the St. Lawrence study area), total dissolved solids (one sample in the St. Lawrence study area), aluminum (one sample in the Delaware study area and one sample in the St. Lawrence study area), iron (seven samples in the St. Lawrence study area), manganese (one sample in the Delaware study area and five samples in the St. Lawrence study area), gross alpha radioactivity (one sample in the St. Lawrence study area), radon-222 (10 samples in the Delaware study area and 14 samples in the St. Lawrence study area), and bacteria (

Nystrom, Elizabeth A.

2012-01-01

57

A Study of the St. Lawrence River Ecological Habitat  

NSDL National Science Digital Library

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

Maria Mesires

2010-03-01

58

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

ERIC Educational Resources Information Center

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.

Abraham, Jane; Cooper, Mabel; Ferris, Gloria

2010-01-01

59

A Study of the St. Lawrence River Ecological Habitat  

ERIC Educational Resources Information Center

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…

Mesires, Maria

2010-01-01

60

RAPID COMMUNICATION Microplastic pollution in St. Lawrence River sediments  

E-print Network

RAPID COMMUNICATION Microplastic pollution in St. Lawrence River sediments Rowshyra A. Castañeda ecosystems, microplastic pollution has only recently been documented in freshwater environments, almost exclusively in surface waters. Here, we report microplastics (polyethylene microbeads, 0.40­ 2.16 mm diameter

Ricciardi, Anthony

61

Knowing, mapping and understanding St. Lawrence biodiversity, with special emphasis on bird assemblages.  

PubMed

Environment Canada and the Québec Department of the Environment, partners in the St Lawrence Vision 2000 Action Plan, set out to prepare a compendium of knowledge of the flora and fauna of the St Lawrence and to identify potential conservation sites. The resulting Portrait is an Internet site that presents the current knowledge base of the river's ecological and biological diversity (http://lavoieverte.qc.ec.gc.ca/faune/biodiv/index.html). The Portrait provides information on over 5,000 species of flora and fauna. On the website, you will find a detailed ecological analysis of the richness, rarity and vulnerability of several broad groups of plant and animal species. Furthermore, you will find a list of species for each of the 700 survey units and a distribution map for 2,500 species recorded along the St Lawrence., in atlas form, along with a detailed conservation plan. The plan encompasses the most unique and heterogeneous landscapes of the St Lawrence, some of which have no protection at present. The Portrait provides an overview of the sites that are currently protected by public agencies and private-sector organisations and identifies new sites of interest for conserving biodiversity and protecting species at risk. This paper exposes the content of this extensive compendium on the biodiversity of the St. Lawrence. For conciseness, it presents some of the analyses conducted on birds to illustrate a few of the analytical approaches that were used. Then, the information on species richness and concentration areas for priority species of vascular plants, breeding birds and herpetofauna will serve to identify the terrestrial sites of significance for biodiversity. Finally, a similar approach having been applied to the aquatic environnement, we will conclude with a conservation plan that identifies the terrestrial and aquatic ecosystems, and the geographic sites where the most important elements of St. Lawrence biodiversity are concentrated. Our analysis of the biodiversity of the most thoroughly studied taxa of the St. Lawrence clearly shows the importance of wetlands, particularly those located at the mouths of rivers or within archipelagos or delta complexes, such as the groups of islands and channels found at both ends of the Montreal Archipelago. These aquatic landscapes are sites of intense biological production, combining in a small geographical area spawning, nursery and feeding grounds for a large number of fish species and breeding, rearing and foraging areas for aquatic birds. Variable flooding conditions, associated with seasonal flooding or daily tidal fluctuations, create a complex mosaic of wetland and aquatic habitats. Although wetlands occupy only a small area in comparison with terrestrial habitats, they support a large number of rare plant and animal species in relation to their size. At present, 10% of the vascular flora and 27% of the herpetofauna of the St. Lawrence are at risk. In the case of reptiles and amphibians, the situation is especially worrisome because nearly all of the most threatened species live in a narrow band along the river corridor. Not only is this the sector that is under the greatest pressure from human development, very little public land remains here, making it difficult to create protected areas. Increased participation by non-governmental organisations and individuals, through private stewardship arrangements, is an essential precondition for completing the network of conservation areas in this part of the St. Lawrence. Along the estuary and the Gulf, habitat integrity has not been affected as much by the expansion of Québec's human population. This is a vast territory, and sites have been identified with a view to making up for the deficiencies in the present network of protected sites in terms of representing biodiversity. PMID:14570415

Desgranges, Jean-Luc; Jobin, Benoît

2003-01-01

62

Relationships between metallothionein induction, cadmium, copper and zinc levels and environmental parameters in the soft shell clam Mya arenaria in the Saguenay fjord and the St. Lawrence River maritime estuary  

Microsoft Academic Search

Physiological status of Mya arenaria is threatened in the Saguenay-Saint Lawrence system due to inputs of many kinds of pollutants from anthropogenic and industrial origins. Investigations of the health of M. arenaria were carried out using metallothioneins concentrations as biomarkers of metallic contamination in relation with concentrations of metals.

Jocelyne Pellerin; Jean-Claude Amiard

2008-01-01

63

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

NASA Astrophysics Data System (ADS)

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.

Magnan, Gabriel; Garneau, Michelle; Payette, Serge

2014-07-01

64

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...

65

Sources and fluxes of mercury in the St. Lawrence River  

SciTech Connect

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.

Quemerais, B.; Rondeau, B.; Pham, T.T.; Gagnon, P.; Fortin, B. [Environment Canada, Montreal, Quebec (Canada). St. Lawrence Centre] [Environment Canada, Montreal, Quebec (Canada). St. Lawrence Centre; Cossa, D. [Inst. Francais de Recherche pour l`Exploitation de la Mer, Nantes (France)] [Inst. Francais de Recherche pour l`Exploitation de la Mer, Nantes (France)

1999-03-15

66

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

Federal Register 2010, 2011, 2012, 2013, 2014

...display will be held on the waters of the St. Lawrence...The Captain of the Port Buffalo has determined that fireworks...the Captain of the Port Buffalo has determined that a...zone will encompass all waters of the St. Lawrence...the Captain of the Port Buffalo or his designated...

2012-06-28

67

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

Federal Register 2010, 2011, 2012, 2013, 2014

...The Captain of the Port Buffalo has determined that fireworks...It would encompass all waters of St. Lawrence River...the Captain of the Port Buffalo or his on-scene representative...zone will encompass all waters of the St. Lawrence...the Captain of the Port Buffalo or his designated...

2012-05-23

68

Organochlorine and Metal Contaminants in Traditional Foods from St. Lawrence Island, Alaska  

Microsoft Academic Search

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

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

2011-01-01

69

ST. LAWRENCE ISLANDS NATIONAL PARK OF CANADA MALLORYTOWN LANDING, ONTARIOVOL. 1, NO. 1 SPRING 2006  

E-print Network

ST. LAWRENCE ISLANDS NATIONAL PARK OF CANADA MALLORYTOWN LANDING, ONTARIOVOL. 1, NO. 1 SPRING 2006 No longer the smallest! More hiking trails as park doubles in size What was once Canada's smallest national park has dou- bled in size. In November 2005, St. Lawrence Islands National Park expanded to include 10

Blouin-Demers, Gabriel

70

ST. LAWRENCE ISLANDS NATIONAL PARK OF CANADA MALLORYTOWN LANDING, ONTARIOVOL. 1, NO. 2 FALL 2006  

E-print Network

ST. LAWRENCE ISLANDS NATIONAL PARK OF CANADA MALLORYTOWN LANDING, ONTARIOVOL. 1, NO. 2 FALL 2006 A national park on your doorstepIN THIS ISSUE Best view of the islands....12 Turtle study saves lives.......3.....................................12 St. Lawrence Islands National Park 2 County Rd. 5, R.R.#3 Mallorytown, ON K0E 1R0 (613) 923

Blouin-Demers, Gabriel

71

NOAA Technical Memorandum ERL GLERL-104 GREAT LAKES AND ST. LAWRENCE RIVER MEDIUM RESOLUTION VECTOR  

E-print Network

NOAA Technical Memorandum ERL GLERL-104 GREAT LAKES AND ST. LAWRENCE RIVER MEDIUM RESOLUTION VECTOR SHORELINE DATA D.H. LEE NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI C. MORSE, and S ............................................................................................................................................. 4 2. Great Lakes-St. Lawrence River Vector Shoreline Data

72

Pristine Lake Saint-François, St. Lawrence River: Hydrodynamic Simulation and Cumulative Impact  

Microsoft Academic Search

Lake Saint-François is a fluvial lake of the St. Lawrence system which is used for hydropower production and commercial navigation. For 150 years, it was dredged and dammed regularly without any impact analysis being made. The cumulative impact of dredging and damming on large rivers such as the St. Lawrence is an issue with only qualitative answers. Bidimensional hydrodynamics was

Jean Morin; Paul Boudreau; Yves Secretan; Michel Leclerc

2000-01-01

73

Bioassessment of Benthic Macroinvertebrates in Wetland Habitats of Lake Saint-Pierre (St. Lawrence River)  

Microsoft Academic Search

We evaluated the potential of vegetation and sediment habitats in wetlands of the St. Lawrence River for developing a macroinvertebrate bioassessment program with reference conditions. During September 2004, we collected macroinvertebrates in emergent vegetation and sediment in both fluvial sites (reference) and tributary-plume sites (impacted) in waters of the north and south shores of Lake Saint-Pierre (St. Lawrence River). In

Laure Tall; Ginette Méthot; Alain Armellin; Bernadette Pinel-Alloul

2008-01-01

74

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

PubMed Central

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

Fox, G A

2001-01-01

75

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

NASA Astrophysics Data System (ADS)

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.

Berchok, Catherine L.

76

Earthquakes and Geological Structures of the St. Lawrence Rift System  

NASA Astrophysics Data System (ADS)

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.

Lamontagne, M.; Ranalli, G.

2013-12-01

77

Field measurements of ship waves along the St. Lawrence river waterway, Canada  

Microsoft Academic Search

Coastal erosion along the St. Lawrence river waterway in Quebec, Canada, represents a hazard to local communities living along the river banks, as well as to the local fauna habitat. The purpose of this study is to assess the potential impact of longer containerships on riverbank erosion and recession at critical sites along the Saint Lawrence river waterway. A field

S. Gharbi; S. Hamdi; G. Valkov; I. Nistor

2008-01-01

78

Comparison of St. Lawrence blue whale vocalizations with field observations  

NASA Astrophysics Data System (ADS)

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.

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

2003-04-01

79

Temporal Regionalization of 7Day Low Flows in the St. Lawrence Watershed in Quebec (Canada)  

Microsoft Academic Search

Winter and summer 7-day low flows of eighteen natural rivers in the St. Lawrence River watershed of Quebec were analyzed over\\u000a the period from 1934 to 2000. The rivers were first subdivided into three modes using principal component analysis. Two of\\u000a these modes are located on the south shore of the St. Lawrence River, respectively south (Southeast mode) and north

Ali Arkamose Assani; Alain Chalifour; Guillaume Légaré; Caza-Szoka Manouane; Denis Leroux

80

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

PubMed

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

Mouy, Xavier; Bahoura, Mohammed; Simard, Yvan

2009-12-01

81

The Larval Fish Assemblage in Nearshore Coastal Waters off the St Lucia Estuary, South Africa  

Microsoft Academic Search

This paper reports on the composition, abundance and distribution of the larval fish assemblage in the nearshore coastal waters off the St Lucia Estuary mouth, South Africa. Ichthyoplankton samples were collected over a 12 month period from five stations located along a transect up to 2·5km offshore, and from two stations north and south of the estuary mouth, respectively. In

S. A Harris; D. P Cyrus; L. E Beckley

1999-01-01

82

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 ...

83

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

USGS Publications Warehouse

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.

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

2008-01-01

84

Basis of comparison Great Lakes-St. Lawrence River system. Technical memo  

SciTech Connect

A 90-year set of lake levels and flows has been developed that reflects a consistent hydraulic regime in the Great Lakes-St. Lawrence Riversystem. The hydraulic regime is defined by the diversion rates into and out of the system, consumptive use withdrawals from the system, the time series of water supplies to the system, outlet conditions of each lake, flow retardation due to ice or weeds in the connecting channels, initial starting elevations for the simulation, the hydraulic condition of the St. Lawrence River, and tidal levels at its outlet. These levels and flows can be used as a reference for assessing the effects of modified lake regulation and climate change.

Lee, D.H.

1993-04-01

85

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)

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.

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

2009-01-01

86

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

PubMed

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

McQuinn, Ian H; Lesage, Véronique; Carrier, Dominic; Larrivée, Geneviève; Samson, Yves; Chartrand, Sylvain; Michaud, Robert; Theriault, James

2011-12-01

87

Exploratory multiscale analysis of the fish assemblages and habitats of the lower St. Lawrence River, Québec, Canada  

Microsoft Academic Search

.  This work presents a multiscale analysis of the fish diversity of the lower St. Lawrence River which flows from the Laurentian Great Lakes of North America. A database of about 14,000 fish sampling stations from the lower St. Lawrence is linked to five different habitat maps of the study area: hydrographical units, water masses, depth, sediment type and wetland type.

Jacques Leclerc; Jean-Luc DesGranges

2005-01-01

88

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

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.

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

2011-01-01

89

Binational GIS database of coastal wetlands for Lake Ontario and the St. Lawrence: a demonstration project  

E-print Network

Binational GIS database of coastal wetlands for Lake Ontario and the St. Lawrence: a demonstration wetlands of Lake Ontario in ArcMap (ESRI). Information for the Canadian wetlands were obtained from two Canada, along with wetland polygons from the Ontario Ministry of Natural Resources, and geographic

McMaster University

90

The St. Lawrence polynya and the Bering shelf circulation: New observations and a model comparison  

Microsoft Academic Search

Using 14 yearlong instrumented moorings deployed south of St. Lawrence Island, along with oceanographic drifters, we investigate the circulation over the central Bering shelf and the role of polynyas in forming and disseminating saline waters over the shelf. We focus also on evaluating the Gawarkiewicz and Chapman (1995) model of eddy production within coastal polynyas. Principal results include the following.

S. Danielson; K. Aagaard; T. Weingartner; S. Martin; P. Winsor; G. Gawarkiewicz; D. Quadfasel

2006-01-01

91

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 ...

92

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

SciTech Connect

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.

Champoux, L.; DesGranges, J.L.; Rodrigue, J. [Canadian Wildlife Service, Ste-Foy, Quebec (Canada); Trudeau, S. [Canadian Wildlife Service, Hull, Quebec (Canada); Hontela, A.; Boily, M.; Spear, P.A. [Univ. du Quebec, Montreal, Quebec (Canada)

1995-12-31

93

Physical factors affecting the relative abundance of native and invasive amphipods in the St. Lawrence River  

Microsoft Academic Search

The Ponto-Caspian amphipod Echinogammarus ischnus (Stebbing, 1899) is reportedly replacing the North American amphipod Gammarus fasciatus Say, 1818, in the lower Great Lakes, but the two species appear to coexist in the upper St. Lawrence River several years after invasion by E. ischnus. A multi-site survey in the river between Lake Ontario and Montreal (Quebec) found that E. ischnus and

M. E. Palmer; A. Ricciardi

2004-01-01

94

Community interactions affecting the relative abundances of native and invasive amphipods in the St. Lawrence River  

Microsoft Academic Search

The Eurasian amphipod Echinogammarus ischnus is reportedly replacing the common native amphipod Gammarus fasciatus in the Great Lakes - St. Lawrence River system. A potential mechanism for this replacement is competition mediated by resident species. Other Eurasian invaders, dreissenid mussels (Dreissena polymorpha and Dreissena bugensis), dominate rocky substrates throughout the system and might be promoting the rapid expansion of E.

M. E. Palmer; Anthony Ricciardi

2005-01-01

95

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 ...

96

Diel and lateral patterns of zooplankton distribution in the St. Lawrence River  

Microsoft Academic Search

While the four-dimensional nature of river ecosystems has been recognized for nearly two decades, the role of lateral complexity has rarely been factored into studies of zooplankton ecology. We examined the importance of hydrologic retention areas (slackwaters) near islands and embayments of the St. Lawrence River for densities, fecundity, and diel migration of planktonic microcrustaceans. Densities of cladocera and copepods

Andrew F. Casper; James H. Thorp

2007-01-01

97

Credit: Michael Anderson. NOAA Selects St. Louis River Estuary as  

E-print Network

focus on fish and wildlife habitat rehabilitation and restoration, along with identifying non estuary include: · addressing loss of fish and wildlife habitat through the funding of targeted and wildlife populatio

98

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) ...

99

Introduction The Coastal Change Analysis Project St. Croix Estuary Region CD-ROM data set  

E-print Network

by changes from the large Maine and Canadian forestry industries. Understanding where and how these changes are occurring is important for sound resource management decisions. CD-ROM Contents 1. The St. Croix Estuary. A record equals one row of pixels, and the first data record value is in the upper left-hand corner

100

ANNOTATED BIBLIOGRAPHY OF ENVIRONMENTAL RESEARCH CONDUCTED WITHIN THE ST. LOUIS RIVER ESTUARY 1903-1982  

EPA Science Inventory

This annotated bibliography reviews manuscripts and publications for content, not for results. It is thus intended as a tool for individuals attempting to locate specific types of studies conducted within the St. Louis River estuary. Each review includes the study dates, specific...

101

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...

102

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

SciTech Connect

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.

Kosatsky, T. [Montreal Public Health Program, Quebec (Canada)] [Montreal Public Health Program, Quebec (Canada); [McGill Univ., Montreal, Quebec (Canada). Dept. of Occupational Health; [Quebec Toxicology Center, Montreal, Quebec (Canada); Przybysz, R.; Shatenstein, B. [Montreal Public Health Program, Quebec (Canada)] [Montreal Public Health Program, Quebec (Canada); [McGill Univ., Montreal, Quebec (Canada). Dept. of Occupational Health; Weber, J.P. [Quebec Toxicology Center, Montreal, Quebec (Canada)] [Quebec Toxicology Center, Montreal, Quebec (Canada); Armstrong, B. [London School of Hygiene (United Kingdom)] [London School of Hygiene (United Kingdom)

1999-02-01

103

Glacial Lake Outflow via the St. Lawrence Pathway Prior to the Champlain Sea Invasion and During the Younger Dryas  

NASA Astrophysics Data System (ADS)

When the Laurentide Ice Sheet receded north of the Adirondacks, Glacial Lake Frontenac overflowed to Glacial Lake Vermont (Coveville phase)-Albany. The water level of Lake Frontenac fell by about 90 m, as a result of the drawdown, glacio-isostatic rebound and outflow of Lake Vermont-Albany through the Hudson Valley to the North Atlantic Ocean. Lake level stabilized to form the Belleville, Upper Fort-Ann, post-Sherbrooke phase of glacial lakes post-Iroquois, Vermont and Memphremagog, respectively. Initially, the confluent fresh-water body extended from the Lake Ontario basin into the upper St. Lawrence Valley, Lake Champlain basin and along the Appalachian piedmont. The outlet of the lake was the Upper Fort-Ann sill, along the Hudson pathway (Lake Albany). The expansion of the lake was time transgressive and related to the regional ice retreat. As the lake expanded across the lowlands, into the Ottawa and central St. Lawrence valleys, and along the Appalachian piedmont, its level fell by about 20 m, from the Belleville to the Trenton strandlines on the western side of the Adirondacks, and about 26 m (Rayburn, 2004) from the Upper to the Lower Fort-Ann strandlines in the Lake Champlain basin. The extent of the lake during its final stage is estimated at about 30,000 km2. Varves deposited in the deeper parts of the lake are characterized by the ostracode Candona subtriangulata. Varve counts from several reference sections provide an approximate duration for the glaciolacustrine phase in different parts of the lowlands. They range from about 50 to 30 yr in the lower Ottawa Valley, where the estimated depth was 180 to 200 m, about 100 yr along the Appalachian piedmont and, tentatively, to more than 160 yr in the Lake Champlain basin (Rayburn et al., 2005). The lake overflowed/drained suddenly to the east, toward the western arm of the Goldthwait Sea, in the Estuary and Gulf of St. Lawrence, and hence into the North Atlantic Ocean. During this event, the water level fell by about 50 to 40 m to the highest strandline of the Champlain Sea. The timing and volume of this fresh-water discharge are quantified to allow assessment of its potential impact on the thermohaline circulation of the North Atlantic Ocean, and whether it could have triggered the cold Younger Dryas episode. The overflow occurred within a one-year span between 11.2 and 10.9 14C ka BP or 13.2 and 12.85 cal ka BP, close to the onset of the Younger Dryas cold interval. The total freshwater outflow through the St. Lawrence pathway comprised the one-year overflow phase (about 1500 km3), an early mixing phase of fresh and marine waters in the Champlain Sea domain (about 400 km3 for several years), a rapid collapse of the ice margin in the lowlands during about 250 yr and, during the Younger Dryas, several outburst floods from glacial Lake Algonquin into the Champlain Sea through the middle Ottawa Valley.

Occhietti, S.; Anderson, T. W.; Karrow, P. F.; Lewis, M. C.; Mott, R. J.; Parent, M.; Richard, P. J.; Rodrigues, C. G.; Stea, R.

2005-12-01

104

North East Coast False Color Time Lapse from SeaWiFS (Gulf of St. Lawrence to Cape Cod)  

NSDL National Science Digital Library

Transitions between relatively cloud free scenes of the northeast coast from the Gulf of St. Lawrence to Cape Cod, using true color land and clouds with false color-chlorophyll water images, all from SeaWiFS

Jesse Allen

1998-09-09

105

Year-Class Formation of Upper St. Lawrence River Northern Pike  

Microsoft Academic Search

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

Brian M. Smith; John M. Farrell; H. Brian Underwood; Stephen J. Smith

2007-01-01

106

Contaminant Exposure and Biomarker Responses in Spectacled Eiders ( Somateria fischeri ) from St. Lawrence Island, Alaska  

Microsoft Academic Search

.   Effects of chemical contaminant exposure may be contributing to the decline of spectacled eiders (Somateria fischeri) nesting in coastal areas of western Alaska. We evaluated chemical exposure and potential effects in 20 male eiders collected\\u000a near St. Lawrence Island, Alaska. Analytes included metals, trace elements, chlorinated organics, and\\u000a 137Cesium (137Cs). Effects of contaminant exposure were evaluated using histopathology and

K. A. Trust; K. T. Rummel; A. M. Scheuhammer; I. L. Brisbin Jr.; M. J. Hooper

2000-01-01

107

Temporal changes in wetland landscapes of a section of the St. Lawrence River, Canada  

Microsoft Academic Search

Historical aerial photographs (from 1946 through 1983) were used to study and describe the nature and extent of changes in\\u000a wetland vegetation of a section of the St. Lawrence River and to evaluate the relative importance of water level, fire, and\\u000a vegetational development as causal factors of these historical changes. Data were encoded and analyzed using a geographical\\u000a information system,

Martin Jean; André Bouchard

1991-01-01

108

Feeding Ecology of Juvenile Lake Sturgeon in the St. Lawrence River System  

Microsoft Academic Search

We examined the diet of juvenile lake sturgeon Acipenser fulvescens at five sites in the St. Lawrence River, including two sites in major tributaries (Des Prairies and L'Assomption rivers), two main-stem sites located upstream (Verchères and Sorel-Berthier islands), and one site located downstream in the estuarine transition zone (ETZ). The benthic fauna was sampled at all sites except in the

Pedro Nilo; Serge Tremblay; Aline Bolon; Julian Dodson; Pierre Dumont; Réjean Fortin

2006-01-01

109

Impact of the( Dreissena ) invasion on native unionid bivalves in the upper St. Lawrence River  

Microsoft Academic Search

Introduced Eurasian mussels (Dreissena polymorpha and Dreissena bugensis) colonized native unionid bivalves in the upper St. Lawrence River in the early 1990s. From 1992 to 1995, we examined the infestation and impact of Dreissena on unionids at several sites near the Island of MontrØal. Unionids suffered heavy (90ñ100%) mortality at sites where Dreissena occurred in high densities (i.e., 4000 ñ

A. Ricciardi; F. G. Whoriskey; J. B. Rasmussen

1996-01-01

110

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

Microsoft Academic Search

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

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

2000-01-01

111

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

SciTech Connect

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.

Grebmeier, J.M.; Cooper, L.W. [Univ. of Tennessee, Knoxville, TN (United States)] [Univ. of Tennessee, Knoxville, TN (United States); [Oak Ridge National Lab., TN (United States)

1995-03-15

112

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

NASA Astrophysics Data System (ADS)

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.

Grebmeier, Jacqueline M.; Cooper, Lee W.

1995-03-01

113

Annual Records of Toxic phytoplankton and PSP toxins in the Gulf of St. Lawrence, Quebec.  

NSDL National Science Digital Library

This website provides access to annual records of the abundance of phytoplankton species and physical-chemical parameters of seawater at monitoring stations in the Gulf of St. Lawrence, Quebec, Canada. Users may choose a particular station and the year to view the data (which are presented in MS-Excel format, in French). The webpage also provides a link to a map displaying the locations of the sampling stations.

114

Predation on Ruffe by Native Fishes of the St. Louis River Estuary, Lake Superior, 1989–1991  

Microsoft Academic Search

The ruffe Gymnocephalus cernuus, an exotic Eurasian percid, recently became es- tablished in the St. Louis River estuary. Lake Superior, after accidental introduction. Management actions (catch regulations and stockings) were enacted in 1989 to increase the density of top-level predators in the estuary, and thus to increase predation on ruffe. We conducted a field and laboratory study to determine if.

DEREK H. OGLE; JAMES H. SELGEBY; JACQUELINE E. SAVING; RAYMOND M. NEWMAN; MARY G. HENRY

1996-01-01

115

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

PubMed Central

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

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

2014-01-01

116

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)

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.

Magnan, G.; Garneau, M.

2013-12-01

117

Supracrustal faults of the St. Lawrence rift system, Quebec: kinematics and geometry as revealed by field mapping  

E-print Network

by field mapping and marine seismic reflection data Alain Tremblay*, Bernard Long, Manon Masse´1 INRS m of basement relief. A two- way travel-time to bedrock map, based on seismic data from the St craton core to the offshore St. Lawrence River system is a seismically active zone in which fault

Long, Bernard

118

Diet and Feeding Periodicity of Ruffe in the St. Louis River Estuary, Lake Superior  

Microsoft Academic Search

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

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

1995-01-01

119

Diet and Feeding Periodicity of Ruffe in the St. Louis River Estuary, Lake Superior  

Microsoft Academic Search

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

DEREK H. OGLE; JAMES H. SELGEBY; RAYMOND M. NEWMAN; MARY G. HENRY

1995-01-01

120

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

121

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

PubMed Central

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

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

2012-01-01

122

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

PubMed

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

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

2012-01-01

123

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 ...

124

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...

125

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

USGS Publications Warehouse

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.

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

1998-01-01

126

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

USGS Publications Warehouse

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.

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

1972-01-01

127

Population Characteristics and Contaminant Burdens of the White Sucker ( Catostomus commersoni) from the St. Lawrence River near Cornwall, Ontario and Massena, New York  

Microsoft Academic Search

The objective of this study was to compare ecological and chemical characteristics of two populations of white sucker (Catostomus commersoni) (n = 762) upstream and downstream of the Moses-Saunders power dam in the St. Lawrence River. The downstream section of the St. Lawrence River near Cornwall, Ontario and Massena, New York is an International Joint Commission Area of Concern (AOC).

Lara L. Ridgway; François Chapleau; Michael E. Comba; Sean M. Backus

1999-01-01

128

Estuaries  

NSDL National Science Digital Library

An estuary is a body of water that is created when freshwater from rivers and streams flows into the saltwater of an ocean. To understand this mixing of fresh and salt water, learners go through several activities: 1) in Salt and Water, learners dissolve salt crystals in water to observe their effects on water; 2) in Making a Salt Wedge, learners make a model of a salt wedge estuary, which occurs in nature when the mouth of a river flows directly into seawater; 3) in Plant Dehydration learners observe the effects of salinity (salt content in the water) on live plants. Includes a wrap-up guide for group discussions.

2013-12-18

129

Population structure of the ribbed mussel Geukensia demissa in salt marshes in the southern Gulf of St. Lawrence, Canada  

Microsoft Academic Search

The ribbed mussel, Geukensia demissa, is highly dependent on the cordgrass Spartina alterniflora for amelioration from environmental stress and substrate stabilization. Spartina alterniflora is a foundation species in marshes, and G. demissa is typically associated with cordgrass beds. Marshes in the southern Gulf of St. Lawrence are experiencing erosion and degradation,\\u000a presumably as a result of increases in sea level,

Cortney Watt; David J. Garbary; Caroline Longtin

2011-01-01

130

?-carotene and retinoids in eggs of Great Blue Herons (Ardea herodias) in relation to St Lawrence River contamination  

Microsoft Academic Search

The potential use of retinoids and ß-carotene as biomarkers in the eggs of the Great Blue Heron was investigated. In the spring of 1991, 65 eggs were collected from nine heronries (seven along the St Lawrence River and two reference sites). A method was specifically developed for the extraction and analysis of ß-carotene and the retinoids in heron egg yolks

M. H. Boily; L. Champoux; D. H. Bourbonnais; J. L. Granges; J. Rodrigue; P. A. Spear

1994-01-01

131

Occurrence of the Odor Compounds, 2-Methylisoborneol and Geosmin in Eastern Lake Ontario and the Upper St. Lawrence River  

Microsoft Academic Search

Unpleasant tastes and odors in drinking water from the upper St. Lawrence River were investigated in the fall of 1996 and 1997 as the result of increasing taste and odor events in recent years. Taste and odor events resulted in widespread public reaction to the earthy\\/musty tasting water produced and a need for accurate information to assist water treatment efforts.

Jeffrey J. Ridal; Brian Brownlee; David R. S. Lean

1999-01-01

132

Quagga mussels ( Dreissena bugensis) as biomonitors of metal contamination: A case study in the upper St. Lawrence River  

Microsoft Academic Search

In this study, the utility of quagga mussels (Dreissena bugensis) as biomonitors was investigated by measuring total concentrations of three trace metals, cadmium, copper, and zinc, in soft tissues. Quagga mussels were sampled from five sites along the upper St. Lawrence River, including one industrially influenced site, from 1999 through 2007. Mussels were collected from near-shore areas, divided into 5

Carolyn Johns

2011-01-01

133

Spatial Distribution of Total Cadmium, Copper, and Zinc in the Zebra Mussel ( Dreissena polymorpha) Along the Upper St. Lawrence River  

Microsoft Academic Search

The zebra mussel (Dreissena polymorpha) was utilized to assess the spatial distribution of three trace metals, cadmium, copper, and zinc, in the upper St. Lawrence River and to test the hypothesis that outflow from Lake Ontario influenced levels of these metals in near-shore biota. Zebra mussels, collected from twelve sites along the southern shore, were analyzed for total cadmium, copper,

Carolyn Johns

2001-01-01

134

Development of a 3-D geological model towards natural hazards mitigation, St. Lawrence River Valley, Eastern Canada  

Microsoft Academic Search

As part of the Canadian Government's main goals to ensure safe and strong communities for its citizens, the Geological Survey of Canada has recently undertaken the development of a 3-D geological model and a seamless surficial geology map of the St. Lawrence River valley in Eastern Canada. This paper summarizes the initial phase of this project, which consists of gathering,

RÉJEAN COUTURE; DOMINIQUE GAUVREAU; J. ROBERT BÉLANGER

135

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

USGS Publications Warehouse

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)

Koester, Harry E.; Miller, Denise R.

1980-01-01

136

Effects of salinity and temperature on ex situ germination of the threatened Gulf of St. Lawrence Aster,  

E-print Network

Effects of salinity and temperature on ex situ germination of the threatened Gulf of St. Lawrence of salinity (0­20 g/L) and temperature (16­30°C) on germination of S. laurentianum seeds over 32 days. The time-course of germination was significantly affected by both salinity and temperature. At lower

Heard, Stephen B.

137

Effects of a major municipal effluent on the St. Lawrence River: A case study.  

PubMed

The St. Lawrence River (SLR) is the second largest waterway in North America. The discharge of the City of Montreal wastewater treatment plant (WWTP) represents the largest volume of treated wastewaters being released into the river. It also ranks as the largest sewage treatment plant of its kind in North America. Over the last decade, intensive multidisciplinary research has focused on assessing the impacts of Montreal wastewater effluents on the SLR. We describe the major findings of these investigations, including the determination of the fate of contaminants, bioaccumulation in fish and invertebrates, ecotoxicological measurements of aquatic animal health, evaluation of endocrine disruption, parasitism in fish, and combined effects of multiple stressors on the SLR. Impacts of the effluents from the WWTP on aquatic organisms from the SLR are both toxicological and ecological, demonstrating the need for an integrated view of the impacts of municipal effluents on aquatic ecosystems. PMID:25416865

Marcogliese, David J; Blaise, Christian; Cyr, Daniel; de Lafontaine, Yves; Fournier, Michel; Gagné, François; Gagnon, Christian; Hudon, Christiane

2015-05-01

138

January snow accumulation in the St. Lawrence Valley (1961-1990)  

NASA Astrophysics Data System (ADS)

Located in Eastern Canada, the St. Lawrence Valley (between Montreal and Quebec City; ±350 km) is known as one of the snowiest populated valleys in the world. Usually more than 250 cm of snow falls every winter. Snowstorms are frequent, as more than 10 major snowstorms are registered every year [1] interfering greatly with human activities. Numerical analyses (univariate analysis, discriminant analysis and stepwise multiple regression) for the 1961-1990 period on total snow depth for the month of January reveals three winter-regional climates along this valley: A-) the southern part of Montreal; slightly warmer with less snow and less rainfall, B-) the area around Quebec City; colder with more snow and C-) an intermediate corridor in-between those two cities. Two major variables were identified as responsible for explaining these three winter regional climates: maximum temperature and rainfall.

Toupin, Jerry

2009-09-01

139

Contaminant exposure and biomarker responses in spectacled eiders (Somateria fischeri) from St. Lawrence Island, Alaska.  

PubMed

Effects of chemical contaminant exposure may be contributing to the decline of spectacled eiders (Somateria fischeri) nesting in coastal areas of western Alaska. We evaluated chemical exposure and potential effects in 20 male eiders collected near St. Lawrence Island, Alaska. Analytes included metals, trace elements, chlorinated organics, and (137)Cesium ((137)Cs). Effects of contaminant exposure were evaluated using histopathology and biochemical measures of porphyrin profiles, cytochrome P450 activities, and metallothionein (MT) concentrations. Copper, cadmium, and selenium concentrations were elevated in spectacled eiders when compared to literature values for other marine birds. Only a few samples had trace concentrations of chlorinated organic compounds. Muscle (137)Cs levels were all below the average minimum quantifiable concentration of 0.079 Bq/g. No histopathological lesions were associated with elevated contaminant concentrations in liver, kidney, or testes. Protoporphyrin was found in highest concentration in both the liver and kidneys, followed by coproporphyrin and uroporphyrin, respectively. Hepatic uroporphyrin concentrations correlated significantly to hepatic arsenic concentrations. Mean activities of hepatic EROD, MROD, BROD, and PROD were consistent with other avian species. Comparisons of cadmium/MT ratios from this study to published literature ratios in seven marine avian species suggest that, although adult male spectacled eiders have elevated liver concentrations of certain MT-inducing metals, their MT concentrations are not as strongly induced as would be predicted based on literature values. Despite elevated metal concentrations, the apparent good health of the St. Lawrence Island birds suggests that should these contaminants be a factor in population declines, they likely act by decreasing fecundity or survival of young rather than via direct health impacts on adult male spectacled eiders. PMID:10556377

Trust, K A; Rummel, K T; Scheuhammer, A M; Brisbin, I L; Hooper, M J

2000-01-01

140

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

PubMed

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

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

2014-12-01

141

Comparative study of DNA adducts levels in white sucker fish ( Catostomus commersoni ) from the basin of the St. Lawrence River (Canada)  

Microsoft Academic Search

The levels of DNA adducts in the hepatic tissue of the white sucker fish speciesCatostomus commersoni were determined by32P-postlabelling. The fish were caught at four sites: two sites near the city of Windsor (Québec, Canada) on the St. François River, a downstream tributary of the St. Lawrence River, and two sites in the St. Lawrence River itself, near the city

C. Adlouni; J. Tremblay; P. Walsh; J. Lagueux; J. Bureau; D. Laliberte; G. Keith; D. Nadeau; G. G. Poirier

1995-01-01

142

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...

143

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...

144

Spatial and temporal variation in abundance of Diplostomum spp. in walleye ( Stizostedion vitreum ) and white suckers ( Catostomus commersoni ) from the St. Lawrence River  

Microsoft Academic Search

Abundances of eye flukes (Diplostomum spp.) were compared between walleye (Stizostedion vitreum) and white suckers (Catostomus commersoni ) collected in late summer 1997 from Lake St. Louis and Lake St. Pierre, two expansions of the St. Lawrence River in Quebec, Canada. The white sucker, a benthic consumer, was more heavily in- fected than the walleye, a pelagic piscivore, in both

David J. Marcogliese; Pierre Dumont; Andrée D. Gendron; Yves Mailhot; Emmanuelle Bergeron; J. Daniel McLaughlin

2001-01-01

145

Mo & Fe Influences on Nitrate Assimilation in Lake Ontario and the St Lawrence River  

NASA Astrophysics Data System (ADS)

Lake Ontario has undergone a steady increase in nitrate since the early 1970s, a phenomenon also occurring in other large lakes. Possible causes of this increase include rising urban and agricultural runoff, atmospheric deposition, less demand for N due to effective point source P control, and trace metal-N co-limitation as observed in Lake Erie. Despite the abundance of nitrate in Lake Ontario, heterocystous cyanobacteria have been detected here setting up the paradoxical situation wherein some cyanobacteria are investing in the more costly diazotrophy whilst surrounded by a form of N that requires less energy and metal quota to assimilate. Mo and Fe are involved in reductive nitrate assimilation making it possible that reductive nitrate assimilation in Lake Ontario is limited in phytoplankton by low trace metal bioavailability. To test this hypothesis, 1-d enrcihment experiments were conducted using trace metal clean techniques in June 2013 at two coastal sites in Lake Ontario, and 4-d enrichment experiments were conducted in July 2013 on main channel waters of the St. Lawrence River, the outflow of Lake Ontario. Water was sampled from the metalimnion of Lake Ontario and from surface water of the main channel of the river. Water was enriched with the the following treatments in triplicate: control, 100 nM KH2PO4, 50 nM FeCl3, 50 nM Na2MoO4, and a mix of P, Fe & Mo. Experiments in the river showed significant effects due to P (increase in Chl-a, NO3 and SiO2 drawdown, changes in phytoplankton community, increase in photosynthetic efficiency [Fv/Fm]) but less impact of trace metals relative to control, presumably due to greater ambient trace metal bioavailability. As measured using FluoroProbe, the phytoplankton community changed very little (over 1 d) in lake waters; there was no significant change in total chl-a. However, as in the river, Fv/Fm revealed significant metal and P effects with the P, Fe & Mo mix being significantly greater than control (Fig. 1; we will present data relating to the response of PON and POC pools to the enrichment experiments). The results suggest that P was limiting phytoplankton growth and that Mo and Fe were more co-limiting in the lake than in the river. This information builds on prior work demonstrating Fe/N co-limitation and is the first study to investigate the role of Mo in the N cycle in the Laurentian Great Lakes. Figure 1. Photosynthetic efficiency in experimental treatments measured using fast repetition rate fluorimetry after 1 d (Lake Ontario) and 4 d (St. Lawrence River); * = P < 0.05.

Twiss, M. R.; Salk, K.; Avolio, L. N.; Chappaz, A.; Ostrom, N. E.

2013-12-01

146

Mercury Partitioning in Surface Sediments of the Upper St. Lawrence River (Canada): Evidence of the Importance of the Sulphur Chemistry  

Microsoft Academic Search

An intensive survey of mercury speciation was performed at a site on the Upper St. Lawrence River near Cornwall, Ontario,\\u000a Canada with a history mercury contamination in sediments. Surface sediments were collected every 1.50 h. Total mercury (Hgtotal), methylmercury (MeHg), organic carbon, inorganic and organic sulphur were determined in the solid fraction. Dissolved Hgtotal, MeHg and dissolved organic carbon (DOC) were

João Canário; Laurier Poissant; Jeff Ridal; Tania Delongchamp; Martin Pilote; Philipe Constant; Jules Blais; David Lean

2008-01-01

147

Dioxin-Like Compounds in Fishing People from the Lower North Shore of the St. Lawrence River, Québec, Canada  

Microsoft Academic Search

In this study, investigators assessed exposure to dioxin-like compounds in a fishing population that inhabits small coastal communities along the Lower North Shore of the St. Lawrence River, Quebec. This population relies heavily on wildlife foods for sustenance. Investigators analyzed chemically the most popular marine foods (i.e., fish, crustaceans, sea mammals, and sea-bird eggs), and they also obtained 25 human

John J. Ryan; Eric Dewailly; Andy Gilman; Claire Laliberté; Pierre Ayotte; Jean Rodrigue

1997-01-01

148

Airborne transport of sulphur: Impacts on chemical composition of rivers on north shore of the St. Lawrence River (Québec)  

Microsoft Academic Search

The St. Lawrence North Shore region (Québec) is subject to acid precipitation entailing sulphate deposition (17 to 22 kg SO42- ha-1 yr-1) which poses a threat to sensitive aquatic ecosystems. Physicochemical surveys conducted in 1982–1983 revealed the extreme sensitivity of the region owing to weak mineralization of the waters (mean alkalinity of 55 µeq L-1 and conductivity of 17 µS

Marius Lachance; Denis Brouard; Gordon Walsh

1988-01-01

149

Historical changes in herbaceous wetland distribution induced by hydrological conditions in Lake Saint-Pierre (St. Lawrence River, Quebec, Canada)  

Microsoft Academic Search

Historical changes (1961–2002) in the distribution of herbaceous wetland plant associations were inferred from the hydrological regime of Lake Saint-Pierre, a 312 km2 broadening of the St. Lawrence River (Quebec, Canada), to assess the cumulative effects of human interventions and climatic variability. Relative abundance index (height × percent cover) of wetland plants in 630 field quadrats sampled at 13 sites (1999–2002)

Christiane Hudon; Pierre Gagnon; Jean-Pierre Amyot; Guy Létourneau; Martin Jean; Céline Plante; Daniel Rioux; Martin Deschênes

2005-01-01

150

Parasite fauna of Etheostoma nigrum (Percidae: Etheostomatinae) in localities of varying pollution stress in the St. Lawrence River, Quebec, Canada  

Microsoft Academic Search

Parasite communities were examined in johnny darters (Etheostoma nigrum) collected from five localities in the St. Lawrence River in southwestern Quebec: two reference localities, one polluted\\u000a locality upstream of the Island of Montreal and downstream of industrial and agricultural activity, and two polluted localities\\u000a downstream of the Island of Montreal in the plume from the wastewater treatment facility. Twenty-four helminth

Rachel J. Krause; J. Daniel McLaughlin; David J. Marcogliese

2010-01-01

151

Biomarkers in zebra mussels ( Dreissena polymorpha) for the assessment and monitoring of water quality of the St Lawrence River (Canada)  

Microsoft Academic Search

Five biomarkers (MT: metallothionein-like proteins, EROD: ethoxyresorufin ortho-dééthylase, DNA strand breaks, LPO: peroxidation of lipids, VG: vitellogenin-like protiens) were measured in the soft tissues of zebra mussels (Dreissena polymorpha) in order to assess the spatial variation of exposure to contaminants along the St Lawrence River (Canada). Fifteen mussels >25 mm shell length were analyzed from each of the 13 sampling

Yves de Lafontaine; François Gagné; Christian Blaise; Georges Costan; Pierre Gagnon; H. M. Chan

2000-01-01

152

Abundance and individual size of American eel ( Anguilla   rostrata ) in the St. Lawrence River over the past four decades  

Microsoft Academic Search

Changes in abundance indicators and the mean size of American eel (Anguilla rostrata LeSueur) in the lower St. Lawrence River (SLR) over the past 40 years were assessed to determine the chronology of the species\\u000a decline and the possible effect of hydroclimatic factors on that trend. Daily catches at commercial weirs and at an experimental\\u000a fishery were used to model the long-term

Yves de Lafontaine; Pierre Gagnon; Bernard Côté

2010-01-01

153

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

PubMed

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

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

2014-05-01

154

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

SciTech Connect

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.

Pair, D.L. (Univ. of Dayton, OH (United States). Dept. of Geology)

1993-03-01

155

Toxicity of sediments near an aluminum smelter on the St. Lawrence river to aquatic organisms  

SciTech Connect

Under a US EPA Superfund Administrative Order, over 50,000 cu yds of bottom sediments contaminated with fluoride, cyanide, PCBs, PAHs and Al will be dredged from the St. Lawrence River near the Reynolds Metals plant at Massena, NY in 1994. The purpose of this study was to determine the toxicity of these sediments to aquatic organisms and the potential for remobilizing sediment-bound contaminants into the water column during dredging. Sediment was collected from 7 sites along a gradient from the outfall in October 1993. Sediment from the most contaminated site ``B2`` (1,500 {mu}g/g fluoride, 30 {mu}g/g cyanide, 450 {mu}g/g PCBs, 3,500 {mu}g/g PAHs, 90,000 {mu}g/g Al), caused complete mortality of mayflies, Hexagenia limbata, and avoidance, considerable weight loss and some mortality in fathead minnows, Pimephales promelas, after 21 d exposure. Mortality was not observed at other sites, but growth of both organisms decreased with increasing contamination. LOECs of B2 elutriate were 13% for survival and reproduction of Ceriodaphnia dubia, and 6% for survival and 1.5% for growth of larval fatheads. Elutriates of other sediments were nontoxic. TIE testing suggested organic contaminants as the primary toxicants. Over 2,000 cu yds of sediment are highly toxic and 18,000 cu yds somewhat toxic. Toxicity of B2 elutriate shows that contaminants enter the water column when sediments are disturbed and may harm indigenous biota.

Metcalfe-Smith, J.L. [National Water Research Inst., Burlington, Ontario (Canada); Sirota, G.R.; Holtze, K.E.; Reid, J.J. [B.A.R. Environmental Inc., Guelph, Ontario (Canada)

1994-12-31

156

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

SciTech Connect

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.

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

1984-10-01

157

Recent eutrophication and consequent hypoxia in the bottom waters of the Lower St. Lawrence Estuary: Micropaleontological  

E-print Network

-2220 are strongly correlated with an increase in organic carbon (OC) content (from 1.1 to 1.6%) and to a shift in the isotopic signature of the latter (13 CORG from -24.8 to -24.0). Similarly, a concomitant decrease be observed and corresponds to dissolved oxygen concentrations below 62.5 M or 2 mg/L (Diaz and Rosenberg

Long, Bernard

158

Holocene paleomagnetic records from the St. Lawrence Estuary, eastern Canada: centennial-to millennial-scale  

E-print Network

; received in revised form 7 February 2003; accepted 10 February 2003 Abstract Two long Holocene piston cores of the expanded Holocene sediment sequence this location provides. A u-channel-based paleomagnetic study

St-Ong, Guillaume

159

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...

160

Ground-Water Quality in the St. Lawrence River Basin, New York, 2005-06  

USGS Publications Warehouse

The Federal Clean Water Act requires that States monitor and report on the quality of ground water and surface water. To satisfy part of these requirements, the U.S. Geological Survey and New York State Department of Environmental Conservation have developed a program in which ground-water quality is assessed in 2 to 3 of New York State's 14 major river basins each year. To characterize the quality of ground water in the St. Lawrence River Basin in northern New York, water samples were collected from 14 domestic and 11 production wells between August 2005 and January 2006. Eight of the wells were finished in sand and gravel and 17 wells were finished in bedrock. Ground-water samples were collected and processed using standard U.S. Geological Survey procedures and were analyzed for 229 constituents and physical properties, including inorganic constituents, nutrients, trace elements, radon-222, pesticides and pesticide degradates, volatile organic compounds, and bacteria. Sixty-six constituents were detected above laboratory reporting levels. Concentrations of most compounds at most sites were within drinking water standards established by the U.S. Environmental Protection Agency and New York State Department of Health, but a few compounds exceeded drinking water standards at some sites. Water in the basin is generally hard to very hard (hardness equal to 121 mg/L as CaCO3 or greater); hardness and alkalinity were generally higher in the St. Lawrence Valley than in the Adirondack Mountains. The cation with the highest median concentration was calcium; the anion with the highest median concentration was bicarbonate. The concentration of chloride in one sample exceeded the 250 milligrams per liter U.S. Environmental Protection Agency Secondary Drinking Water Standard; the concentration of sulfate in one sample also exceeded the 250 milligrams per liter U.S. Environmental Protection Agency Secondary Drinking Water Standard. Nitrate was the predominant nutrient detected but no sample exceeded the 10 mg/L U.S. Environmental Protection Agency Maximum Contaminant Level. The trace elements detected with the highest median concentrations were strontium, barium, and iron. Concentration of trace elements in several samples exceeded U.S. Environmental Protection Agency Secondary Drinking Water Standards, including aluminum (50 micrograms per liter, 4 samples), iron (300 micrograms per liter, 5 samples), and manganese (50 micrograms per liter, 4 samples). The concentration of uranium in one sample from a domestic well finished in crystalline bedrock was three times the U.S. Environmental Protection Agency Maximum Contaminant Level of 30 micrograms per liter. The median concentration of radon-222 was 600 picoCuries per liter, but concentrations as high as 18,800 picoCuries per liter were detected; two wells with high radon concentrations also had high uranium concentrations. Radon-222 is not currently regulated, but the U.S. Environmental Protection Agency has proposed a Maximum Contaminant Level of 300 picoCuries per liter along with an Alternative Maximum Contaminant Level of 4,000 picoCuries per liter, to be in effect in states that have programs to address radon in indoor air. Concentrations of radon-222 exceeded the proposed Maximum Contaminant Level in 60 percent of samples and exceeded the proposed Alternative Maximum Contaminant Level in 8 percent of samples. Six pesticides and pesticide degradates were detected; all were amide or triazine herbicides or degradates. Five volatile organic compounds were detected, including disinfection byproducts such as trichloromethane and gasoline components or additives such as methyl tert-butyl ether. No pesticides, pesticide degradates, or volatile organic compounds were detected above established limits. Coliform bacteria, including Escherichia coli, were detected in three wells finished in carbonate bedrock.

Nystrom, Elizabeth A.

2007-01-01

161

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)

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.

Urrego-Blanco, Jorge; Sheng, Jinyu

2014-03-01

162

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

PubMed

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

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

2012-10-15

163

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

NASA Astrophysics Data System (ADS)

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.

Pillay, D.; Perissinotto, R.

2008-03-01

164

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

USGS Publications Warehouse

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 the 4,654-ha St. Louis River estuary in May-October 1989-1990 and the feeding periodicity of ruffes in two adjacent habitats during 5 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.

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

1995-01-01

165

Index of surface-water records, part 4, St. Lawrence River Basin, to September 30, 1950  

USGS Publications Warehouse

The index lists the stream-flow and reservoir stations in the St. Lawrence River Basin for which records have been or are to be published for periods prior to September 30, 1950. The stations are listed in downstream order. Tributary streams are indicated by indention. Station names are given in their most recently published forms. Parentheses around part of a station name indicate that the inclosed word or words were used in an earlier published name or the station or in a name under which records were published by same agency other than the Geological Survey. The drainage areas, in square miles, are the latest figures published or otherwise available at this time. Drainage areas that were obviously inconsistent with other drainage areas on the same stream have been omitted. Some drainage areas not published by the Geological Survey are listed with an appropriate footnote stating the published source or the figure or drainage area. Under "period of record" breaks of less than a 12-month period are not shown. A dash not followed immediately by a closing date shows that the station was in operation on September 30, 1950. The years given are calendar years. Periods of records published by agencies other than the Geological Survey are listed in parentheses only when they contain more detailed information or are for periods not reported in publications to the Geological Survey. Records both of gage height and of discharge are listed for stream-flow stations, and records of gage height and of contents (or of change in contents) are listed for stations on reservoirs. Records of gage heights only and records consisting only of monthly figures either of stream flow or reservoir contents are designated by symbols and footnotes. For early years when daily discharges were not generally published by the Geological Survey, published daily gage heights and a published rating table are considered to be equivalent to daily discharges. An alphabetical index of streams. canals. and reservoirs is given on pages 12 to 14.

U.S. Geological Survey

1951-01-01

166

Crustal Structure Beneath the Gulf of ST. Lawrence, Atlantic Canada, from Ambient Seismic Noise Tomography  

NASA Astrophysics Data System (ADS)

The Gulf of St. Lawrence (GSL), located north of the southwest-northeast trending Appalachian mountain in eastern Canada, is a major sedimentary basin with huge potentials for hydrocarbon accumulation. Important questions about the geometry and evolution of the crustal and basin structure beneath the gulf are yet to be answered. To address these issues, the Geological Survey of Canada (GSC) with support from the Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity (POLARIS) deployed a temporary array of broadband seismic stations in the GSL region between October 2005 and October 2008. Combined with the permanent stations of the Canadian National Seismograph Network (CNSN) in the region, the station density is sufficient for detailed seismic tomography inversion. In this study, we investigate the upper crustal structure beneath the gulf using 3 years of continuous ambient noise waveforms recorded at 25 (POLARIS and CNSN) stations around the GSL. Cross-correlation functions of the vertical component of the ambient noise wavefield for simultaneously recording station pairs (corresponding to inter-station Green's functions) are computed and analyzed using the frequency-time analysis method. Dispersion curves are measured and Rayleigh wave group velocities are subsequently extracted for periods between 2 and 20s, which are periods sensitive to the upper crustal structures. Preliminary results from the dispersion measurements indicate that mean group velocities in the region range from 2.8 to 3.2 km/s across the range of period specified. 2-D group velocity distribution for each period is determined by linearized inversion of the dispersion data. Our tomography results show prominent lateral velocity variation. Low velocity anomalies are observed at shorter periods (up to ~10 s) which correspond to the sedimentary structures at shallow depths (between 5-10 km), whereas the characteristics of upper crustal structures are shown by velocity anomalies at longer periods. Our results show striking similarities with the tomographic images obtained in the previous Canada-wide ambient noise analysis for areas where both studies overlap and are also consistent with results from receiver function and active seismic profiling studies previously done in the region. A detailed inversion of the 3-D shear velocity structure will be conducted to appropriately delineate the thickness and seismic velocity of the composite geologic units.

Kuponiyi, A.; Kao, H.; Cassidy, J. F.; Spence, G.

2013-12-01

167

Comparative study of DNA adducts levels in white sucker fish (Catostomus commersoni) from the basin of the St. Lawrence River (Canada).  

PubMed

The levels of DNA adducts in the hepatic tissue of the white sucker fish species Catostomus commersoni were determined by 32P-postlabelling. The fish were caught at four sites: two sites near the city of Windsor (Québec, Canada) on the St. François River, a downstream tributary of the St. Lawrence River, and two sites in the St. Lawrence River itself, near the city of Montréal (Québec, Canada). The latter sites are known to be contaminated by many pollutants including polycyclic aromatic hydrocarbons. Total adduct levels in all fish ranged from 25.1-178.0 adducts per 10(9) nucleotides. White sucker from the selected sites of the St. Lawrence River had a significantly higher mean level of DNA adducts than those of the St. François River (129.4 vs 56.8, respectively). These results suggest that the effluents of many heavy industries (e.g. from a Soderberg aluminium plant) flowing in the St. Lawrence River are more likely to produce genotoxic damage to fish than those released in one of its tributary, and mainly associated to the activities of a small town and a nearby pulp and paper mill. PMID:8594417

el Adlouni, C; Tremblay, J; Walsh, P; Lagueux, J; Bureau, J; Laliberte, D; Keith, G; Nadeau, D; Poirier, G G

1995-07-19

168

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

PubMed

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: 5.07±4.72ng/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

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

2013-08-01

169

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

PubMed

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

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

2014-01-01

170

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

PubMed Central

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

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

2014-01-01

171

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

USGS Publications Warehouse

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.

Brown, C. Ervin

1978-01-01

172

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

USGS Publications Warehouse

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.

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

2006-01-01

173

Microalgal productivity in an estuarine lake during a drought cycle: The St. Lucia Estuary, South Africa  

NASA Astrophysics Data System (ADS)

The St. Lucia estuarine lake on the north coast of KwaZulu-Natal, South Africa, is one of the largest estuarine systems in Africa and of unique importance for the adjacent marine and terrestrial ecosystems. The area regularly experiences periods of drought, resulting in hypersaline conditions in its shallow lakes and the closure of the estuarine mouth. This study aimed to assess the primary production rates of phytoplankton and microphytobenthos throughout an annual cycle of this drought phase. Primary production rates were assessed at representative sites, namely the Mouth, Narrows, South and North Lakes from June 2006 to May 2007. Because of the drought, the salinity gradient from the mouth to the head of the estuary was reversed by comparison to estuarine systems with a steady freshwater inflow and regular marine exchange. In March 2007, during the study, the mouth opened as a result of rough seas, and the marine influence broke the existing reversed gradient, producing a marine salinity throughout the system. Microphytobenthic primary productivity varied between 0 and 34 mg C m -2 h -1 and showed strong correlations with salinity, DIN:DIP ratios and irradiance. Benthic productivity was high across the system after breaching of the mouth. Pelagic primary productivity (between 0 and 180 mg C m -2 h -1), showed a correlation with temperature and irradiance and was highest across the system in February 2007 when the mouth was still closed. There was no significant correlation between production rates and biomass (chl-a) in either the benthic or pelagic habitats. The negative correlation between DIN:DIP ratio and benthic primary productivity indicated that phosphorus was the limiting nutrient. This study shows that salinity, along with seasonally dependent parameters such as temperature and irradiance, correlates with the rate of microalgal production. Hence, in these shallow lakes, the largest primary productivity can occur in either the pelagic or benthic subsystems, depending on prevailing conditions at the time.

van der Molen, Johan S.; Perissinotto, Renzo

2011-03-01

174

Development of a Halotolerant Community in the St. Lucia Estuary (South Africa) during a Hypersaline Phase  

PubMed Central

Background The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. Methodology/Principal Findings This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity. Conclusions/Significance Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the physiological thresholds of this community, as well as other unique biodiversity components which this system sustains. PMID:22238676

Carrasco, Nicola K.; Perissinotto, Renzo

2012-01-01

175

Genetic Divergence among Northern Pike from Spawning Locations in the Upper St. Lawrence River  

Microsoft Academic Search

To assess the ecological consequences associated with the degradation of riparian wetlands that historically provided spawning and rearing habitat for northern pike Esox lucius, annual spawning migrations and genetic structure were used to examine this species' dependence on four specific spawning areas in the Thousand Islands region of the Saint Lawrence River. Tagging and recapture over three consecutive spawning seasons

Aaron Bosworth; John M. Farrell

2006-01-01

176

ASSESSMENT OF WATER QUALITY USING EPIPHYTIC DIATOM ASSEMBLAGES ON CLADOPHORA FROM THE ST. LAWRENCE RIVER (CANADA)  

Microsoft Academic Search

Diatoms epiphytic on Cladophora were examined from 36 sites in the Saint Lawrence River between Salaberry-de-Valleyfield and Ile d'Orleans (Quábec, Canada). A total of 129 diatom taxa were identified from Cladophora in June 1995, and of these, 34 species were present at a relative abundance ? 1% at three or more sites. The four most abundant taxa were Cocconeis pediculus,

Jacqueline M. OConnell; Euan D. Reavie; John P. Smol

1997-01-01

177

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 ...

178

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

Microsoft Academic Search

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

Alice Hontela; D. Duclos; R. Fortin; P. Dumont

1995-01-01

179

Distribution and community structure of the benthic fauna of the north shore of the Gulf of St. Lawrence described by numerical methods of classification and ordination  

Microsoft Academic Search

The invertebrate benthic macrofauna of the northern part of the Gulf of St. Lawrence was sampled with a van Veen grab along a series of transects from 37 to 285 m in May, 1981. The pattern of spatial distribution was determined by classification and ordinastion techniques and by diversity and evenness statistics. Classification and ordination resulted in eleven station groups

B. Long; J. B. Lewis

1987-01-01

180

Growth and Sexual Maturation of the American Sand Lance (Ammodytes americanus Dekay) off the North Shore of the Gulf of St. Lawrence  

Microsoft Academic Search

Samples of American sand lance (Ammodytes americanus) were collected in June­ September 1983 off the north shore of the Gulf of St. Lawrence, at depths varying from 1 to 40 m. Length-frequency modes identified by modal analysis corresponded closely with mean lengths of fish based on otolith annuli counts, supporting the hypothesis that the number of annuli corres­ ponds to

Jean-Claude F. Brethes; Roger Saint-Pierre; Gaston Desrosiers

181

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  

Microsoft Academic Search

Signs of decreasing landings and recruitment have been observed during the last decade in American eels (Anguilla rostrata) from the St. Lawrence River basin, Canada. A study was undertaken to examine whether important manifestational diseases among commercial catches could be associated with these declines. During this survey, 56 fishermen from Lakes Ontario, Saint-François and Saint-Pierre, the Richelieu River, the Québec

Lucie Dutil; Denise Bélanger; Catherine M Couillard

1997-01-01

182

A processing plant survey of external lesions of American eels ( Anguilla rostrata) from Lake Ontario and the St. Lawrence River, Canada  

Microsoft Academic Search

Signs of decreasing landing and recruitment were observed in the last decade in American eels (Anguilla rostrata) from the St. Lawrence River basin, Canada. In order to verify if the declines were associated with high prevalence of diseases among commercial catches, a total of 12243 eels captured in five commercial fishing sites were inspected at two processing plants in 1992.

Lucie T Dutil; Catherine M Couillard; Denise Bélanger

1997-01-01

183

Contrasting shell\\/tissue characteristics of Dreissena polymorpha and Dreissena bugensis in relation to environmental heterogeneity in the St. Lawrence River  

Microsoft Academic Search

The zebra mussel, Dreissena polymorpha, is widespread in the St. Lawrence River while the conspecific quagga mussel, Dreissena bugensis, is found only in the Lake Ontario outflow region of the river. This situation provided an opportunity to evaluate in situ environmental and interspecific heterogeneity in shell and tissue growth. Shell dry weight, carbon content, and shell strength of D. polymorpha

Andrew F. Casper; Ladd E. Johnson

2010-01-01

184

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  

Microsoft Academic Search

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

Christine A. Bishop; Margie D. Koster; Andrew A. Chek; David J. T. Hussell; Ken Jock

1995-01-01

185

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

186

Comparison of the interannual variability of spring heavy floods characteristics of tributaries of the St. Lawrence River in Quebec (Canada)  

NASA Astrophysics Data System (ADS)

Comparison of the interannual variability of five characteristics (magnitude, duration, timing, frequency, and variability) of spring heavy floods was carried out for 17 natural rivers in Quebec for the period from 1934 to 2004 to detect any effect of climate warming on these characteristics. This was done using the Lombard method and Copula. Changes in the mean and variance of all characteristics of streamflow were observed, and all these changes are abrupt. Whereas little significant change was observed in the magnitude, duration and variability (CV) series of spring flood flows. A significant change was noted in the frequency (diminution) for five rivers and in the timing of spring floods for six rivers. However, the change in mean timing is the only one that has a hydroclimatic significance in time and space. This change was observed, on the one hand, in the Eastern hydrological region, located on the south shore of the St. Lawrence River, north of 47°N, and characterized by a maritime climate and, on the other hand, in the South-west hydrological region, located on the north shore and characterized by a continental climate. In both cases, the change took place after the second half of the 1970s and is characterized by the early occurrence of spring floods. In addition, in both hydrological regions, the timing of spring floods is correlated with the same hydroclimatic indices, showing a positive correlation with the North Atlantic Oscillation (NAO) and a negative correlation with the Atlantic Multidecadal Oscillation (AMO). Frequency is the only characteristic for which mean and variance changed significantly over time for the same rivers (4), all located north of 48°N, on both shores of the St. Lawrence. For all flow characteristics, the change in variance can predate, postdate or be synchronous with the change in mean. Finally, the dependence between the various characteristics of spring floods as determined using the Kendall tau statistic remained constant in time for most of the rivers.

Mazouz, Rabah; Assani, Ali A.; Quessy, Jean-François; Légaré, Guillaume

2012-01-01

187

Description of Gyrodactylus mediotorus n. sp. (Monogenea: Gyrodactylidae) infecting spottail shiner (Notropis hudsonius) from the St. Lawrence River, Canada.  

PubMed

Gyrodactylus mediotorus n. sp. is described from the body, fins, and buccal cavity of the spottail shiner, Notropis hudsonius (Cyprinidae) from the St. Lawrence River, Quebec, Canada. Gyrodactylus mediotorus n. sp. is the first species of Gyrodactylus Nordmann, 1832 described from N. hudsonius and is characterized by large hamuli, large medial process of the ventral bar, narrow linguiform ventral bar membrane, large anterolateral processes, and marginal hooks with long shafts and distinctly shaped sickle. The species that most resembles Gyrodactylus mediotorus n. sp. is Gyrodactylus protuberus Rogers and Wellborn, 1965 described from the stargazing shiner, Notropis uranoscopus Suttkus, 1959. The 2 species can be differentiated based on the larger hamuli (68.4 vs. 64) and ventral bar (38.4 vs. 24) of Gyrodactylus mediotorus n. sp. and the shape of the marginal hooks which for Gyrodactylus mediotorus n. sp. has a slightly larger toe and a point which is not as angled. The morphological description is supplemented with 436 sequenced base pairs of the 18S gene (including the V4 region) as well as 1,041 sequenced base pairs spanning the complete ITS-1, 5.8S, and ITS-2 regions. BLAST (Basic Local Alignment Search Tool) searches failed to provide any close matches for either regions of DNA, with Gyrodactylus colemanensis infecting Salvelinus fontinalis being the most genetically similar for both the 18S (?91%, JF836090) and ITS (?84%, JF836142) rDNA regions. Gyrodactylus mediotorus n. sp. has been found infecting spottail shiners in the St. Lawrence River in low prevalence and intensities periodically over the last 15 yr. PMID:23883192

King, Stanley D; Marcogliese, David J; Forest, Jonathon J H; McLaughlin, J Daniel; Bentzen, Paul

2013-12-01

188

Plankton ecosystem response to freshwater-associated bulk turbidity in the subarctic Gulf of St. Lawrence (Canada): A modelling study  

NASA Astrophysics Data System (ADS)

We present a three-dimensional physical-biological modelling study aiming to infer the effect of freshwater-associated bulk turbidity on the Gulf of St. Lawrence (Canada) plankton ecosystem. Bulk turbidity is parameterised using an inverse relationship derived from an extensive in situ dataset linking salinity to the diffuse attenuation coefficient of photosynthetically available radiation (PAR) due to nonchlorophyllous matter. Embedding bulk turbidity in the model led to shallowing of the photic zone in the estuarine plume in accordance with coincident observations and allowed a better discrimination between Case 1 (chlorophyll-mediated variability of the photosynthetic available radiation attenuation) and Case 2 waters. The spring bloom was delayed, and primary and secondary production rates as well as the export of biogenic matter at depth decreased in the freshwater-influenced subregions. Comparisons with literature and coincident in situ measurements showed that nitrates were over- and underestimated in the run with and without bulk turbidity, respectively. A sensitivity analysis was performed with a relatively simple but robust parameterisation of photoacclimation, i.e. the adjustment of the phytoplankton photosynthetic efficiency to local underwater light conditions. Photoacclimation allowed simulated chlorophyll and nitrate concentrations as well as lateral fluxes of nitrate to achieve the best agreement with coincident measurements and literature estimates, respectively. This study showed that accounting for the freshwater-associated bio-optical variability and phytoplankton response in terms of photosynthetic efficiency improved the model's ability to predict the plankton ecosystem dynamics and associated biogeochemical fluxes in the river-influenced Gulf of St. Lawrence.

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

2010-04-01

189

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

PubMed

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

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

2014-05-01

190

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

SciTech Connect

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.

Flipo, D.; Fournier, M. [Univ. du Quebec, Montreal, Quebec (Canada); Beaulieu, C.; Tessier, C. [McGill Univ., Montreal, Quebec (Canada)

1995-12-31

191

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

NASA Astrophysics Data System (ADS)

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 (?2H and ?18O) 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.

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

2010-12-01

192

Recent climatic trends in nearshore water temperatures in the St. Lawrence Great Lakes  

Microsoft Academic Search

In the Great Lakes region, the observational evidence for climatic change has been primarily limited to changes in lake-ice conditions, with no long-term trends identified in water temperatures. Seven nearshore water intake sites (Bay City, Michigan; Green Bay, Wisconsin; Sault Ste. Marie, Michigan; St. Joseph, Michigan; Sandusky Bay, Ohio; Put-In-Bay, Ohio; and Erie, Pennsylvania) in the Great Lakes were chosen,

Michael J. McCormick; Gary L. Fahnenstiel

1999-01-01

193

Fish community changes in the St. Louis River estuary, Lake Superior, 1989-1996: Is it ruffe or population dynamics?  

USGS Publications Warehouse

Ruffe (Gymnocephalus cernuus) have been implicated in density declines of native species through egg predation and competition for food in some European waters where they were introduced. Density estimates for ruffe and principal native fishes in the St. Louis River estuary (western Lake Superior) were developed for 1989 to 1996 to measure changes in the fish community in response to an unintentional introduction of ruffe. During the study, ruffe density increased and the densities of several native species decreased. The reductions of native stocks to the natural population dynamics of the same species from Chequamegon Bay, Lake Superior (an area with very few ruffe) were developed, where there was a 24-year record of density. Using these data, short- and long-term variations in catch and correlations among species within years were compared, and species-specific distributions were developed of observed trends in abundance of native fishes in Chequamegon Bay indexed by the slopes of densities across years. From these distributions and our observed trend-line slopes from the St. Louis River, probabilities of measuring negative change at the magnitude observed in the St. Louis River were estimated. Compared with trends in Chequamegon Bay, there was a high probability of obtaining the negative slopes measured for most species, which suggests natural population dynamics could explain, the declines rather than interactions with ruffe. Variable recruitment, which was not related to ruffe density, and associated density-dependent changes in mortality likely were responsible for density declines of native species.

Bronte, Charles R.; Evrard, Lori M.; Brown, William P.; Mayo, Kathleen R.; Edwards, Andrew J.

1998-01-01

194

Variations in water temperatures and levels in the St. Lawrence River (Québec, Canada) and potential implications for three common fish species  

Microsoft Academic Search

The implications for fish populations of long- (multi-decadal, 1919–2007), medium- (inter-annual) and short- (seasonal, daily)\\u000a term variations in water temperatures and levels were examined in the St. Lawrence River (SLR). The effects of the seasonal\\u000a thermal regime of the SLR and its tributaries on the thermal budgets of resident and migrating fish were contrasted. Over\\u000a the 1919–2007 period, the mean

Christiane Hudon; Alain Armellin; Pierre Gagnon; Alain Patoine

2010-01-01

195

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

Microsoft Academic Search

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

P. Richard; S. Occhietti

2004-01-01

196

Invasive species are less parasitized than native competitors, but for how long? The case of the round goby in the Great Lakes-St. Lawrence Basin  

Microsoft Academic Search

There is increasing evidence that parasitism represents an unpredictable dimension of the ecological impacts of biological\\u000a invasions. In addition to the risk of exotic pathogen transmission, other mechanisms such as parasite-release, could contribute\\u000a to shaping the relationship between introduced species and native communities. In this study, we used the Eurasian round goby\\u000a (Neogobius menalostomus) in the Great Lakes-St. Lawrence River

Andrée D. Gendron; David J. Marcogliese; Michael Thomas

197

Spatial and Temporal Trends of Mercury Concentrations in Young-of-the-Year Spottail Shiners ( Notropis hudsonius ) in the St. Lawrence River at Cornwall, ON  

Microsoft Academic Search

The St. Lawrence River at Cornwall, Ontario is an “Area of Concern” because of mercury (Hg) biomagnification from bottom sediments.\\u000a To assess the spatial and temporal distribution of Hg in the food web, young-of-the-year (YOY) spottail shiners (Notropis hudsonius) were collected in August 2005 from five sites along the Cornwall waterfront within a Hg-contaminated zone and two reference\\u000a zones. The

Emily S. Choy; Peter V. Hodson; Linda M. Campbell; Adrienne R. Fowlie; Jeff Ridal

2008-01-01

198

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  

Microsoft Academic Search

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

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

2004-01-01

199

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

PubMed

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

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

1998-04-01

200

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

PubMed

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

Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

2008-06-01

201

?-carotene and retinoids in eggs of Great Blue Herons (Ardea herodias) in relation to St Lawrence River contamination.  

PubMed

: The potential use of retinoids and ?-carotene as biomarkers in the eggs of the Great Blue Heron was investigated. In the spring of 1991, 65 eggs were collected from nine heronries (seven along the St Lawrence River and two reference sites). A method was specifically developed for the extraction and analysis of ?-carotene and the retinoids in heron egg yolks by reversed-phase HPLC. When results were expressed either as the molar ratio of retinol: retinyl palmitate or as retinyl palmitate concentration, significant differences were found between colonies; however, retinyl palmitate concentration was deemed the better biomarker because it was not significantly influenced by embryonic stage of development. Retinyl palmitate concentrations in freshwater colonies were negatively related to PCB congeners Nos 105 and 118 as well as their TCDD-EQ values (p < 0.02, r (2)=0.78). Egg tetrachloro-mono-ortho biphenyl concentrations were also negatively related to retinyl palmitate (p < 0.005, r (2)=0.90). With the exception of the two mono-ortho co-planar congeners detected in the present study, the contamination levels found in heron eggs were well below those found for other bird species in the Great Lakes area and, so far, no detrimental effects have been reported in Great Blue Heron populations in Quebec. These results suggest that retinyl palmitate may be useful as a sensitive and non-invasive biomarker for monitoring organochlorine contaminant effects in the Great Blue Heron in freshwater sites. PMID:24202125

Boily, M H; Champoux, L; Bourbonnais, D H; Des Granges, J L; Rodrigue, J; Spear, P A

1994-12-01

202

Myxozoan communities parasitizing Notropis hudsonius (Cyprinidae) at selected localities on the St. Lawrence River, Quebec: possible effects of urban effluents.  

PubMed

Late summer myxozoan infra- and component communities parasitizing 73 Notropis hudsonius at 5 sites on the St. Lawrence River upstream and downstream from the island of Montreal are described from study of histological sections of individual fish. Community membership included Myxobolus sp. A (intracellular in striated muscle fibers), Myxobolus sp. B (intracellular in striated muscle fibers), Myxobolus sp. C (brain), and Thelohanellus notatus (Mavor, 1916) Kudo, 1929 (loose connective tissue), all of which are histozoic myxobolids displaying strict tissue specificity for trophozoite development. Mean infracommunity richness in fish at the separate localities was estimated to be 0.4 +/- 0.5 to 1.3 +/- 0.7, with a maximum richness of 3 in any 1 fish. Component community richness in host samples was 2 to 4. It is argued that these are relatively high levels of diversity for freshwater fish parasites but that the values are probably conservative because of the study of only portions of individual fish. The percentage of fish infected with myxozoans of any species and infracommunity richness was significantly greater below the island of Montreal compared with above it. It is suspected that increased oligochaete populations at these sites, resulting from sewage-caused organic enrichment of sediments, may have accounted for the observed increased prevalence of infection. PMID:11695414

Marcogliese, D J; Cone, D K

2001-10-01

203

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

SciTech Connect

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.

Bishop, C. [Canadian Wildlife Service, Burlington, Ontario (Canada); Trudeau, S.; Kennedy, S.; Norstrom, R. [National Wildlife Research Centre, Hull, Quebec (Canada); Stegeman, J. [Woods Hole Oceanographic Institution, MA (United States)

1995-12-31

204

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

PubMed

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

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

2012-07-01

205

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

USGS Publications Warehouse

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)

Snavely, D.S.

1988-01-01

206

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

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 (?(15)N)/carbon-13 (?(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

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

2014-11-01

207

Comparing pristine and depleted ecosystems: The Sørfjord, Norway versus the Gulf of St. Lawrence, Canada. Effects of intense fisheries on marine ecosystems  

NASA Astrophysics Data System (ADS)

The Sørfjord, Norway, and the Gulf of St. Lawrence, Canada, are two sub-arctic ecosystems with similar trophic structure. However, in the Gulf of St. Lawrence, severe exploitation of groundfish stocks has lead to important shifts in the trophic structure. In the Sørfjord, the situation is different: fishing pressure is much lighter. Our hypothesis is that overexploitation leads to changes in the trophic structure and severely alters the resilience of ecosystems. Based on the same modelling approach ( Ecopath with Ecosim) the food web structure was compared, using different ecosystem indicators. Patterns of food web structure and trophodynamics were contrasted. Cod was the keystone species in both ecosystems, and forage fish were also important. Even after similar environmental changes in both ecosystems, and after a reduction of fishing pressure in the Gulf of St. Lawrence, there is no recovery of cod stocks in this ecosystem. In the Sørfjord, after different perturbations (but not from the fishery), the ecosystem seems to return to its equilibrium.

Morissette, Lyne; Pedersen, Torstein; Nilsen, Marianne

2009-04-01

208

Exploratory assessment of fish consumption among Asian-origin sportfishers on the St. Lawrence river in the montreal region.  

PubMed

An exploratory survey was undertaken in the fall 1995 open-water fishing season with nine Bangladeshi and nine Vietnamese-origin sportfishers. Survey methodology and techniques of dietary and fish intake assessment were adapted to the cultural values and second language of each community. A 70-item instrument assessing sportfishing practices and fish consumption habits was administered by dietitians in participants' homes. Two 24-h diet recalls (aided by photographs taken by the participants) and a fish consumption calendar permitted the assessment of fish intake in the overall dietary context. A fish frequency item addressed consumption of locally available fish species (both sport and market fish) as well as imported frozen or dried species. Annually, Bangladeshi fishers consumed 46.8+/-25.6 sportfish meals, and Vietnamese fishers ate 40. 7+/-35.1 meals. In contrast, Bangladeshis reported greater annual consumption of imported, frozen nonsportfish (76.0+/-40.9 meals), and the Vietnamese ate more ocean than freshwater fish (45.1+/-34.4 ocean fish meals). Fish constituted approximately 19% of all protein foods eaten among the Bangladeshi fishers and 10% in the Vietnamese sample. Plasma and erythrocyte eicosapentanoic acid (EPA):arachidonic acid (AA) ratios supported findings from the fish frequency question showing that the two groups of Asian-origin fishers eat differing quantities of different fish species and that Asian-origin sportfishers-particularly the Bangladeshis-eat fish overall more frequently and in greater variety and quantity than francophone Quebecers; species selection appears to be both culturally motivated and influenced by the availability of St. Lawrence sportfish. PMID:10092420

Shatenstein, B; Kosatsky, T; Tapia, M; Nadon, S; Leclerc, B S

1999-02-01

209

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)

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.

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

2013-12-01

210

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

SciTech Connect

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.

Rousseaux, C.G. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)]|[GlobalTox International Consultants, Inc., Ottawa, Ontario (Canada)]|[Univ. of Quebec, Montreal, Quebec (Canada); Branchaud, A.; Spear, P.A. [Univ. of Quebec, Montreal, Quebec (Canada)

1995-05-01

211

(222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.  

PubMed

One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. PMID:24973780

Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

2014-10-01

212

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

USGS Publications Warehouse

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.

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

2004-01-01

213

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

PubMed

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

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

2004-08-01

214

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)

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.

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

2006-05-01

215

Effects of progressive oxygen depletion on sediment diagenesis and fluxes: A model for the lower St. Lawrence River Estuary  

E-print Network

and anaer- obic metabolisms, and it reflects the balance between supply and consumption of oxygen in several modeling studies (Soetaert et al. 1996; Berg et al. 2003; Morse and Eldridge 2007). In contrast the sediment column. Decadal-scale shifts in the OPD can also take place in fjords, landlocked basins

Long, Bernard

216

Chemical Risks Associated with Consumption of Shellfish Harvested on the North Shore of the St. Lawrence River's Lower Estuary  

Microsoft Academic Search

In addition, we analyzed samples of shellfish harvested in this area to determine the nature and levels of the chemical contamination. We also aimed to assess the cancer and noncancer risks associated with consumption of shellfish harvested in this area. Shellfish have the capacity to accumulate chemical contaminants found in their biotope and there- fore present a potential risk for

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

2004-01-01

217

Macrofossil Record of a Middle Holocene Drop in Relative Sea Level at the St. Lawrence Estuary, Québec  

NASA Astrophysics Data System (ADS)

Macrofossil analysis of a peat layer overlying shallow-water estuarine sediments allows the reconstruction of vegetation changes between 7000 and 6000 14C yr B.P. near Montmagny, Québec. About 7500-7000 14C yr B.P., the study site was brackish and intertidal. Next, a cattail marsh dominated by Typha changed into a terrestrial fire-prone environment that contained xero-mesophilous tree species (Pinus/Tsuga) and lasted a few hundred years, until about 6800 14C yr B.P. This rapid change may have resulted from land tilting associated with the northward migration of the postglacial forebulge. An abrupt change from a Pinus/Tsuga-dominated cover to shrubby vegetation was due to a fire that affected the site 6800 14C yr B.P. Fossil mosses at the site reflect local wetness likely produced by a rise in the water table starting about 6600 14C yr B.P. By 6500-6400 14C yr B.P., seawater returned and freshwater plants were replaced by semihalophilous and halophilous plants. Thinning of annual rings in fossil larch reflects this change from a terrestrial peatland to a treeless coast.

Bhiry, Najat; Garneau, Michelle; Filion, Louise

2000-09-01

218

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

Code of Federal Regulations, 2014 CFR

...Lawrence River and 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 §...

2014-10-01

219

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

Code of Federal Regulations, 2013 CFR

...Lawrence River and 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 §...

2013-10-01

220

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

PubMed Central

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

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

221

A comparison of biofilms from macrophytes and rocks for taste and odour producers in the St. Lawrence river.  

PubMed

Given their widespread and prolific annual development in the St. Lawrence River (SLR), macrophytes (i.e. submerged aquatic plants) represent large surface areas for biofilm growth and potentially important sites for associated production of taste and odour (T&O) compounds. We therefore evaluated the importance of submerged macrophytes and their associated biofilms for production of T&O compounds, 2-methylisoborneol (MIB) and geosmin (GM), compared with biofilms from adjacent rocks. We also tested the hypothesis that production of these compounds would differ between macrophyte species, based on the premise that they are not inert substrates but directly influence the communities that colonise their surfaces. Samples collected from transects across the SLR between Kingston and Cornwall, ON were dominated by the flat-bladed Vallisneria spp., and the leafed Myriophyllum spicatum, Elodea canadensis, Chara spp., Potamgeton spp., and Ceratophyllum spp. Overall, MIB and GM levels in biofilms ranged widely between samples. Expressed per g dry weight of biofilm, median levels from macrophyte were 50 (range 1-5000) ng MIB g(-1) and 10 (<1 to 580) ng GM g(-1) compared with 50 (range 5-970) ng MIB g(-1) and 160 (1-1600) ng GM g(-1) from rocks. Based on non-parametric statistical analysis, levels of GM were higher on a g dry weight basis in biofilms from rocks than macrophytes (P = 0.02), but MIB levels were similar (P = 0.94). However, when normalised for differences in substrate surface area (i.e. ng cm(-2)), levels of both MIB and GM were higher in biofilms from rocks than from macrophytes (P < 0.01). There were no discernable differences in MIB and GM concentrations from biofilms of different macrophytes based on either g dry weight sample or surface area (P > 0.05). Overlying water (OLW) concentrations ranged between 2-45 ng L(-1) for MIB and 5-30 ng L(-1) for GM and were not correlated with levels in adjacent biofilms. However, OLW concentrations peaked in shallow, low energy embayments consistent with enhanced production and release of MIB and GM in nearshore areas. The results support our previous work showing the importance of biofilms on various surfaces (rocks, macrophytes and zebra mussels) for MIB and GM production in the SLR, but suggest that inert surfaces like rocks are more productive sites per unit surface area than macrophytes. PMID:17489389

Ridal, J J; Watson, S B; Hickey, M B C

2007-01-01

222

St. Lawrence Cattaraugus  

E-print Network

Richburg Angelica Wellsville Canaseraga Oil Springs Scio Wirt Allen Alma Cuba Hume Amity Almond Belfast Grove Bolivar Willing Ward Alfred Birdsall Burns Andover Angelica Genesee Rushford Wellsville Granger

Keinan, Alon

223

Predation on ruffe by native fishes of the St. Louis River Estuary, Lake Superior, 1989-1991  

USGS Publications Warehouse

The ruffe Gymnocephalus cernuus, an exotic Eurasian percid, recently became established in the St. Louis River estuary, Lake Superior, after accidental introduction. Management action (catch regulations and stocking) were enacted in 1989 to increase the density of top-level predators in the estuary, and thus to increase predation on ruffe. We conducted a field and laboratory study to determine if, and to what extent, native piscivores consume ruffe. Stomachs of 3,669 predators were examined in 1989-1991. Ruffe occurred in 6.7% of burbot Lota lota, 5.8% of bullheads Ictalurus spp., 4.7% of smallmouth bass Micropterus dolomieu, 2.6% of northern pike Esox lucius, 2.6% of black crappies Pomoxis nigromaculatus, and 1.3% of yellow perch Perca flavescens (4.5% after 1989) captured during the 3-year study. No ruffe were found in 967 stomachs of walleyes Stizostedion vitreum examined. Ruffe were 22.7% of the diet (by weight) of bullheads (during the only year bullheads were captured) and 0.1-17.9% of the diet of northern pike. Ruffe were 0.9-24.5% of the diet of smallmouth bass that contained fish, 1.5-6.9% of yellow perch that contained fish, and 0.0-10.9% of black crappies that contained fish. Most ruffe eaten were age-0 or small age-1 fish. In the laboratory, walleyes that were first fed soft-rayed prey or that were also offered soft-rayed prey consumed very few ruffe, whereas walleyes that were first fed spiny-rayed yellow perch or were also offered yellow perch consumed about equal numbers of ruffe and yellow perch. Northern pike and burbot consumed about equal numbers of ruffe and yellow perch in the laboratory. It is unlikely that predation will effectively control the initial expansion of ruffe in other areas of the Great Lakes because native predators initially consume few ruffe, especially if more preferred soft-rayed prey are available.

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

1996-01-01

224

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

USGS Publications Warehouse

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.

Patino, Eduardo; Byrne, Michael J.

2004-01-01

225

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 ...

226

Organochlorines, brominated flame retardants and mercury levels in six seabird species from the Gulf of St. Lawrence (Canada): relationships with feeding ecology, migration and molt.  

PubMed

Concentrations of organochlorines (OCs), brominated flame retardants (BFRs) and mercury (Hg) were measured in eggs of six seabird species breeding in the Gulf of St. Lawrence, Canada. Stable nitrogen (delta15N) and carbon (delta13C) isotopes were used as ecological tracers to measure trophic level and connectivity with benthos, respectively. Concentrations, patterns as well as ecological tracers varied significantly between species. The sum of polychlorinated biphenyls (SigmaPCBs) was the most important group measured in all seabird species based on concentration followed generally by the sum of chlorinated pesticides (SigmaCPs), the sum of brominated flame retardants (SigmaBFRs) and finally total Hg (THg). SigmaPCBs, SigmaCPs and SigmaBFRs increased with trophic level, whereas THg did not. Only SigmaBFRs increased with a higher connectivity with the benthos. Seabird species resident to the Great Lakes-St. Lawrence ecosystem showed higher Hg and BFR levels than migratory species. Molt patterns were used to explain variations of contaminant levels. PMID:20363539

Lavoie, Raphael A; Champoux, Louise; Rail, Jean-François; Lean, David R S

2010-06-01

227

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

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.

Bishop, C.A. [Environment Canada, Burlington, Ontario (Canada); Koster, M.D. [Springborn Labs. (Europe) AG, Seestrasse (Switzerland); Chek, A.A. [Univ. of Guelph, Ontario (Canada). Dept. of Zoology; Hussell, D.J.T. [Ontario Ministry of Natural Resources, Maple, Ontario (Canada); Jock, K. [St. Regis Mohawk Health Service, Hogansburg, NY (United States)

1995-03-01

228

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

USGS Publications Warehouse

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.

Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

2006-01-01

229

Trends of total cadmium, copper, and zinc in the zebra mussel (Dreissena polymorpha) along the upper reach of the St. Lawrence River: 1994-2005.  

PubMed

This study examines spatial and temporal variability of bioaccumulation of cadmium, copper, and zinc in tissues of zebra mussels in the upper reach of the St. Lawrence River which originates at the outflow of Lake Ontario. It was hypothesized that concentrations of these metals in mussel tissues would decline over time and decrease with increasing distance from the outlet of Lake Ontario as a result of on-going efforts to reduce contaminant discharges into the lake. Size of mussels was also evaluated as a factor influencing bioaccumulation. Mussels were collected annually in October from six sites from 1994 to 2005, including one site near a local industry. Individuals were grouped into five or more size classes per site in each year. Soft tissues were analyzed for total cadmium, copper and zinc. Concentrations of cadmium and copper in tissues varied significantly both spatially and temporally. Cadmium concentrations were elevated at most sites; copper concentrations were moderately elevated compared with other studies in the Lake Ontario basin and St. Lawrence River. Zinc showed the most uniformity in mussels possibly due to internal regulation and to low levels of environmental exposure. Animal size correlated with copper concentrations of tissues in approximately 30% of samples but infrequently for cadmium and zinc. Cadmium and copper levels were found to decline downstream over time. Inter-annual variability of metal concentrations in mussel tissues suggests utilization in long-term monitoring programs to discern significant trends. PMID:21922178

Johns, Carolyn

2012-09-01

230

Chemical dynamics of the "St. Lawrence" riverine system: ?D H 2O, ? 18O H 2O, ? 13C DIC, ? 34S sulfate, and dissolved 87Sr/ 86Sr  

NASA Astrophysics Data System (ADS)

Chemical and stable isotope analyses of the St. Clair, Detroit, Niagara, and St. Lawrence rivers ("St. Lawrence" system) and their tributaries show that the chemical and isotopic compositions of the waters are strongly controlled by the geology of their drainage basins. Tributaries draining the Canadian Shield have very low TDS, HCO 3-, SO 42-, Ca 2+, Mg 2+, NO 3-, Sr 2+, higher Si and Fe total, and high 87Sr/ 86Sr ratios (0.710-0.713). The Grand and Thames rivers that drain Paleozoic limestones, dolostones, and evaporites are characterized by opposite attributes. The "St. Lawrence" and the tributaries draining the Canadian Appalachians fall between these two endmembers. The St. Clair, Detroit, and Niagara rivers do not show any pronounced seasonal variations in major component chemistry due to buffering by the Great Lakes. In contrast, pronounced seasonal variations characterize the lower St. Lawrence mainly because of significant tributary inputs into the overall water budget. The ?D and ?18O in the "St. Lawrence" range from -60.9 to -44.5‰ and from -8.5 to -6.1‰ SMOW, respectively, much heavier than the comparative values measured for the tributaries (-92.8 to -58.3‰ and -13.1 to -8.5‰). This is a consequence of evaporative loss that, over the residence time of water of 10 2 years, equals about 7% of the water volume in the Great Lakes. The strontium and sulfur isotopic values for the "St. Lawrence" system are relatively uniform, with measured values from 0.70927 to 0.71112 for 87Sr/ 86Sr and from 4.3 to 5.6‰ for sulfate ?34S. Their seasonal variations are also minor. The strontium and sulfur fluxes of the St. Lawrence river are calculated to be 7.84 × 10 8 and 1.09 × 10 11 mol/a, respectively. The relative contributions of the Great Lakes, tributaries, and other sources to these fluxes are 73:16:11% for strontium and 64:13:23% for sulfur. Isotopic composition of dissolved inorganic carbon ( ?13C DIC) in the "St. Lawrence" system ranges from -4.7 to +0.7‰, considerably heavier than the values for the tributaries (-16.5 to -6.7‰). The light ?13C DIC values for the tributaries suggest that CO 2 from bacterial respiration plays an important role in the isotopic composition of riverine DIC. However, in the main stem river(s), this bacterial signal is masked by isotopic equilibration with atmospheric CO 2 due to the long residence time of water in the Great Lakes. Seasonally, the main stem river(s) have heavier ?13C values in the fall than in the spring, a consequence of preferential 12C consumption by photosynthetic plants in the epilimnion of the Great Lakes during the growth season. In the down-stream portion of the St. Lawrence river, influx of isotopically light tributary waters causes progressive 13C depletion, from -1.3 to -2.0‰ and -1.4 to -3.0‰ in the fall and spring, respectively. The total DIC carbon flux of the St. Lawrence river is calculated to be 3.9 × 10 11 mol/a. Mass balance calculations show that the relative contributions of the Great Lakes, tributaries, decay of organic matter, exchange with the atmosphere, and dissolution of carbonates to this total DIC flux are 81:13:2:-6:10% in the spring, and 83:15:-2:4:0% in the fall, respectively.

Yang, Chao; Telmer, Kevin; Veizer, Ján

1996-03-01

231

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

PubMed

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

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

2007-08-01

232

Temporal and spatial distribution and production of dissolved gaseous mercury in the Bay St. François wetland, in the St. Lawrence River, Quebec, Canada  

Microsoft Academic Search

Wetlands are valued for their high biodiversity and for their ecosystem services. However, we still do have a poor understanding of their role in the redox transformation of contaminants such as mercury, particularly in fluvial settings. Seasonal and spatial variations in dissolved gaseous mercury (DGM) distribution and production were studied in the Bay St. François, a wetland in the St.

Edenise Garcia; Jerôme Laroulandie; Xavier R. Saint-Simon; Marc Amyot

2006-01-01

233

Les échanges surface-atmosphère du mercure gazeux dans l'écosystème lac Ontario\\/fleuve Saint-Laurent Mercury Surface-Atmosphère Gas Exchange in Lake Ontario\\/St. Lawrence River Ecosystem  

Microsoft Academic Search

SUMMARY This paper présents and discusses mercury surface-atmosphère gas exchange in Lake Ontario\\/St. Lawrence River ecosystem. Atmospheric sources are recognised to be significant in the cycling of global mercury. Being volatile in its elemental and dimethylated forms, mercury is distributed Worldwide. The dominant form of mercury in the atmosphère is gaseous elemental mercury (Hg(°) (- 98%). Cycling of atmospheric mercury

L. POISSANT

234

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

SciTech Connect

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.

Hontela, A.; Duclos, D.; Fortin, R. [Univ. du Quebec, Montreal, Quebec (Canada). Dept. Sciences Biologiques; Dumont, P. [Ministere du Loisir, Montreal, Quebec (Canada)

1995-04-01

235

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)

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.

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

2007-07-01

236

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

PubMed

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 0.137d(-1)) and [MeHg] in periphyton. A similar relationship was found between Kd (0.096 to 0.334d(-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

Hamelin, Stéphanie; Planas, Dolors; Amyot, Marc

2015-04-15

237

Temporal and seasonal variation in acetylcholinesterase activity and glutathione-S-transferase in amphipods collected in mats of Lyngbya wollei in the St-Lawrence River (Canada).  

PubMed

Mats of filamentous algae Lyngbya wollei cover large areas on top of the sediments along the St-Lawrence River. Like most cyanobacteria, L. wollei produce toxins, named lyngbyatoxin (LYNGTX), an analog of saxitoxin. In order to verify the neurotoxic potential of these filamentous cyanobacteria, we collected amphipods within local vegetation at three sites in summer months: a site rich in L. wollei (Lake St-Louis [LSL]) and two urban sites composed of macrophytes but devoid of L. wollei mats (Richelieu River [RICH] and L'Assomption River [ASSO] outlets). The body weight of each amphipod was measured, and the neurotoxicity was estimated with the measurement of acetylcholinesterase (AChE) and glutathione-s-transferase (GST) activities. Levels of protein-bound phosphates were also evaluated, to rule out contamination by Microcystis sp. The results showed that the activity of acetylcholinesterase measured in amphipods in ASSO and RICH was lower than the activity found in amphipods collected in L. wollei mats in LSL. In addition, amphipods found in L. wollei mats at the LSL site have significantly higher GST activity than those located at the two devoid sites, RICH and ASSO. No significant change was observed for protein-bound phosphate levels. This study suggests that the presence of L. wollei triggers potential toxicity. PMID:23702304

Gélinas, Malorie; Lajeunesse, André; Gagnon, Christian; Gagné, François

2013-08-01

238

Bioremediation and Biorestoration of a Crube Oil-Contaminated Freshwater Wetland on the St.Lawrence River  

Microsoft Academic Search

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. Lawarence River at Ste. Croix, Quebec, Canada. The research determined the effectiveness of fertilizer addition in enhancing the biodegradation rates of residual oil. It further examined the

Albert D. Venosa; Kenneth Lee; Makram T. Suidan; Susana Garcia-Blanco; Susan Cobanli; Moustafa Moteleb; John R. Haines; Gilles Tremblay; Melynda Hazelwood

2002-01-01

239

St  

Cancer.gov

St. Joseph Hospital, Orange, California St. Joseph Hospital Cancer Center 1100 West Stewart Drive Orange CA 92863-5600 www.sjo.org • Larry Ainsworth, President and CEO, St. Joseph Hospital • James Padova, MD, Cancer Program Medical Director

240

Speciation and transformation of phosphorus and its mixing behavior in the Bay of St. Louis estuary in the northern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

Water samples were collected for measurements of dissolved, colloidal, and particulate inorganic and organic phosphorus (P) from the Bay of St. Louis estuary in the northern Gulf of Mexico during August 2008 and October 2009. Laboratory mixing experiments were also carried out using end-member river water and seawater to examine key processes and mechanisms controlling the behavior of P during estuarine mixing. Dissolved organic P (DOP) was the dominant species in the total dissolved P (TDP) pool in both lower (S < 10) and higher salinity (S > 25) regions, while dissolved inorganic P (DIP) predominated in mid-salinity regions (S of 10˜20) comprising up to 75% of the TDP. Both DIP and DOP behaved non-conservatively during estuarine mixing showing dramatic changes and transformation between different P species. The total particulate phosphorus (TPP) accounted for up to 85% of total phosphorus (TP = TDP + TPP) in the low-salinity areas but fell to about 38% in higher salinity regions. The quasi-negative correlation between TDP and TPP and the similarity in mixing behavior between field observations and laboratory experiments supported our hypothesis that physicochemical processes, such as dynamic repartitioning between water and particles or adsorption/desorption, are the predominant mechanisms controlling the biogeochemical cycling of P species in the Bay of St. Louis. River export fluxes of DIP could be significantly underestimated without the quantification of particulate P species, especially in more pristine river basins. The value of the distribution coefficient (in terms of logKd) ranged from 4.4 to 5.6 and decreased with increasing suspended particulate matter concentration and salinity, indicating that P is highly particle reactive and the presence of colloidal P may play an important role in the cycling of P in estuarine environments. Colloidal inorganic P (CIP) and colloidal organic P (COP), as quantified by an ultrafiltration permeation model, comprised 0-62% of the DIP and 34-93% of the DOP with the highest values in the river mouth area, suggesting a river source for colloidal P. The % CIP dropped to below the detection limit as salinity increased, whereas % COP first decreased but increased again with increasing salinity, reflecting different sources for CIP and COP in the lower estuary. The DOC/DOP ratio decreased rapidly with increasing salinity indicating a diagenetically older dissolved organic matter pool from the river and a dynamic change in sources and chemical speciation of P in the estuary.

Lin, Peng; Chen, Min; Guo, Laodong

2012-06-01

241

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)

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.

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

2014-05-01

242

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

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)

Eissler, Benjamin B.

1979-01-01

243

Massive mortality of common carp (Cyprinus carpio carpio) in the St. Lawrence River in 2001: diagnostic investigation and experimental induction of lymphocytic encephalitis.  

PubMed

A massive fish kill affecting exclusively common carp (Cyprinus carpio carpio) in the St. Lawrence River, Québec, Canada, during the summer of 2001 was investigated by use of laboratory diagnostic methods and by an attempt to experimentally induce the disease. The ultimate causes of mortality were opportunistic bacterial infections with Aeromonas hydrophila and Flavobacterium sp. secondary to immunosuppression induced by physiologic (i.e., spawning) and environmental (i.e., high temperatures and low water levels) stressors, and possibly enhanced by an infection causing lymphocytic encephalitis observed in 9 of 18 (50%) fish examined. Experimental induction of disease was attempted in captured wild carp by administration of crude and filtered (particulate <0.22 microm) inocula prepared from a homogenate of tissues from carp affected by the natural outbreak. Although significant clinical disease or mortality was not induced by experimental challenge, lymphocytic encephalitis similar to the one observed in naturally affected carp was induced in four of seven (57%) fish administered crude inoculum and four of seven (57%) fish administered filtered inoculum. None of the control fish inoculated with sterile phosphate-buffered saline (n = 6) were affected by encephalitis. The cause of the encephalitis observed in carp from the natural outbreak and in experimentally inoculated fish could not be determined by use of virus isolation and transmission electron microscopy. PMID:16672577

Monette, S; Dallaire, A D; Mingelbier, M; Groman, D; Uhland, C; Richard, J-P; Paillard, G; Johannson, L M; Chivers, D P; Ferguson, H W; Leighton, F A; Simko, E

2006-05-01

244

Modeling the interactions between the seasonal and diel migration behaviors of Calanus finmarchicus and the circulation in the Gulf of St. Lawrence (Canada)  

NASA Astrophysics Data System (ADS)

The Gulf of St.-Lawrence (GSL) is a dynamic region supporting a productive pelagic ecosystem. This environment presents unique opportunities to study the interactions between the population dynamics of planktonic species and the variability of physical processes. The copepod Calanus finmarchicus is a dominant component of zooplankton biomass and abundance in the GSL. We developed a 3-D coupled physical-biological numerical model in order to study the population dynamics of C. finmarchicus in the GSL for the year 1999. We coupled a life cycle model of C. finmarchicus representing the average properties of the population in terms of egg production, development, migration behavior and mortality to a regional circulation model driven by realistic atmospheric, hydrological and oceanic forcing. The distribution and abundance patterns of C. finmarchicus were sensitive to the migration behavior owing to the strong vertical and horizontal shears in the circulation. Both the timing of seasonal ontogenetic vertical migrations and the diel vertical migrations appeared to be essential to produce simulation results similar to the observations and to ensure the perennial presence of a local population in the GSL.

Maps, Frédéric; Zakardjian, Bruno A.; Plourde, Stéphane; Saucier, François J.

2011-11-01

245

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

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.

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

246

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

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.

Metcalfe-Smith, J.L. (Environment Canada, Burlington, Ontario (Canada). Rivers Research Branch)

1994-09-01

247

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

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

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

2004-05-01

248

St  

Cancer.gov

St. Joseph Hospital Cancer Institute Physician Conditions of Participation A. PREAMBLE The vision of St. Joseph Hospital Cancer Institute is to attain the highest level of clinical excellence while providing an exceptional patient

249

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)

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.

Richard, P.; Occhietti, S.

2004-05-01

250

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

E-print Network

. Lawrence River yellow perch (Perca flavescens) Magali Houde a, , Maeva Giraudo a , Mélanie Douville activities to histological changes. Yellow perch (Perca flavescens) were selected based on their wide

Bernatchez, Louis

251

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

PubMed

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

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

252

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

PubMed

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 ?(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 ?(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

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

2015-04-01

253

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

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

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

2009-01-15

254

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

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

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

2013-11-01

255

Spatial and temporal trends of mercury concentrations in young-of-the-year spottail shiners (Notropis hudsonius) in the St. Lawrence River at Cornwall, ON.  

PubMed

The St. Lawrence River at Cornwall, Ontario is an "Area of Concern" because of mercury (Hg) biomagnification from bottom sediments. To assess the spatial and temporal distribution of Hg in the food web, young-of-the-year (YOY) spottail shiners (Notropis hudsonius) were collected in August 2005 from five sites along the Cornwall waterfront within a Hg-contaminated zone and two reference zones. The results were compared to analyses made between 1979 and 2000 by the Ontario Ministry of the Environment. Total Hg concentrations in spottail shiners from the contaminated zone were significantly higher than in reference zones, confirming previous observations. Within the contaminated zone, there were significant differences in Hg concentrations among three sites spaced about 500 m apart, consistent with a high degree of site fidelity of YOY fish and suggesting a possible internal source of Hg. Hg concentrations in spottail shiners are decreasing regionally, although year-to-year variability was high, particularly in the contaminated zone. Stable isotope analyses of spottail shiners did not reveal any differences in nitrogen isotope composition among zones that would indicate differences in food-web structure and Hg biomagnification. However, carbon sources at an upstream reference zone were not the same as within the Area of Concern. Differences in carbon isotope composition at two sites within the contaminated zone corresponded to differences in Hg concentrations, consistent with a unique internal source of Hg. The variation in Hg contamination of YOY spottail shiners over fine spatial and temporal scales provide important insights about the potential release of Hg from contaminated sediments and the role of climate in regional trends. Sessile YOY fish provide a precise indicator for demonstrating these differences and for assessing their cause. PMID:17909881

Choy, Emily S; Hodson, Peter V; Campbell, Linda M; Fowlie, Adrienne R; Ridal, Jeff

2008-04-01

256

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

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).

Aulenbach, Brent T.

2006-01-01

257

Estuary Live!  

NSDL National Science Digital Library

Classrooms and individuals can log on to participate in a real-time field trip to a National Estuary Research Reserve. Ask questions, view live video and still images, and learn about estuaries from experts. Topics range from geology to water quality, estuary plants and animals, and cultural heritage. Includes: references and lesson plans, classroom activities and teachers' guides. Archives of previous years are available, featuring sessions from East, West and Gulf Coast estuaries.

258

Relative weathering intensity of calcite versus dolomite in carbonate-bearing temperate zone watersheds: Carbonate geochemistry and fluxes from catchments within the St. Lawrence and Danube river basins  

NASA Astrophysics Data System (ADS)

Calcite and dolomite solubilities in open weathering environments are proportional to pCO2 and inversely proportional to temperature, and dolomite solubility is progressively greater than calcite below 25°C. The continent-scale weathering budget reveals the significance of the Northern Hemisphere (NH) to globally integrated riverine fluxes of Ca2+, Mg2+, and HCO3-. The NH contributes 70% of the global HCO3- flux while only 54% of the riverine discharge. We present results of a comparative hydrogeochemical study of carbonate mineral equilibria and weathering fluxes in two NH carbonate-rich river basins. Surface water geochemistry and discharge were determined for headwater streams in Michigan and Slovenia within the St. Lawrence and Danube river basins. Michigan watersheds are established atop carbonate-bearing glacial drift deposits derived from erosion of Paleozoic strata with thick soil horizons (100-300 cm). Slovenia watersheds drain Mesozoic bedrock carbonates in alpine and dinaric karst environments with thin soil horizons (0-70 cm). Carbonate weathering intensity is a parameter that normalizes river runoff and HCO3- concentration to catchment area (meq HCO3- km-2 s-1), summing calcite and dolomite contributions, and is used to gauge the effects of climate, land use, and soil thickness on organic-inorganic carbon processing rates. Importantly, Michigan riverine discharge is one-tenth of Slovenian rivers, providing the opportunity to evaluate the kinetics of carbonate mineral equilibration. The study rivers are HCO3- - Ca2+ - Mg2+ waters, supersaturated for calcite at pCO2 values in excess of the atmosphere. As discharge varies, HCO3- concentrations differ by less than 20% for any location, and Mg2+/Ca2+ remains relatively fixed for Michigan (0.5) and Slovenia streams (0.4), requiring that dolomite dissolution exceed calcite on a mole basis. The ability of calcite and dolomite dissolution to keep pace with increased discharge indicates carbonate weathering is limited only by water flux and temperature-dependent solubility in these watersheds. Carbonate weathering intensity in Michigan and Slovenia exceeds the world average by factors between 2 and 20, and dolomite weathering intensity, estimated from riverine Mg2+ fluxes, exceeds the world average by factors between 2 and 15. Thus global fluxes of carbonate-related weathering products appear heavily skewed toward carbonate-bearing environments at higher latitudes with relatively low mean annual temperatures and high discharge.

Szramek, Kathryn; McIntosh, Jennifer C.; Williams, Erika L.; Kanduc, Tjasa; Ogrinc, Nives; Walter, Lynn M.

2007-04-01

259

Relationships among total recoverable and reactive metals and metalloid in St. Lawrence River sediment: bioaccumulation by chironomids and implications for ecological risk assessment.  

PubMed

The availability and bioaccumulation of metals and metalloids, and the geochemical interactions among them, are essential to developing an ecological risk assessment (ERA) framework and determining threshold concentrations for these elements. The purpose of this study was to explore the relationships among total recoverable and reactive metals and metalloid in sediment and their bioaccumulation by chironomids. In the fall of 2004 and 2005, 58 stations located in the three fluvial lakes of the St. Lawrence River and its largest harbour area in Montreal, Canada, were sampled. Nine total recoverable and reactive metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and one metalloid (As) were measured in whole sediment using two extraction methods: HCl/HNO(3) and HCl 1N, respectively. The bioaccumulation of six metals (Cd, Cr, Cu, Ni, Pb and Zn) and As by chironomids was evaluated in a subset of 22 stations. Strong collinearities were observed between some total recoverable or reactive metal concentrations in sediment; two principal clusters, including collinear metals, were obtained. The first one included metals of mainly geological origin (Al, Cr, Fe, Mn, Ni), while the second one included As, Cd, Cu, Pb and Zn, which likely derive mainly from point sources of anthropogenic contamination. Each element also showed strong collinearity between their total recoverable and reactive forms (0.65< or =r < or =0.97). We can conclude that both chemical forms are equivalent for use in statistical models needed to explain biological responses and also in screening risk assessment. However, these relationships are not always proportional. Lower availability percentages were observed for Cd, Cu and Zn in the highly mixed-contaminated area of the Montreal Harbour, even though concentrations in sediment were higher. We observed a significant correlation (0.50< or =r < or =0.56) between concentrations in chironomids and concentrations of both total recoverable and reactive Cr and Pb in sediment. Arsenic was an exception, with accumulation by chironomids being highly related to reactive sediment concentrations. Finally, we observed variable influences of explanatory factors (e.g. sediment grain size, Al, Fe, Mn, S, TOC), depending on which metal or metalloid was being predicted in chironomids. In this context, it is difficult to choose a universal predictive method to explain the bioaccumulation of specific metals, and more research is still needed into normalization procedures that consider a combination of explanatory factors. PMID:17900660

Desrosiers, Mélanie; Gagnon, Christian; Masson, Stéphane; Martel, Louis; Babut, Marc P

2008-01-15

260

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)

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.

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

2001-05-01

261

Exploring Estuaries  

NSDL National Science Digital Library

Defines estuaries and related habitats, reviews their roles in coastal ecology and in supporting human activities. Virtual tours provide history and introduce ecology of representative plans and animals. Presents current threats to estuaries and their wildlife and explains the role of EPA's National Estuary Program in protecting these important coastal resources. Includes: teachers' page with resources and links; games, coloring sheets and glossary for kids.

262

Effects of temperature and circulation on the population dynamics of Calanus finmarchicus in the Gulf of St. Lawrence and Scotian Shelf: Study with a coupled, three-dimensional hydrodynamic, stage-based life history model  

NASA Astrophysics Data System (ADS)

We developed a physical-biological model for the Gulf of St. Lawrence (GSL) and Scotian Shelf (SS) by coupling a stage-based life-history model of the planktonic copepod Calanus finmarchicus to a three-dimensional ocean circulation model. The life-history model consists of 13 morphologically distinct life stages of C. finmarchicus, with stage-specific and temperature-dependent molting rates. The model also includes stage-specific vertical distribution and seasonally varying diapause, egg production, and stage-specific mortality rates. The model domain covers the eastern Canadian shelf from 55°W to 72°W and from 39°N to 52°N, including the Gulf of St. Lawrence, Scotian Shelf, and Gulf of Maine. A comparison of a 1-year simulation with observations indicates that the physical-biological model reasonably describes the observed abundance and distribution of C. finmarchicus in this region. To determine the effects of ocean circulation in the C. finmarchicus population dynamics, we divided the GSL-SS region into eight sub-areas and compared the net fluxes of C. finmarchicus across lateral boundaries to the net production in each sub-area. We found that the annual cross-boundary exchange rates constitute from <1% to 39% of the local net production, indicating that the horizontal transport of C. finmarchicus by the ocean currents can play a very important role in the dynamics of local C. finmarchicus populations. The results provide insights into the mechanisms of exchange in the GSL-SS system, as put forward in recent hypotheses.

Zakardjian, Bruno. A.; Sheng, Jinyu; Runge, Jeffrey A.; McLaren, Ian; Plourde, StéPhane; Thompson, Keith R.; Gratton, Yves

2003-11-01

263

Natal origin of atlantic bluefin tuna (thunnus thynnus) from the gulf of st. lawrence using ?13c and ?18o in otoliths  

E-print Network

Increased knowledge of stock mixing and migration patterns of Atlantic bluefin tuna (Thunnus thynnus) is required to appropriately manage and conserve declining populations. The nursery origin of giant bluefin tuna present in the Gulf of St...

Schloesser, Ryan Walter

2009-05-15

264

Water and sediment dynamics at Saint Lawrence River mouth  

Microsoft Academic Search

The main features of the hydrological regime and morphological structure of the estuarine-type mouth area of the Saint Lawrence\\u000a River are considered. Data on the structure of water masses, thermal and ice regimes in the Gulf of Saint Lawrence, which\\u000a has a significant effect on the estuary, are given. The major attention is paid to water mixing processes, water and

E. N. Dolgopolova; M. V. Isupova

2011-01-01

265

Estuary Live!!!  

NSDL National Science Digital Library

Intended for elementary, middle, and high school students, this electronic estuary excursion, Estuary Live!!!, will take place May 8-12, 2000. Free to participants (but please sign up in advance), the field trip will explore the Rachel Carson Site of the North Carolina National Estuarine Research Reserve, covering four islands and salt marshes off the North Carolina coast. The site features useful educational materials, including a photo-illustrated field guide (of the "ecology, habitats and specific plants and animals found in North Carolina's estuaries"); lesson plans (covering highschool biology, estuary habitats, species interactions, and adaptations and communities); and a series of related links. The interactive field trip will require a java-enabled browser, RealVideo (to see a moving image and hear sound), and/or Chatvideo, to see a moving image, ask questions of the naturalist leading the trip, and receive responses via a chat window. Note that ChatVideo requires Netscape 4.0 or better and will not work with AOL or Internet Explorer, and pages "look best" on a screen with resolution of 800x600. The Estuary Live!!! Website is provided by the North Carolina National Estuarine Research Reserve Program, and The Center for Science, Mathematics and Technology Education at East Carolina University.

266

Occurrence of alkylphenols and alkylphenol mono- and diethoxylates in natural waters of the Laurentian Great Lakes basin and the upper St. Lawrence River  

Microsoft Academic Search

Nonylphenol and its ethoxylates are on the second priority substances list (PSL2) to determine if they are ‘toxic’ as defined under the Canadian Environmental Protection Act. This study addresses the need for data on their occurrence in surface waters and sediments in Canada. Samples of surface water from 35 sites in the Laurentian Great Lakes basin and the upper St.

D. T. Bennie; C. A. Sullivan; H.-B. Lee; T. E. Peart; R. J. Maguire

1997-01-01

267

Exploring Estuaries  

NSDL National Science Digital Library

This site offers several ways to explore the importance of estuaries. Virtual tours of the Barataria-Terrebone Estuarine Complex and the Long Island Sound offer photos and text of each area explain their importance to humans, wildlife, and larger ecosystems. Additional resources for kids and adults are linked. A glossary page offers a list of vocabulary associated with estuaries. The site also offers a games and activities section for kids that has coloring sheets for young children, and inquiry-based interactive games for older kids. The games include a "Who Am I" animal identification game, and a game called "Solve a Mystery" where players must follow and investigation into what's wrong with an estuary, and make a decision on the cause of the problem. There are several possible mysteries to solve, each with a different solution.

268

Preliminary report on the regional geology, oil and gas potential and environmental hazards of the Bering Sea shelf south of St. Lawrence Island, Alaska  

Microsoft Academic Search

The Bering Sea shelf is underlain by at least 11 basins that are prospective sites for hydrocarbon accumulations. These basins encompass a combined area over 546,000 km² (211,000 mi²), larger than the size of the state of California. Geophysical data indicate that two of the basins (St. George and Navarin) contain more than 10 km (6.2 mi) of Upper Cretaceous

M. S. Marlow; H. McLean; T. L. Vallier; D. W. Scholl; J. V. Gardner; R. B. Powers

1976-01-01

269

Common cyclicities in the seismicity and water level fluctuations at the charlevoix seismic zone on the St Lawrence River, Quebec, Canada  

NASA Astrophysics Data System (ADS)

Intraplate seismicity has no widely accepted explanation for its origin. The hydroseismicity hypothesis suggests that natural increases in hydraulic head, caused by transient increases in water table elevation, can be transmitted to hypocentral depths (10-25 km) in a fractured, prestressed, near-failure crust, and, along with long term hydrolytic weakening of rocks, contribute to the triggering of earthquakes. In this study, the temporal characteristics of seismicity and water level fluctuations at the Charlevoix seismic zone on the Saint Lawrence River in Quebec, Canada, are determined using Fourier spectral analysis and are investigated for possible temporal relationships, as predicted by hydroseismicity, using group delay analysis. Fourier spectral analysis of the temporal release of seismic energy indicates the presence of short term cyclicities of periods of 13-14 yr, along with longer term periods of approx. 55-70 yr. Spectral analysis of the water level data indicates cyclicities with periods of 1, 23, 14 and 8 years. Group delay analysis of the 14 yr periodicities in the water level and seismicity time series yields a time lag of 2.3-2.6 yr, with the water levels leading the seismicity time series. Crustal diffusivity values estimated from the group delay analysis range between 0.3 and 2.7 m 2/s, for a depth interval from 7 to 20 km, which is within the range of published values of diffusivities for the crust (0.1-100 m 2/sec). The present study suggests that common cyclicities are present in both the water levels and seismicity in the Charlevoix region. Such cyclicities are an essential element of the hydroseismicity hypothesis for the diffusion of surficial fluid pressure variations to hypocentral depths. Furthermore, the temporal relationship between the cyclicities observed allows for a possible causal relationship between repetitive mechanical effects of pore pressure transients and seismicity in the Charlevoix region.

Tsoflias, George P.; Bollinger, G. A.; Costain, John K.

1995-03-01

270

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...

271

Eutrophication of the St. Lawrence Great Lakes  

USGS Publications Warehouse

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.

Beeton, Alfred M.

1965-01-01

272

Welcome to Estuaries  

NSDL National Science Digital Library

This resource features three sections devoted to learning about estuaries: an online tutorial, an educational roadmap to resources, and formal lesson plans. The tutorial shows how estuaries are classified by their geology and water circulation patterns, the various ecosystem services estuaries perform, how organisms have adapted to the unique environmental conditions found in estuaries, the many disturbances that estuaries face from nature and human activities, and finally, the essential work that the National Estuarine Research Reserve System and its many partners conduct to monitor, preserve, and restore estuarine ecosystems throughout the United States. The roadmap to resources provides a set of links to specific data related to the information presented in the tutorial. Lesson plans on estuaries are also provided.

273

Regional Differences Among Estuaries  

NSDL National Science Digital Library

This text discusses differences in estuaries in different regions of the United States. It contrasts the fjord-like estuaries of the rocky Maine coast with the sandy barrier beaches, islands, and enclosed bays and sounds further south. The site also calls attention to the difference between the East Coast and the Northwest coast of emergence. The point is made that although they differ, all estuaries have great value and many are in danger.

Oberrecht, Kenn

274

Learning Lessons from Estuaries  

ERIC Educational Resources Information Center

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…

Schnittka, Christine

2006-01-01

275

Nutrients in an Estuary  

NSDL National Science Digital Library

In this activity, learners model estuaries, artificially enriching both fresh and salt water samples with different amounts of nutrients and observing the growth of algae over several weeks. Learners relate their results to the phenomenon of algae blooms in estuaries. Learners then analyze data for different sites at the Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR) in Florida to discover the relationships between nitrogen, chlorophyll, and dissolved oxygen. Finally, learners study how nutrients cycle through an estuary and suggest recommendations for reducing nutrient inputs to estuary waters.

TERC

2012-06-26

276

The Stephen Lawrence Inquiry  

NSDL National Science Digital Library

In 1993, 18-year-old Stephen Lawrence was stabbed to death in London in a racially motivated attack. Lawrence's killers have not been successfully prosecuted, and, as this report released by the UK Home Office on February 24 reveals, the London police inquiry into the crime displayed "professional incompetence and institutional racism." Undoubtedly the most infamous racial murder in recent British history, Lawrence's death, the police investigation, and the far-reaching government inquiry which followed are being regarded as a milestone in British race relations, inspiring new private and government initiatives to improve relations as well as proposals for extensive changes in the UK policing and judicial systems. Users can read the full text of Sir William Macpherson's 352 page report at the UK Sationary Office site.

277

National Estuary Program  

NSDL National Science Digital Library

Estuaries are places where rivers meet the sea and are critical to the health of coastal environments and our enjoyment of them. Website features abundant information on the legal and scientific aspects of estuary preservation. Includes guidelines, program profiles, and a shorter version in Spanish. Resources for teachers and students include games and activities. External links to additional programs also provided.

278

DYNAMIC ESTUARY MODEL PERFORMANCE  

EPA Science Inventory

Applications of the Dynamic Estuary Model (DEM) to both the Delaware and Potomac Estuaries by the Environmental Protection Agency during the 1970s are summarized and evaluated. Methods for calibrating, refining, and validating this model, and statistics for evaluating its perform...

279

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...

280

Decline of Canada geese (Branta canadensis) and common goldeneye (Bucephala clangula) associated with a collapse of eelgrass (Zostera marina) in a Nova Scotia estuary  

NASA Astrophysics Data System (ADS)

Mean numbers of migrant Canada geese (Branta canadensis) in Antigonish Harbour in the southern Gulf of St. Lawrence (Canada) during October to December were similar (approx. 450-500 birds) for the period 1998-2000. Similarly, during this period, geese used two foraging sites. However, in 2001, the average number of birds decreased by half and the primary foraging sites were used only rarely. This coincided with a decline of about 95% in the biomass of roots and rhizomes of eelgrass (Zostera marina) that occurred between October 2000 and 2001. Eelgrass is the principal food of geese in this estuary. In addition, there was a reduction of around 50% in the numbers of common goldeneye (Bucephala clangula), which feed on invertebrates associated with eelgrass. Lower than usual weekly abundances of geese and goldeneye are probably the result of an unusually short residence time in the estuary, rather than a decline in the total number of visiting migrants. We attribute these changes in the distribution and abundance of geese and goldeneyes to the dramatic decline in eelgrass.

Seymour, Norman; Miller, Anthony; Garbary, David

2002-08-01

281

Sex alteration in soft-shell clams ( Mya arenaria) in an intertidal zone of the Saint Lawrence River (Quebec, Canada)  

Microsoft Academic Search

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

F Gagné; C Blaise; J Pellerin; E Pelletier; M Douville; S Gauthier-Clerc; L Viglino

2003-01-01

282

Lawrence Hall of Science  

NSDL National Science Digital Library

Lawrence Hall of Science is a resource center for preschool through high school science and mathematics education, and a public science center with hands-on experiences for learners of all ages. Home of the William Knox Holt Planetarium, there is extensive educational programming centered on astronomy, including Planetarium Activities for Student Success kits for purchase that illustrate basic principles of astronomy. Earthquakes, erosion, wind and weather are the focus of the Forces that Shape the Bay exhibits, and there are also a number of exhibits highlighting math and physics. The website provides many online games and home activities available for download. The Lawrence Hall of Science Center for Curriculum Innovation creates instructional materials in mathematics and science for preschool through 12th graders for use by students, teachers and other educators, parents and families, and the website provides an array of information on the various programs. Title II funding for professional development is available.

283

Restore America's Estuaries  

NSDL National Science Digital Library

This non-profit organization promotes the restoration and protection of America's estuaries. Projects encompass scientific research, education and community-based action, including restoration by school youngsters, as well as policy initiatives at the national level. An introduction to estuaries contains concise definitions, value in ecology and economics, current threats, and elements of restoration. Also offers: links to educational resources; news and photo gallery; a CD-rom guide to estuarine restoration.

284

Carl Steefel Earth Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mail Stop 90-1116,  

E-print Network

Carl Steefel Earth Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mail.A. English Literature, 1974, Washington University, St. Louis, MO. Biography Carl Steefel obtained his B

Ajo-Franklin, Jonathan

285

Estuarine Science: All About Estuaries  

NSDL National Science Digital Library

Estuaries are partially enclosed bodies of water along coastlines where fresh water and salt water meet and mix. They act as a transition zone between oceans and continents. This site examines various aspects of estuaries, focusing on the geological features that make an estuary, as well as the water circulation patterns by which they are classified. It also has a section that allows the user to access additional text and graphics on many of the estuaries of the world.

286

Lawrence Denny Lindsley Photographs  

NSDL National Science Digital Library

Lawrence Denny Lindsley was born in 1878 in a house on scenic Lake Union, right in the middle of the relatively young city of Seattle, Washington. As a descendant of the early Seattle pioneer David Denny, Lindsley began to wander around the city and its environs from a young age. Like many men in the Pacific Northwest during the late 19th century, he enjoyed the outdoors, and soon developed a skill for photography. He later went on to work for Edward Curtis, and he continued on by documenting such landscapes as Mount Rainer, Lake Chelan, and the Olympic Peninsula. Many of these excellent photographs can be viewed in this latest offering from the University of Washington Libraries Digital Collection. All told, there are 472 photographs here, complete with detailed records. The King County section is a real highlight, as visitors will get a real sense of the area before it became heavily urbanized during the 20th century.

2006-01-01

287

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,...

288

Lawrence Berkeley National Laboratory  

NSDL National Science Digital Library

Arguably the most famous government research laboratory in the United States, the Lawrence Berkeley National Laboratory is supported by the U.S. Department of Energy and managed by the University of California. Scientists associated with the laboratory have received a number of accolades over the years, including 13 Nobel Prizes and 13 National Medals of Science. The materials on the site are divided into five primary sections, including About the Lab, For Staff and Guests, and Visitor's Guide. First-time users may wish to start with the News Center. Here they can read press releases and features, and watch videos of scientists talking about their work. The Video Glossary contains wonderful clips of scientists talking about atmospheric aerosols, energy efficiency, and myriad other topics. The general public won't want to miss the "$ Ways to Save Money on Energy" section and the equally compelling area on Globally Transformative Technologies. The site is rounded out by a place where visitors can follow the Laboratory's activities via Facebook, Twitter, and YouTube.

289

Ecology of estuaries  

SciTech Connect

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.

Kennish, M.J.

1986-01-01

290

MERCURY CONTAMINATION OF THE LOWER ST. LOUIS RIVER: WAYS AND MEANS FOR MITIGATION  

EPA Science Inventory

Observations of mercury-contaminated fish in the St. Louis River Estuary and knowledge of past mercury discharges into the river which occurred upstream (mainly at Cloquet, MN), prompted this study ......

291

Organotins in Zebra Mussels ( Dreissena polymorpha) from the Saint Lawrence River  

Microsoft Academic Search

Toxic antifouling compounds such as organotins have been released in the aquatic ecosystems throughout the world and can be bioaccumulating in biota. The purpose of this study was to assess the use of zebra mussels (Dreissena polymorpha) as a biomonitor for investigating the geographical variations of organotin bioavailability along the St. Lawrence River. The presence of organotins (tributyltins (TBT) and

Lidia Regoli; Hing Man Chan; Yves de Lafontaine

1999-01-01

292

A detailed magnetic survey of the Saint Lawrence River: Oak Point to Lake Ontario, New York  

Microsoft Academic Search

Measurements of the total intensity of the Earth's magnetic field in the St. Lawrence River between Oak Point and Lake Ontario indicated magnetic anomalies of high magnitude and steep gradients due to rocks of varying magnetic susceptibility in the Precambrian basement complex. The anomalies and magnetic contours that trend continuously across the river indicated no large lateral offset in this

F. Revetta; J. Cardinal

1979-01-01

293

Estuaries of South Africa  

NASA Astrophysics Data System (ADS)

Estuaries of South Africa presents an authoritative and comprehensive review of the current status of that country's estuarine research and management. Contributors provide information on a wide range of topics, including geological, physical and chemical processes; diversity and productivity of plant and animal communities; interactions among estuarine organisms; and system properties, ecological modeling and current management issues. This broad scope is complemented by a comparative perspective, resulting in a volume that provides a unique contribution to the subject of estuarine ecology. This volume is relevant to all those working in this field throughout the world.

Allanson, Brian; Baird, Dan

1999-05-01

294

Lawrence CV 1 Shawn A. Lawrence, PhD, LCSW  

E-print Network

students: Ethnic and gender differences. Journal of Ethnicity in Substance Abuse, 9(4), 284-300. #12, and negative consequences. Journal of Child & Adolescent Substance Abuse, 21(3), 222-237. DOI: 10.1080/1067828X & Adolescent Social Work Journal, 27(4), 309-321. Lawrence, S. A., Hazlett, R., & Hightower, P. (2010

Wu, Shin-Tson

295

Lawrence CV 1 Shawn A. Lawrence, PhD, LCSW  

E-print Network

. Social Work Education: An International Journal, doi: 10.1080/02615479.2010.541236 Lawrence, S. A., Mazur with obesity: Implications for social work practice and research. Child & Adolescent Social Work Journal, 27: slawrence15@cfl.rr.com Current Position: 8/2005-Present Associate Professor (Promoted Fall 2011) University

Van Stryland, Eric

296

Wenchuan Li Y. Lawrence Yao  

E-print Network

Wenchuan Li Y. Lawrence Yao Department of Mechanical Engineering, Columbia University, New York, NY and stress/strain obtained from experimentally validated simulation models are also used to better understand conditioners, and tubing and pipe prod- ucts. Tubes may be mechanically bent either when hot or cold, although

Yao, Y. Lawrence

297

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...

298

Lawrence Livermore National Laboratory Internships  

NSDL National Science Digital Library

Lawrence Livermore National Laboratory Internships -- The Lawrence Livermore National Laboratory (LLNL) hosts 300 to 400 undergraduate and graduate students and some faculty every summer in support of its world-class scientific facilities and staff and in an effort to help train the nation's next generation of scientists and engineers.

Involvement in world-class research provides participants with a set of experiences that support their education and career goals. Typically, participants gain hands-on experience and the opportunity to apply learned theory to real life problems. An experience of this type, and with these resources at a premier state-of-the-art research laboratory is not available in an academic research lab.

299

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 ...

300

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...

301

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 ...

302

Estuaries and Clean Water Act of 2000  

NSDL National Science Digital Library

The Office of Water at the Environmental Protection Agency has posted online this document on the new Estuaries and Clean Water Act of 2000. Available in .pdf format, the document summarizes the Act, which emphasizes restoration of estuary habitat.

303

Estuaries: Where Rivers Meet the Sea  

NSDL National Science Digital Library

Take your students on an EstuaryLive telecast! EstuaryLive brings free, live internet field trips in four different estuaries around the country, right to your classroom. These online field trips are the next best thing to an actual trip to an estuary, providing students with an exciting and new way to learn about unique estuarine ecosystems. The site also includes archived webcasts and teacher resources including classroom activities and a glossary.

304

Exploring Physical and Biological Mechanisms for Zooplankton Retention in the Estuarine Transition Zone of a Riverine Estuary  

NASA Astrophysics Data System (ADS)

In this study, we use a coupled three-dimensional physical-biological model to investigate zooplankton retention in the estuarine transition zone (ETZ) of the St. Lawrence Estuary (SLE). Varying from well-mixed to partially stratified, the hydrodynamic environment of the SLE is defined by a large tidal range, strong salinity gradients, a large freshwater river flow, and complex bathymetry. The physical-biological model used for this study consisted of two parts: a circulation model and a zooplankton transport model. The circulation model is a three-dimensional Eulerian hydrodynamic model (TRIM3D) driven by the wind, tides, and freshwater outflow. The zooplankton transport model is a three-dimensional Lagrangian particle tracking model which simulates zooplankton movement using velocity fields derived from the three-dimensional circulation model. The circulation model is calibrated using field data such as salinity, pressure, and current time series from different locations in the ETZ. The transport and distribution of three zooplankton taxa, non-native zebra mussel veligers, resident mysids, and larval smelt, were simulated for this study. By simulating these three taxa, we were able to investigate the effect of a range of swimming speeds on zooplankton retention in the ETZ. We present the results of simulations exploring the efficiency of tidal vertical migration, a commonly described biological retention mechanism that is characterized by zooplankton migration up to the surface on flood and down to the bottom on ebb. Tidal vertical migration, also known as selective tidal stream transport, was investigated for several swimming speeds and endogenous rhythms.

Simons, R. D.; Monismith, S. G.

2002-12-01

305

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...

306

Future variability of solute transport in a macrotidal estuary  

NASA Astrophysics Data System (ADS)

The physical controls on salt distribution and river-sourced conservative solutes, including the potential implications of climate change, are investigated referring to model simulations of a macrotidal estuary. In the UK, such estuaries typically react rapidly to rainfall events and, as such, are often in a state of non-equilibrium in terms of solute transport; hence are particularly sensitive to climate extremes. Sea levels are projected to rise over the 21st century, extending the salinity maximum upstream in estuaries, which will also affect downstream solute transport, promoting estuarine trapping and reducing offshore dispersal of material. Predicted 'drier summers' and 'wetter winters' in the UK will influence solute transport further still; we found that projected river flow climate changes were more influential than sea-level rise, especially for low flow conditions. Our simulations show that projected climate change for the UK is likely to increase variability in estuarine solute transport and, specifically, increase the likelihood of estuarine trapping during summer, mainly due to drier weather conditions. Future changes in solute transport were less certain during winter, since increased river flow will to some extent counter-act the effects of sea-level rise. Our results have important implications for non-conservative nutrient transport, water quality, coastal management and ecosystem resilience.

Robins, Peter E.; Lewis, Matt J.; Simpson, John H.; Howlett, Eleanor R.; Malham, Shelagh K.

2014-12-01

307

Lawrence Berkeley National Laboratory: VISTA  

NSDL National Science Digital Library

A very comprehensive and well-organized offering from Lawrence Berkeley National Laboratory, VISTA offers "suite of programs and databases for comparative analysis of genomic sequences. There are two ways of using VISTA - you can submit your own sequences and alignments for analysis (VISTA servers) or examine pre-computed whole-genome alignments of different species (VISTA browser)." The site also offers up-to-date updates on genomic sequences. Included in the April 2004 update are the Human-Chimpanzee, Human-Chicken, and D.melanogaster-Honey Bee whole genome alignments. VISTA is definitely a site for researchers and students involved in genomic research.

308

Lawrence University: Images & Digital Collections  

NSDL National Science Digital Library

Appleton, Wisconsinâ??s, Lawrence University continues to work diligently to digitize its library holdings that might be of interest to the general public. These collections include items from the department of theatre arts, along with items from Lux, the online home for the universityâ??s scholarly and creative works. It's a great way to learn about some of its most compelling projects, including wonderful honor projects, such as "Learning from Experience: A Philosophical Perspective." Moving on, the theatre arts area contains images, programs and other bits of ephemera from shows like Cabaret, Cinderella, and much more.

309

Brazilian Theatre in Lawrence, Kansas  

E-print Network

38 LATIN AMERICAN THEATRE REVIEW Brazilian Theatre in Lawrence, Kansas In late April and early May, a handful of U.S. audiences had the opportunity to witness one of the most interesting theatrical productions to come from Latin America... in memory. Under the auspices of the Brazilian Ministry of Education and Culture, the Brazilian Dramatic Company (sponsored by the Serviço Na cional do Teatro) performed in two big-city theatres (Kennedy Center in Wash ington, D.C., and La Mama in New...

Vincent, Jon S.

1979-10-01

310

Lawrence Livermore National Laboratory 2007 Annual Report  

SciTech Connect

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

Chrzanowski, P; Walter, K

2008-04-25

311

Ecology of estuaries: Anthropogenic effects  

SciTech Connect

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.

Kennish, M.J.

1992-01-01

312

The Modification of an Estuary  

NASA Astrophysics Data System (ADS)

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.

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

1986-02-01

313

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...

314

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

315

Monthly water balance in tributary watersheds of the Great Lakes Saint Lawrence River basin as influenced by climatic factors  

Microsoft Academic Search

SUMMARY: We observe in this basin the variation of the climate from pure oceanic at the Atlantic shores to continental at the west shores of Lake Michigan and the west extremity of Lake Superior. The type of hydrology generated by tributaries to the Great Lakes and to the St. Lawrence River is Lhe product of the climate dominating the tributary

Boris S. Browzin

316

Subtidal variability in water levels inside a subtropical estuary  

NASA Astrophysics Data System (ADS)

Year-long time series of water level are analyzed at five locations along the St. Johns River Estuary, Florida, to investigate propagation of subtidal pulses. Hilbert-transformed Empirical Orthogonal Functions (HEOFs) are obtained after a dominant seasonal signal is extracted from the data. These functions provide information on spatial structure and propagation phase of subtidal water level pulses. The first HEOF mode explains 96% of the subtidal variability and features an unusual spatial structure: amplitude attenuation (averaging 1 mm/km) to 55 km upstream, slight amplification (0.16 mm/km) over the middle 70 km, and attenuation (2.3 mm/km) over the final 18 km of the estuary. The phase suggests a shift from progressive to quasi-standing wave behavior at 55 km from the estuary mouth. Additionally, local minima in the phase suggest two sources of subtidal forcing: the coastal ocean and the upstream end. An analytical model describing the evolution of long waves through a channel with frictional damping is fit to the amplitude of HEOF mode 1. Solutions are obtained as a function of two parameters: the nondimensional length of the basin, ?, and the nondimensional frictional depth, ?. Values of ? between 0.55 and 0.67 and ? between 1.45 and 1.7 provide the best fit with the HEOF results (1% error or less). These values indicate a highly frictional environment in which the average subtidal wavelength is 10 times the basin length. Subtidal pulses in this estuary, therefore, behave as damped waves that can be represented with idealized models.

Henrie, Krista; Valle-Levinson, Arnoldo

2014-11-01

317

Lawrence and Harlem: Reviving Transit Friendly Areas  

E-print Network

Lawrence #12;+ Major Activity Centers Lawrence: Uptown Harlem: Oak Park, Forest Park, and River Forest" to expand the APA & Congress of New Urbanism award winning improvements along Marion Street to South Boulevard by the CTA station. "Oak Park... stands to be a regional model for local revitalization

Illinois at Chicago, University of

318

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...

319

SAN FRANCISCO ESTUARY INSTITUTE CONTRIBUTION  

E-print Network

Quality Impacts Due to Dredging and Disposal on Sensitive Fish Species in San Francisco Bay Prepared Figure 3-1. Chemical processes upon resuspension caused by dredging. ...............................................................19 Figure 3-2. Location of sediment sampling at San Francisco Estuary dredging projects (1993 ­ 2003

320

The Value of Healthy Estuaries  

NSDL National Science Digital Library

Healthy estuaries are critical to humans and wildlife. They provide food, supporting both commercial and recreational fisheries, treat waste and runoff to maintain water quality, protect coastal areas from natural hazards, connect bodies of water for transportation and marine operations, and nurture a balance of the food web upon which all life depends.

Robert Christian (Thomas Harriot College of Arts and Sciences; )

2009-03-22

321

SAN FRANCISCO ESTUARY INSTITUTE CONTRIBUTION  

E-print Network

on the Margins of San Francisco Bay Final Report An RMP Technical Report by Craig Jones Sea Engineering, Inc Estuary Institute #12;This report should be cited as: Jones, C., Yee, D., Davis J. A., McKee, L. J on the Margins of San Francisco Bay. Draft Report. An RMP Technical Report. Contribution No. 663. San Francisco

322

Macrobenthos composition, distribution and abundance within Sungai Pulai estuary, Johor, Malaysia  

NASA Astrophysics Data System (ADS)

Macrobenthos are very useful organisms for monitoring marine environmental and widely use in marine ecology research. They are able to monitor the difference phase in the recovery stage of disturbed sites by appear different species macrobenthos after the cessation of the impact. Univariate and multivariate methods were use to study the macrobenthos community within Sungai Pulai estuary, Johor, Malaysia. Five sub-samples were taken at each sampling sites by using 10 cm diameter corer. Crustaceans were the most abundant at Tanjung Adang (St. 1) and the station of non-seagrass area (St. 2) while polychaetes were the most abundant at Merambong Shoal (St. 3). Higher density of macrobenthos was found at St.3 followed by St. 1 and St. 2. The commonly used population indices such as diversity, richness, evenness and dominance were employed to determine the differences in diversity and abundance of macrobenthos. The diversity, richness and evenness index values showed slight increment from Station 1 to Station 3, while the dominance index decreasing trend from Station 1 to Station 3. A total 21 polychaete families were collected in Sungai Pulai estuary, which was dominated by the Spionidae, Capitellidae and Glyceridae. Cluster (Bray-Curtis similarities) analyses revealed that the Tanjung Adang and Merambong Shoal population were clearly separated from the station non-seagrass. For the time being factors that influence the pattern of distribution of the macrobenthos cannot be determined and subjected to further studies.

Shi, Guan Wan; Min, Lee Di; Ghaffar, Mazlan Abd; Ali, Masni Md; Cob, Zaidi Che

2014-09-01

323

Carbon dioxide emissions from Indian monsoonal estuaries  

NASA Astrophysics Data System (ADS)

Estuaries are known to be strong source for atmospheric CO2, however, little information is available from Indian estuaries. In order to quantify CO2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge (wet) period. The emissions of CO2 to the atmosphere from Indian estuaries were 4-5 times higher during wet than dry period. The pCO2 ranged between ˜300 and 18492 ?atm which are within the range of world estuaries. The mean pCO2 and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO2 fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is >10 times less than that from the European estuaries. The low CO2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.

Sarma, V. V. S. S.; Viswanadham, R.; Rao, G. D.; Prasad, V. R.; Kumar, B. S. K.; Naidu, S. A.; Kumar, N. A.; Rao, D. B.; Sridevi, T.; Krishna, M. S.; Reddy, N. P. C.; Sadhuram, Y.; Murty, T. V. R.

2012-02-01

324

The Need for Definitions in Understanding Estuaries  

NASA Astrophysics Data System (ADS)

This paper considers what the definition/classification of estuaries has taught us and why there is a need for classification systems. It further considers why we need to define an estuary and its constituent parts, including the fundamental difficulty and dilemma of trying to define parts of a continuum, as a means to both understanding and managing that estuary. The review considers where an estuary starts and ends and the relative merits of defining estuaries in terms of their biology, physics, chemistry, geographic nature and socio-economic units. It briefly discusses the need for legal and planning definitions and the linkages between science and management. Following this, we present a generic framework for the definition, classification, monitoring, assessment, reporting and management of estuaries. In particular, it is argued that scientists should engage in the debate on the definition of estuaries for legal and socio-economic purposes. It is concluded here that as existing definitions will never be suitable for all needs, a different approach is required. The proposed ' Expert Judgement Checklist Approach ' could provide guidance for those needing to define/delimit an estuary while still acknowledging the inherent variability of such systems. The proposed system mostly relates to the European, temperate estuary, but there are lessons here for estuaries worldwide.

Elliott, M.; McLusky, D. S.

2002-12-01

325

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Policy task force goals and in identifying focus areas for the estuary habitat restoration strategy, such as: climate adaptation restoration, socio-economic benefits of estuary habitat restoration, and geographic restoration...

2010-06-21

326

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...

327

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 ...

328

MERCURY CONTAMINATION ASSESSMENT AND TESTS FOR MITIGATION OF CONTAMINATED RESERVOIR SEDIMENTS IN THE LOWER ST. LOUIS RIVER  

EPA Science Inventory

Observatioins of mercury contaminated fish in the St. Louis River estuary and knowledge of past mercury discharges into the St. Louis River which occurred upstream (at Cloquet, MN), prompted this study of mercury contamination in the lower six reservoirs located on the river....

329

Morphodynamic equilibrium of alluvial estuaries  

NASA Astrophysics Data System (ADS)

The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final equilibrium state is reached through an erosional wave, which leads to bed degradation of the upstream 'fluvial reach'. For a given river discharge, the length of the tidal reach increases quite rapidly with tidal amplitude, up to some threshold value of the tidal amplitude above which the length of the estuary becomes comparable with the length of the tidal wave. When the channel plan-form is convergent, deposition of sediments of fluvial origin in the funnel-shaped region drastically changes the equilibrium configuration. The effect of an increasing channel convergence is thus to induce bed aggradation close to the inlet. Nevertheless, tidal forcing only slightly changes the non-tidal profile. The effect of increasing tidal oscillations again leads to an increase of the bed slope at the inlet and to a general bed degradation upstream. The effects of varying sediment supply, flow discharge and river width in the upstream reach have also been investigated and play an important role. Further geomorphological implications of these results will be discussed at the meeting. References Dalrymple, R. W., and K. Choi (2007), Morphologic and facies trends through the fluvialmarine transition in tide-dominated depositional systems: A schematic framework for environmental and sequence-stratigraphic interpretation, Earth-Science Reviews, 81(3-4), 135-174, doi:10.1016/j.earscirev.2006.10.002. Seminara, G., M. Bolla Pittaluga, and N. Tambroni (2012), Morphodynamic equilibrium of tidal channels, Environmental Fluid Mechanics: Memorial Volume in Honour of Prof. Gerhard H. Jirka, 153-174

Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

2014-05-01

330

VOCAL COPYING IN LAWRENCE'S AND LESSER GOLDFINCHES  

Microsoft Academic Search

With perhaps the exception of the Northern Mockingbird, no bird in the western United States copies the vocalizations of such a wide variety of bird species with such proficiency as the Lawrence's Goldfinch. Although this vocal \\

J. V. REMSEN; KIMBALL GARRETT; RICHARD A. ERICKSON

1982-01-01

331

Carbon dioxide emissions from Indian monsoonal estuaries  

NASA Astrophysics Data System (ADS)

The oceans act as a net sink for atmospheric CO2, however, the role of coastal bodies on global CO2 fluxes remains unclear due to lack of data. The estimated absorption of CO2 from the continental shelves, with limited data, is 0.22 to 1.0 PgC/y, and of CO2 emission by estuaries to the atmosphere is 0.27 PgC/y. The estimates from the estuaries suffer from large uncertainties due to large variability and lack of systematic data collection. It is especially true for Southeast Asian estuaries as the biogeochemical cycling of material are different due to high atmospheric temperature, seasonality driven by monsoons, seasonal discharge etc. In order to quantify CO2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge wet and dry periods. The emissions of CO2 to the atmosphere from Indian estuaries were 4-5 times higher during wet than dry period. The pCO2 ranged between ~300 and 18492 microatm which were within the range of world estuaries. The mean pCO2 and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO2 fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is >10 times less than that from the European estuaries. The low CO2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.

Sarma Vedula, VSS

2012-07-01

332

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...

333

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...

334

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 ...

335

MLK & Brother Lawrence Hanks Lawrence Hanks & Dr. Martin Luther King, Jr.  

E-print Network

MLK & Brother Lawrence Hanks Lawrence Hanks & Dr. Martin Luther King, Jr. Dr. Martin Luther King Jr who has taken many non-violent actions in line with legacy of Dr. Martin Luther King, Jr. To truly University observe Martin Luther King Day as a holiday in 1993 (Malagon, 2011). Dr. King's argument has

Indiana University

336

Hydrogen Storage atHydrogen Storage at Lawrence Berkeley National LaboratoryLawrence Berkeley National Laboratory  

E-print Network

Hydrogen Storage atHydrogen Storage at Lawrence Berkeley National LaboratoryLawrence Berkeley National Laboratory Presentation at thePresentation at the Hydrogen Storage Grand ChallengeHydrogen Storage expertise to hydrogen storage, fuel cells, and system integration issues ­Novel membranes and other

337

The Propagation of Tides up Rivers With Special Considerations on the Upper Saint Lawrence River  

NASA Astrophysics Data System (ADS)

The hydrodynamics of rivers affected by tides is dominated by the damping and the distortion induced by quadratic bottom friction. A compact and accurate approximation to the deceleration term, standing for the frictional effect, allows the retention of the concept of harmonics and separation of the time and space variations. It then becomes possible to explain, in terms of basic physics, the transformation of the tide from the estuary, to the zone where it becomes extinct. The theoretical reasoning is supported by pertinent observations collected in the Saint Lawrence river; numerical relations are derived to demonstrate the existence of non-linear effects and to quantitatively link various relevant physical parameters. This analysis, in turn, helps outline approaches to improve the tide predictions in such rivers which happen to have such great economic and strategic importance.

Godin, G.

1999-03-01

338

Turbidity and sediment transport in a muddy sub-estuary  

Microsoft Academic Search

Sub-estuaries, i.e. tidal creeks and also larger estuaries that branch off the stem of their main estuary, are commonplace in many estuarine systems. Their physical behaviour is affected not only by tributary inflows, winds and tides, but also by the properties and behaviour of their main estuary. Measurements extending over more than an annual cycle are presented for the Tavy

R. J. Uncles; J. A. Stephens

2010-01-01

339

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 ...

340

St. Louis  

Cancer.gov

The Psychology Department of St. Louis Children’s Hospital at Washington University Medical Center is pleased to recruit for a second Postdoctoral Fellowship position in Pediatric Psychology beginning September 2014. With a balance of in-depth and broad based training experiences, this one-year program will prepare fellows to work independently in the practice of pediatric psychology.

341

Mercury gas exchanges over selected bare soil and flooded sites in the bay St. François wetlands (Québec, Canada)  

Microsoft Academic Search

In order to evaluate and understand the mercury gas exchange processes in fluvial wetlands, related researches were initiated in a St. Lawrence River wetland (Bay St. François, Qué., Canada). Mercury fluxes were measured using dynamic flux chamber methods, coupled with an automatic mercury vapor analyzer (namely, Tekran, Model 2537A). Mercury air–surface gas exchanges as well as meteorological conditions were measured

Laurier Poissant; Martin Pilote; Philippe Constant; Conrad Beauvais; Hong H Zhang; Xiaohong Xu

2004-01-01

342

BBC News Special Report: The Lawrence Inquiry  

NSDL National Science Digital Library

In 1993, 18-year-old Stephen Lawrence was stabbed to death in London in a racially motivated attack. Lawrence's killers have not been successfully prosecuted, and, as this report released by the UK Home Office on February 24 reveals, the London police inquiry into the crime displayed "professional incompetence and institutional racism." Undoubtedly the most infamous racial murder in recent British history, Lawrence's death, the police investigation, and the far-reaching government inquiry which followed are being regarded as a milestone in British race relations, inspiring new private and government initiatives to improve relations as well as proposals for extensive changes in the UK policing and judicial systems. This BBC special report on the Inquiry offers an interactive chronology of events, profiles of key figures, analysis and reaction, archived articles, and the latest news.

343

US Environmental Protection Agency: National Estuary Program  

NSDL National Science Digital Library

Established in 1987 by amendments to the Clean Water Act and administered by the Environmental Protection Agency's Office of Wetlands, Oceans, and Watersheds (OWOW), the National Estuary Program (NEP) identifies, restores and protects estuaries along the coasts of the United States. Unlike the traditional regulatory approaches to environmental protection, the NEP targets a wide range of issues and engages local communities in the process. At the site users can find descriptions of the NEP, specific NEP projects, estuaries involved in the NEP (including location, size, presence of threatened and endangered species, major habitat types, etc.), a current awareness section, links to related sites, and the full text of NEP's newsletter, Coastlines.

344

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...

345

Lattice Boltzmann Hydrodynamic and Transport Modeling of Everglades Mangrove Estuaries  

NASA Astrophysics Data System (ADS)

Lattice Boltzmann methods are being developed and applied to simulate groundwater and surface water flows, and heat, solute, and particle transport. Their ability to solve Navier-Stokes, St. Venant, or Darcy equations with closely coupled solute transport and density-dependent flow effects in geometrically complex domains is attractive for inverse modeling of tracer release data and forward modeling of carbon transport in mangrove estuaries under various future conditions. Key physical processes to be simulated include tidal cycles, storm surge, sea level change, variable upstream stage, subsurface groundwater inputs, and precipitation/recharge and their effects on estuary salinity and carbon transport in the estuaries and groundwater beneath the mangroves. Carbon sources and storage in the aquifer and exchanges at the mangrove-estuary interface and carbon transformations in the water column also need to be simulated. Everglades tidal mangrove estuaries are characterized by relatively high velocity (approaching 1 m s-1) tidal flows. The channels are generally less than 2 m in depth. Tidal fluctuations approach 2 m leading to significant areas of periodic inundation and emergence of oyster beds, shell beaches, mangrove root masses, and sandy beaches. Initial models are two-dimensional, although a three-dimensional model explicitly incorporating bathymetry, density-dependent flow, and wind-driven circulation could be developed. Preliminary work highlights some of the abilities of early models. A satellite image of a 64-km2 area surrounding a CO2 flux tower is used to provide the model geometry. Model resolution is 15 m per grid node. A sinusoidal tidal stage variation and constant, high salinity are applied to the Gulf side of the model while a constant stage (corresponding to mean tide), zero salinity boundary is applied on the inland side. The Navier-Stokes equations coupled with the advection-diffusion equation are solved in the open channels. The mangrove areas are simulated as a porous medium, where transport is controlled by the advection-dispersion equation. As expected, incoming tides carry salinity up the channels and outgoing tides tend to flush the salinity from the channels. Salinity also invades the groundwater beneath the mangroves, which then contributes salinity back to the channel during outgoing tides. Although some large-scale aspects of the tidal flows are captured in these preliminary simulations, the current simulations are at Reynolds numbers smaller than those that characterize the real flows. More realistic simulations would require much higher resolution and have to be implemented on large-scale parallel computing platforms possibly using sub-grid turbulence models. Tracer data from experimental releases of SF6 will be used to estimate the parameters controlling transport in the estuary via inverse modeling with the parameter estimation code PEST. SF6 undergoes volatilization from the water column and is therefore a reasonable surrogate for air-sea CO2 gas exchange in the modeling framework. The parameters estimated from the tracer test inversion will be used in predictive modeling of the effects of sea level variations on salinity and carbon transport.

Sukop, M. C.; Engel, V.

2010-12-01

346

Plankton dynamics along a 180 km reach of the Saint Lawrence River from its headwaters in Lake Ontario  

Microsoft Academic Search

We test the hypothesis that phytoplankton biomass decrease upon entry into the St. Lawrence River from headwaters in Lake\\u000a Ontario is attributable to a range of causal factors including, decreased photosynthetic fitness due to turbulence, cell loss\\u000a due to increased flocculation and subsequent sedimentation, decreases in nutrients, and loss due to grazing. In order to test\\u000a this, changes in phytoplankton

Michael R. Twiss; Carmen Ulrich; Stefanie A. Kring; Jessica Harold; Matthew R. Williams

2010-01-01

347

Life History and Population Characteristics of Striped Bass in Atlantic Canada  

Microsoft Academic Search

Populations of striped bass Morone saxatilis occur in three regions of Atlantic Canada: the St. Lawrence River and estuary in Quebec; the Gulf of St. Lawrence from Chaleur Bay through Northumberland Strait; and rivers in New Brunswick and Nova Scotia draining into the Bay of Fundy. At least nine rivers are known or believed to sustain spawning populations: the St.

Roger A. Rulifson; Michael J. Dadswell

1995-01-01

348

Assessing the susceptibility of two UK estuaries to nutrient enrichment  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

349

Restaurant Growth in Lawrence, Kansas, 1950 to 2007  

E-print Network

?s, Chili?s, Old Chicago 63 3.15 Fre State Brewing Co. 68 4.1 Lawrence Restaurants, 2000 72 vii 4.2 Lawrence Restaurants, 2000 Insets 73 4.3 Mas. Stret Deli 74 4.4 West 23 rd Stret, 1977 74 4.5 est 23 rd Stret, 2008 74 4.6 Lawrence Ethnic...

Brackhan, Jennifer L.

2009-01-22

350

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...

351

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...

352

Copper speciation in estuaries and coastal waters  

E-print Network

The goals of this dissertation are to better understand the sources and the Cu binding ability of ligands that control Cu toxicity in estuaries and harbors, where elevated Cu concentrations have caused documented toxic ...

Kogut, Megan Brook, 1972-

2002-01-01

353

A Shared Object Hierarchy Lawrence A. Rowe  

E-print Network

, the object hierarchy is not shared. Moreover, the object hierarchy is usually restricted to main memory. The LOOM system stored object hierarchies in secondary memory [KaK83], but it did not allow object sharingA Shared Object Hierarchy Lawrence A. Rowe Computer Science Division - EECS University

California at Irvine, University of

354

LAWRENCE S. MOSS Department of Mathematics  

E-print Network

LAWRENCE S. MOSS Department of Mathematics Indiana University Bloomington, Indiana 47405 lsm children. Education 1984: Ph.D., Mathematics, UCLA Ph.D. Dissertation: Power Set Recursion Thesis Advisor: Yiannis N. Moschovakis 1981: M.A., Mathematics, UCLA 1979: B.A., Mathematics, UCLA Academic Employment

Indiana University

355

ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY  

E-print Network

LBNL 59620 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Ventilation Behavior and Household, or the State of California. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as actual or implied endorsement of such products. The ARB

356

Struggle for the Soul: John Lawrence Childs  

ERIC Educational Resources Information Center

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…

Stallones, Jared

2010-01-01

357

Radiological Work Authorization Lawrence Berkeley National Laboratory  

E-print Network

Radiological Work Authorization Lawrence Berkeley National Laboratory Environment, Health and is not authorized by this Radiological Work Authorization (RWA). If work in fields greater than 100 mrem/h at 30 cm is necessary, a separate Radiological Work Permit (RWP) is required. Experiment Description (cont

Knowles, David William

358

Lawrence E. Carlson Professor of Mechanical Engineering  

E-print Network

Education, American Society of Mechanical Engineers, pp. 31-33. Solar Stirling Engine 2Cam Rock ClimbingPortfolio Lawrence E. Carlson Professor of Mechanical Engineering Founding Co-Director, Integrated Teaching and Learning Program and Laboratory University of Colorado at Boulder #12;ENGINEERING EDUCATION

Carlson, Lawrence E.

359

ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY  

E-print Network

efficiencies (AFUE ratings) greater than 90%. However, the fans that are used to move the air in forced airLBNL 53606 ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Improving Air Handler Efficiency Laboratory is an equal opportunity employer. 2 #12;IMPROVING AIR HANDLER EFFICIENCY IN RESIDENTIAL HVAC

360

LINFENG RAO Lawrence Berkeley National Laboratory  

E-print Network

1 LINFENG RAO Lawrence Berkeley National Laboratory (tel) 510-486 5427, (fax) 510-486 5596, E-mail: LRao@lbl.gov Journal Articles (2000 -) L. Rao; Thermodynamics of actinide complexation in solution. Rev., 36 (6), 881-892 (2007). G. Tian, L. Rao, A. Oliver; Symmetry and optical spectra: a "silent" 1

Rao, Linfeng

361

Estuaries and coastal waters need help  

Microsoft Academic Search

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,

Howard Levenson

1987-01-01

362

Who's Who in the University of Kansas Libraries: Lawrence Campus 2004  

E-print Network

, Serials Manager-RCL Case, Susan, Biological/Environ.Sci.Lib.-Anschutz Chapman, Kerry, LA Ill-Cataloging I'm a life-long resident of Lawrence. Before joining the library, I worked as a bulldozer operator, a surveyor's assistant and as a proofreader... me busy. Love to read and work with my hands. Mehmedovic, Jennifer, Asst to VP/Info Svc,223 ST Mellenbruch, Jennifer, Ext. Asst.-RCL Mercer, Holly, Metadata Coordinator-Cataloging Meyers, Amy Jo, LAI-Watson Reference Mi-Mo Miller, John, Llll...

2004-01-01

363

Estuaries.  

ERIC Educational Resources Information Center

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…

Awkerman, Gary L.

364

ESTIMATING THE CONDITION OF GULF OF MEXICO ESTUARIES: NATIONAL COASTAL ASSESSMENT AND NATIONAL ESTUARY PROGRAM  

EPA Science Inventory

Estuaries in the Gulf of Mexico have been monitored since 1991 to determine the condition of water, sediment, and biota. More recently, through the National Coastal Assessment (NCA), U.S. EPA has provided a comprehensive estimate of the condition of U.S. estuaries, including a re...

365

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

PubMed

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

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

2007-11-01

366

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...

367

Transport of particulate organic material between salt marsh and estuary  

Microsoft Academic Search

The macrophyte production and the transport of particulate organic matter between march and adjacent estuary have been investigated for a 30 ha salt marsh along the Oosterschelde estuary, The Netherlands.

W. J. Wolff

1979-01-01

368

Manassas St. Monroe Ave.  

E-print Network

. Washington A Adams Ave. Mid-South Hospital LeBonheur Children'sMedical Center MemphisandShelby County St. DudleySt. Monroe Ave. Madison Ave. DunlapSt. HospitalSt. Je erson Ave. ManassasSt. e. ve and Marketing Department Writing, Editing TIM BULLARD, MA Design, Layout and AMBER CARTER Photography SHEILA

Cui, Yan

369

Dr. Tom Lawrence: a life in chiropractic  

PubMed Central

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

Keating, Joseph C

2005-01-01

370

Lawrence Livermore National Laboratory Summer Employment Summary  

SciTech Connect

This document will serve as a summary of my work activities as a summer employee for the Lawrence Livermore National Laboratory (LLNL). The intent of this document is to provide an overview of the National Ignition Facility (NIF) project, to explain the role of the department that I am working for, and to discuss my specific assigned tasks and their impact on the NIF project as a whole.

Wilson, A J

2002-08-06

371

Lawrence Berkeley Laboratory 1993 Site Environmental Report  

SciTech Connect

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.

Not Available

1994-05-01

372

Lawrence Livermore National Laboratory earthquake safety program  

Microsoft Academic Search

Within three minutes on the morning of January 24, 1980, an earthquake and three aftershocks, with Richter magnitudes of 5.8, 5.1, 4.0, and 4.2, respectively, struck the Livermore Valley. Two days later, a Richter magnitude 5.4 earthquake occurred, which had its epicenter about 4 miles northwest of the Lawrence Livermore National Laboratory (LLNL). Although no one at the Laboratory was

Freeland

1984-01-01

373

Life sciences: Lawrence Berkeley Laboratory, 1988  

SciTech Connect

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.

Not Available

1989-07-01

374

The Estuary Guide. Level 3: High School. Draft.  

ERIC Educational Resources Information Center

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…

Alexander, Glen; And Others

375

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...

376

Monitoring and Managing Contamination in the San Francisco Estuary  

E-print Network

relevant. Introductory information on what is measured by the RMP and why can be found in the 1998 Pulse2000Update Monitoring and Managing Contamination in the San Francisco Estuary of the Estuary Pulse, California. The Pulse of the Estuary is one of three Regional Monitoring Program reporting products for 2000

377

Environmental flow assessments for transformed estuaries  

NASA Astrophysics Data System (ADS)

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.

Sun, Tao; Zhang, Heyue; Yang, Zhifeng; Yang, Wei

2015-01-01

378

Teaching Ocean Sciences in the 21st Century Classroom: Lab to Classroom Videoconferencing  

Microsoft Academic Search

Teaching Ocean Science in the 21st Century Classroom (TOST) is a Center for Ocean Sciences Education Excellence (COSEE CA) initiative aimed at developing and disseminating technology-based instructional strategies, tools and ocean science resources for both formal and informal science education. San Diego Unified School District (SDUSD), Scripps Institution of Oceanography (SIO) and the Lawrence Hall of Science (LHS) have established

C. L. Peach; W. Gerwick; L. Gerwick; M. Senise; C. S. Jones; K. Malloy; A. Jones; E. Trentacoste; J. Nunnery; T. Mendibles; D. Tayco; L. Justice; R. Deutscher

2010-01-01

379

Lawrence and His Laboratory: A Historian's View of the Lawrence Years  

NSDL National Science Digital Library

Lawrence Berkeley Laboratory celebrated its 65th anniversary, and created this web site as a tribute to its founder. Ernest Orlando Lawrence, who invented the cyclotron, opened the way to "a Golden Age of particle physics and revolutionary discoveries about the nature of the universe." The story was originally told by the lab's public information department in 1981. All in all, this site provides a personal look into one of the foremost physics labs in the world, at a time when its discoveries were literally shaking the world.

Heilbron, J.L.

1981-01-01

380

Modeling tidal distortion in the Ogeechee Estuary  

NASA Astrophysics Data System (ADS)

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.

Bruder, Brittany; Bomminayuni, Sandeep; Haas, Kevin; Stoesser, Thorsten

2014-10-01

381

Decadal mercury trends in San Francisco Estuary sediments.  

PubMed

Monitoring sediment quality and total mercury concentrations over the period 1993-2001 at 26 stations in San Francisco Estuary has shown the seasonal cycling of mercury sediment concentrations, as well as a significant (P < 0.05) decrease in those concentrations at eight stations across the estuary. This decrease in sediment mercury concentrations is attributed to the transport of relatively cleaner sediment to the estuary from the Sacramento River and San Joaquin River watersheds. Despite the decreases observed in some parts of the estuary, no corresponding trend has been found in concurrent studies on sport fish and bivalves in the estuary. PMID:17161835

Conaway, Christopher H; Ross, John R M; Looker, Richard; Mason, Robert P; Flegal, A Russell

2007-09-01

382

East Broad St University Dr  

E-print Network

St Henderson St ncack Ave Reese St HarrisSt ChurchSt Dearing St Waddell St Broad St CollegeAve South Cemetery Aderhold Butts-Mehre Brumby Russell Hill PoultryScience Barrow Founders Memorial Garden Visual Studies Lumpkin House Marine Science Physical Education South CampusParking Deck Coliseum Parking Deck

Scott, Robert A.

383

RIVERINE ESTUARY CLASSIFICATION FOR THE SAKE OF ENVIRONMENTAL CONSERVATION  

NASA Astrophysics Data System (ADS)

The environment of riverine estuaries is characterized by many factors including tidal oscillation, river flow and morphology, and the combination of these factors makes each estuary unique in its environment. However, there are similarities among some estuaries. We have tried to classify Japan’s 109 riverine estuaries based on physical environmental factors like tidal oscillation, wave energy, and high and low river flow. 109 riverine estuaries were divided into 5 classifications. Fish species monitoring data have also been analyzed to categorize riverine estuaries and the results were compared to 5 classifications divided by physical factors. Since our physical and biological classification both seemed to be related to the salinity of the estuary, these two classifications showed fair conformity.

Kishida, Hiroyuki; Amano, Kunihiko; Oonuma, Katsuhiro; Endoh, Maremi

384

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...

385

A Bioenergetics Modeling Evaluation of Top-down Control of Ruffe in the St. Louis River, Western Lake Superior  

Microsoft Academic Search

Ruffe (Gymnocephalus cernuus), were accidentally introduced into the St. Louis River estuary, western Lake Superior, in the mid 1980s and it was feared that they might affect native fish through predation on eggs and competition for forage and habitat. In an effort to control the abundance of ruffe and limit dispersal, a top-down control strategy using predators was implemented in

Kathleen R. Mayo; James H. Selgeby; Michael E. McDonald

1998-01-01

386

Lawrence Berkeley Laboratory 1994 site environmental report  

SciTech Connect

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.

NONE

1995-05-01

387

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...

388

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...

389

BATHYMETRY FOR ALBEMARLE AND PAMLICO ESTUARIES, NC  

EPA Science Inventory

Bathymetry for the Albemarle and Pamlico Estuaries obtained from National Oceanographic and Atmospheric Administration-National Ocean Service (NOAA-NOS). See the metadata within the files from NOAA-NOS for more details and warnings concerning merging with US Geolgoical Survey Dig...

390

Padilla Bay: The Estuary Guide. Level 2.  

ERIC Educational Resources Information Center

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…

Friesem, Judy; Lynn, Valerie, Ed.

391

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...

392

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 ...

393

Estuaries and Tidal Marshes. Habitat Pac.  

ERIC Educational Resources Information Center

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…

Fish and Wildlife Service (Dept. of Interior), Washington, DC.

394

Adsorption processes and hydrodynamic conditions in estuaries  

Microsoft Academic Search

In estuaries the decrease in adsorption of dissolved metals to suspended particulate matter is counteracted by more or less simultaneous increases in turbidity, pH and by the formation of new particulate matter. Experiments on the behaviour of cadmium and zinc under artificial estuarine conditions show that the processes in the region of 0–5% chlorinity are most important.

W. Salomons

1980-01-01

395

Kaua'i: Streams and Estuaries.  

ERIC Educational Resources Information Center

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…

Hawkins, John, Ed.; Murakami, Colleen, Ed.

396

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...

397

Introduction In many estuaries of North America,  

E-print Network

shoreline flats. The principal mat-form- ing types are sea lettuce, Ulva lactuca (Fig. 1), Enteromorpha spp., Gracilaria spp., and Cladophora spp. Few macroin- Removal of Sea Lettuce, Ulva spp., in Estuaries to Improve--Mats (biomasses) of mac- roalgae, i.e. Ulva spp., Enteromorpha spp., Graciolaria spp., and Cladophora spp., have

398

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,...

399

TAMPA BAY ESTUARY PROGRAM, 2004 IMPLEMENTATION REVIEW  

EPA Science Inventory

The Tampa Bay Estuary Program and its partners have made measurable progress toward implementation of the adopted CCMP goals. Progress has occurred in the following areas: bay habitats, with an increase in seagrass, estuarine habitat restoration and preservation; water and sedime...

400

Pressure safety program Lawrence Livermore National Laboratory  

SciTech Connect

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.

Borzileri, C.; Traini, M.

1992-10-01

401

Math 530: Topics in Geometry Winter Term, 2013, Lawrence University  

E-print Network

.corry@lawrence.edu Webpage: www.lawrence.edu/fast/corrys Texts: R. Hartshorne, Geometry: Euclid and Beyond (Springer) D. Densmore (ed.), Euclid's Elements (Green Lion Press) 1 Overview This course will be divided into three parts, each labeled by the name of a famous mathematician: Euclid, Hilbert, Poincar´e. 1.1 Euclid We

Corry, Scott

402

Thank you to our sponsors Thinking about healthy estuaries in the Year 2111 and  

E-print Network

made in the catchment are disconnected from estuary health #12 estuaries? · Swan-Canning Estuary: 90% of people agreed or strongly agreed that the rivers are a really important part of Perth's landscape, 97% that natural areas

403

76 FR 8345 - Endangered and Threatened Species; Recovery Plan Module for Columbia River Estuary Salmon and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Species; Recovery Plan Module for Columbia River Estuary Salmon and Steelhead AGENCY: National...availability; recovery plan module for Columbia River estuary salmon and steelhead...announces the adoption of the Columbia River Estuary Endangered Species Act...

2011-02-14

404

75 FR 17382 - Small Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Water...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Incidental to Specified Activities; Russian River Estuary Water Level Management Activities...Level B harassment, incidental to Russian River Estuary (Estuary) water level management...activities at the mouth of the Russian River, Jenner, CA. DATES: Effective...

2010-04-06

405

San Francisco Estuary Regional Monitoring Program for Trace Substances A Review of Urban Runoff Processes  

E-print Network

San Francisco Estuary Regional Monitoring Program for Trace Substances A Review of Urban Runoff Pathways and Loadings Workgroup (SPLWG) San Francisco Estuary Regional Monitoring Program for Trace and Loading Workgroup. San Francisco Estuary Regional Monitoring Program for Trace Substances. SFEI

406

Historical changes in the Columbia River Estuary  

NASA Astrophysics Data System (ADS)

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.

Sherwood, Christopher R.; Jay, David A.; Bradford Harvey, R.; Hamilton, Peter; Simenstad, Charles A.

407

Small estuary, big port - progress in the management of the Stour-Orwell Estuary system  

NASA Astrophysics Data System (ADS)

Management of port development is increasingly challenging because of the competitive requirement for deeper channels and because of the need to preserve important coastal wetlands which function as both habitat and flood defence. This paper describes the management of the Stour/Orwell Estuary system, Eastern England, an estuary system which has experienced considerable development and morphological change. The estuary is internationally important for its wetland bird populations and the intertidal areas of the estuary system are protected under European legislation. It is also the location of the Port of Felixstowe. In 1998/2000 the approach channel to the Port of Felixstowe was deepened from -12.5 mCD to -14.5 mCD. This paper describes the effects of the approach channel deepening, the approach taken to identifying the potential impact to intertidal habitat resulting from the deepening, the sediment recycling implemented as mitigation to prevent increased loss of habitat and the subsequent response of the estuary system to this intervention.

Spearman, Jeremy; Baugh, John; Feates, Nigel; Dearnaley, Mike; Eccles, Dan

2014-10-01

408

Geographic signatures of North American West Coast estuaries  

Microsoft Academic Search

West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from\\u000a large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms,\\u000a and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable\\u000a shellfish, waterfowl and marine birds,

Robert Emmett; ROBERTO LLANSO ´; Jan Newton; Ron Thom; Michelle Hornberger; Cheryl Morgan; Colin Levings; Andrea Copping; Paul Fishman

2000-01-01

409

Modelling Pb and Cd dynamics in the Seine estuary  

Microsoft Academic Search

The Seine estuary (France) is currently one of the world’s most contaminated estuaries, due in particular to its high cadmium\\u000a and lead content. Proper understanding of contaminant transfer, transformation and retention mechanisms throughout the estuary\\u000a and up to the adjacent marine zone require a range of studies involving data collections, experiments, and modeling tool.\\u000a A multivariable transport model (SiAM-3D) was

B. Thouvenin; J. L. Gonzalez; J. F. Chiffoleau; B. Boutier; P. Le Hir

2007-01-01

410

Adaptive Optics at Lawrence Livermore National Laboratory  

SciTech Connect

Adaptive optics enables high resolution imaging through the atmospheric by correcting for the turbulent air's aberrations to the light waves passing through it. The Lawrence Livermore National Laboratory for a number of years has been at the forefront of applying adaptive optics technology to astronomy on the world's largest astronomical telescopes, in particular at the Keck 10-meter telescope on Mauna Kea, Hawaii. The technology includes the development of high-speed electrically driven deformable mirrors, high-speed low-noise CCD sensors, and real-time wavefront reconstruction and control hardware. Adaptive optics finds applications in many other areas where light beams pass through aberrating media and must be corrected to maintain diffraction-limited performance. We describe systems and results in astronomy, medicine (vision science), and horizontal path imaging, all active programs in our group.

Gavel, D T

2003-03-10

411

Public attitudes toward Lawrence Livermore National Laboratory  

SciTech Connect

Charlton Research Company is pleased to present the following summary of findings report for research conducted under contract with Lawrence Livermore National Laboratory. This section provides a brief introduction to the specifications of the study, and a guide to the organization of this report. Although the most sophisticated procedures have been used to collect and analyze the information presented here, it must be remembered that qualitative and quantitative research are not predictions. They are designed to measure public opinion within identifiable statistical limits or accuracy at specific points in time. This research is in no way a prediction of opinion or action at any future point in time. Among the topics covered in the surveys are: openness; National Laboratory; health hazards; radioactivity; uses of plutonium; hazardous waste; groundwater pollution; nuclear weapons; Ballistic Missile Defense; and earthquakes.

Not Available

1990-05-01

412

Lawrence Berkeley Laboratory Affirmative Action Program. Revised  

SciTech Connect

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.

NONE

1995-06-01

413

Volume II, Chapter 3 Columbia River Estuary Tributaries  

E-print Network

.......................................................................................................... 3-8 3.5.5 Substrate & Sediment into broad estuaries and then into Baker Bay. Their basins have a combination of sedimentary and volcanic

414

St. John's wort  

MedlinePLUS

... marked by excessive physical activity and impulsive behavior. Schizophrenia: St. John’s wort might bring on psychosis in some people with schizophrenia. Alzheimer’s disease: There is concern that St. John’s ...

415

Impact of climate change on Gironde Estuary  

NASA Astrophysics Data System (ADS)

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.

Laborie, Vanessya; Hissel, François; Sergent, Philippe

2014-05-01

416

Geomorphological study of sundarban deltaic estuary  

Microsoft Academic Search

Summary  Study of landforms in Sundarbans deltaic estuary is necessary in regular basis due to its importance and impact on ecology,\\u000a climate and economy. Remote sensing has proved as an important tool to study this. Multi-temporal satellite data helps to\\u000a delineate the various geomorphic classes in different time domain and also provide inputs to study the coastal erosion and\\u000a accretion. Finer

Dipnarayan Ganguly; Anirban Mukhopadhyay; Rahul Krishna Pandey; Debasish Mitra

2006-01-01

417

Tidal exchange between a freshwater tidal marsh and an impacted estuary: the Scheldt estuary, Belgium  

NASA Astrophysics Data System (ADS)

Tidal marsh exchange studies are relatively simple tools to investigate the interaction between tidal marshes and estuaries. They have mostly been confined to only a few elements and to saltwater or brackish systems. This study presents mass-balance results of an integrated one year campaign in a freshwater tidal marsh along the Scheldt estuary (Belgium), covering oxygen, nutrients (N, P and Si), carbon, chlorophyll, suspended matter, chloride and sulfate. The role of seepage from the marsh was also investigated. A ranking between the parameters revealed that oxygenation was the strongest effect of the marsh on the estuarine water. Particulate parameters showed overall import. Export of dissolved silica (DSi) was more important than exchange of any other nutrient form. Export of DSi and import of total dissolved nitrogen (DIN) nevertheless contributed about equally to the increase of the Si:N ratio in the seepage water. The marsh had a counteracting effect on the long term trend of nutrient ratios in the estuary.

Van Damme, Stefan; Frank, Dehairs; Micky, Tackx; Olivier, Beauchard; Eric, Struyf; Britta, Gribsholt; Oswald, Van Cleemput; Patrick, Meire

2009-11-01

418

Linking Cognitive Neuroscience and Molecular Genetics: New Perspectives from Williams Syndrome Ursula Bellugi and Marie St. George (Eds.)  

E-print Network

Linking Cognitive Neuroscience and Molecular Genetics: New Perspectives from Williams Syndrome in Williams Syndrome Debra L. Mills, Twyla D. Alvarez, Marie St. George, and Lawrence G. Appelbaum University of Oregon Abstract & Williams Syndrome (WMS) is a genetically based disorder characterized by pronounced

419

Effets de la température sur la croissance de deux algues vertes du fleuve St-Laurent, secteur de Gentilly, Québec  

Microsoft Academic Search

Two abundant phytoplankters from the St-Lawrence river: Scenedesmus spinosus Chodat 1913 and Pediastrum boryanum (Turp.) Menegh (Chlorophyta, Chlorococca) were sampled, isolated and cultured in monospecific culture. Growth responses were measured after acclimation to different temperatures and after thermal shock treatments.

Y. Thibault; R. Couture

1982-01-01

420

Freshwater, tidal and wave influences on a small estuary  

NASA Astrophysics Data System (ADS)

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.

Uncles, R. J.; Stephens, J. A.; Harris, C.

2014-10-01

421

Lawrence Livermore National Laboratory Environmental Report 2010  

SciTech Connect

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.

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

422

Lawrence Berkeley National Laboratory JAMES E. HOUSEWORTH, Ph.D.  

E-print Network

and transport, with applications to nuclear waste disposal and petroleum recovery. Experience Summary: Dr assessment and site characterization efforts at Yucca Mountain, Nevada, DOE's previously proposed disposal nuclear power plants and municipal sewage effluent. Professional History: 2000 to Present Lawrence

Ajo-Franklin, Jonathan

423

Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence Brown  

E-print Network

1 Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence investigate a classical non-parametric Poisson empirical Bayes estimation problem,!( )= EG R ",!( )( ). The Bayes procedure is !G y( )= E " Y = y( ) (with the conditional

Brown, Lawrence D.

424

Status report to ERDA Nuclear Data Committee. [Lawrence Livermore Laboratory  

SciTech Connect

The status of nuclear research at Lawrence Livermore Laboratory is presented in the following areas: standards; neutron data applications; data compilation program; basic physics; and facilities. Three papers with significant information are listed separately by title. (RWR)

Anderson, J. D.; Browne, J. C.

1976-04-09

425

Personal Property Policy Manual Lawrence Berkeley National Laboratory  

E-print Network

Personal Property Policy Manual Issued by Lawrence Berkeley National Laboratory Property Management Group May 1, 2013 #12;May 1, 2013 2 Contents Overview of Property Management Policies................................................................................................4 1.0 General Property Policies

426

LIMNETIC LARVAL FISH OF THE MAUMEE AND SANDUSKY RIVER ESTUARIES  

EPA Science Inventory

A total of 17 taxa were collected in the Maumee River estuary during sampling periods in 1975, 1976, and 1977. A total of 11 taxa were collected from the Sandusky River estuary in 1976. Gizzard shad/alewife, Dorosoma cepedianum/Alosa pseudoharengus, white bass/white perch, Morone...

427

Contaminant Modeling in San Francisco Bay: Lessons from Other Estuaries  

E-print Network

Contaminant Modeling in San Francisco Bay: Lessons from Other Estuaries Dr. Joel Baker Director, UW chemical contaminants in estuaries · Approaches and common traits of estuarine contaminant models · What is missing? · Final thoughts #12;Outline · Utility and challenges of modeling chemical contaminants

428

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...

429

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...

430

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...

431

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...

432

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...

433

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...

434

Annual environmental monitoring report of the Lawrence Berkeley Laboratory  

SciTech Connect

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.

Schleimer, G.E.; Pauer, R.O. (eds.)

1990-08-01

435

Lawrence hydroelectric project: resurrection of a low-head dam  

SciTech Connect

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.

Not Available

1982-04-01

436

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...

437

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...

438

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary  

E-print Network

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary Daniel J. Bottom NOAA management efforts in the Columbia River estuary on behalf of salmon: (1) the estuary is irrelevant to conservation because fresh water conditions limit salmon production; and (2) the estuary is a threat

439

A hybrid approach to estimate chromophoric dissolved organic matter in turbid estuaries from  

E-print Network

A hybrid approach to estimate chromophoric dissolved organic matter in turbid estuaries from to derive CDOM absorption coefficient at 443 nm (ag(443), m-1 ) in a turbid estuary (Tampa Bay) from MODIS discharge. Testing of the approach over another turbid estuary (Chesapeake Bay, the largest estuary in the U

Meyers, Steven D.

440

PECONIC ESTUARY: AN INVENTORY OF SUBMERGED AQUATIC VEGETATION AND HARDENED SHORELINES FOR THE PECONIC ESTUARY, NEW YORK  

EPA Science Inventory

Executive Summary The Peconic Estuary Program (PEP) is interested in the extent of eelgrass and other submerged aquatic vegetation and in documenting changes in the shorelines of the Peconic Estuary. The Suffolk County Department of Health Services' Office of Ecology provided fun...

441

Delaware Estuary situation reports. Emergency response: How do emergency management officials address disasters in the Delaware Estuary  

Microsoft Academic Search

From hurricanes and other natural threats to oil spills and other manmade emergencies, the Delaware Estuary has experienced a variety of disasters over the years. The toll that these events take on the estuary and those who live on its shores depends largely upon the degree of emergency preparedness, speed of response, and effectiveness of recovery operations. In Emergency Response:

Sylves

1991-01-01

442

Decline of Canada geese ( Branta canadensis ) and common goldeneye ( Bucephala clangula ) associated with a collapse of eelgrass ( Zostera marina ) in a Nova Scotia estuary  

Microsoft Academic Search

.   Mean numbers of migrant Canada geese (Branta canadensis) in Antigonish Harbour in the southern Gulf of St. Lawrence (Canada) during October to December were similar (approx. 450–500\\u000a birds) for the period 1998–2000. Similarly, during this period, geese used two foraging sites. However, in 2001, the average\\u000a number of birds decreased by half and the primary foraging sites were used

Norman R. Seymour; Anthony G. Miller; David J. Garbary

2002-01-01

443

Petrology/Geochemistry/Mineralogy/Structure of Shear zones in St. Lawrence County  

NSDL National Science Digital Library

These rocks were collected from outcrops frequented by structural geology field trips. CCM 42 is from the town of Clare, CCM 43 is from Russell; although labeled CCM, neither is from the Carthoage Colton Mylonite Zone, but both are from shear zones. DEK is from the world famous DeKalb anticline. In this lab we try to pull together material from petrology, geochemistry, mineralogy and structure.

Robert Badger

444

Estimating whale density from their whistling activity: Example with St. Lawrence beluga  

Microsoft Academic Search

A passive acoustic method is developed to estimate whale density from their calling activity in a monitored area. The algorithm is applied to a loquacious species, the white whale (Delphinapterus leucas), in Saguenay fjord mouth near Tadoussac, Canada, which is severely affected by shipping noise. Beluga calls were recorded from cabled coastal hydrophones deployed in the basin while the animal

Y. Simard; N. Roy; S. Giard; C. Gervaise; M. Conversano; N. Ménard

2010-01-01

445

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Management, U.S. Coast Guard Sector Buffalo; telephone 716- 843-9343, email SectorBuffaloMarineSafety...Ogdensburg, NY. The Captain of the Port Buffalo has determined that fireworks launched...hazards in mind, the Captain of the Port Buffalo has determined that this temporary...

2012-07-20

446

POTASSIC MAGMATISM ON ST. LAWRENCE ISLAND, ALASKA, AND CAPE DEZHNEV, NORTHEAST RUSSIA  

E-print Network

a syenite pluton at Cape Dezhnev on the Chukotka Peninsula of Russia. These geochemical data are used of larger-volume subalkaline magmatism between 110 and 100 Ma (and possibly younger). A nepheline syenite but less potassic than the syenites. It has Nd of -0.35 and initial 87Sr/86Sr of 0.7063, and a biotite from

Amato, Jeff

447

POTASSIC MAGMATISM ON ST. LAWRENCE ISLAND, ALASKA, AND CAPE DEZHNEV, NORTHEAST RUSSIA  

E-print Network

a syenite pluton at Cape Dezhnev on the Chukotka Peninsula of Russia. These geo-chemical data are used of larger-volume subalkaline magmatism between 110 and 100 Ma (and possibly younger). A nepheline syenite but less potassic than the syenites. It has Nd of -0.35 and initial 87Sr/86Sr of 0.7063, and a biotite from

Toro, Jaime

448

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

SciTech Connect

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.

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

1992-03-01

449

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

SciTech Connect

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.

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

2005-02-02

450

Water Resources Data, Pennsylvania, Water Year 2002, Volume 3. Ohio and St. Lawrence River Basins  

USGS Publications Warehouse

Water-resources data for the 2002 water year for Pennsylvania consists of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 3 contains (1) discharge records for 60 continuous-record streamflow-gaging stations, 5 partial-record stations, and 13 special study and miscellaneous streamflow sites; (2) elevation and contents records for 11 lakes and reservoirs; (3) water-quality records for 23 gaging stations and 33 ungaged streamsites; (4) water-level records for 23 network observation wells; (5) water-quality analyses at 28 special study ground-water wells; and (6) miscellaneous water-level measurements at 31 special study ground-water wells. Site locations are shown in figures throughout the report. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 1 and 2, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

Siwicki, Raymond W.

2003-01-01

451

Water resources data, Pennsylvania, water year 2003; volume 3. Ohio and St. Lawrence River basins  

USGS Publications Warehouse

Water resources data for the 2003 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 3 contains (1) discharge records for 61 continuous-record streamflow-gaging stations, 5 partialrecord stations and 13 special study and miscellaneous streamflow sites; (2) elevation and contents records for 11 lakes and reservoirs; (3) water-quality records for 8 lakes and reservoirs; (4) water-quality records for 23 gaging stations and 26 ungaged streamsites; (5) water-level records for 23 ground-water network observation wells. Site locations are shown in figures throughout the report. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 1 and 2, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

Siwicki, Raymond W.

2004-01-01

452

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

ERIC Educational Resources Information Center

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…

Great Lakes United, Buffalo, NY.

453

Author's personal copy Fossil brines preserved in the St-Lawrence Lowlands,  

E-print Network

halite disso- lution. 87 Sr/86 Sr ratios and Ca excess indicate prolonged interactions with silicate degassing, are identical to their production ratios in rocks. The source of salinity (halite dissolution during Devonian­Silurian time. Brines might result from infiltration of Devonian water leaching halite

Long, Bernard

454

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

USGS Publications Warehouse

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)

Bugliosi, Edward F.

1987-01-01

455

Shoreline retreat and coastal storms in the southern Gulf of St. Lawrence  

NASA Astrophysics Data System (ADS)

Submerged fluvial channels and estuarine facies seaward of the sandy North Shore of Prince Edward Island (Canada) attest to long-term mean relative sea-level rise >2.5 mm/a driving coastal retreat at mean rates >0.5 m/a over the past six thousand years. The shoreface, nearshore multiple bar complexes, and beaches are sand-limited and sand is transferred landward into multidecadal to century-scale storage in coastal dune and flood-tidal delta sinks. Stringent quality control of tide-gauge records for Charlottetown (PEI) indicates mean relative sea-level rise of 3.2 mm/a since 1911. When differenced from tidal predictions, this record provides a decadal sequence of storm surge occurrence for comparison with wind, wave hindcast, and sea-ice data for the southern Gulf over the past several decades. Soft photogrammetric digital rectification of vertical air photographs (1935, 1958, 1968, 1980/1981, 1990) and ground surveys (1989-2001) show large spatial and temporal variance in coastal recession rates, poorly correlated with the overall storm record, in part because of wave suppression by sea ice. Retreat of low sandstone-till cliffs at <1 m/a shows no statistically significant decadal variance. Other sites with shoreline retreat rates typically between 0.5 and 1.5 m/a show localized acceleration after 1980, reflecting a combination of storm impacts, morphodynamic change and sand loss to adjacent tidal inlets. Individual large storms cause localized rapid erosion, from which recovery depends in part on local sand supply. Some barrier shores with dunes show high longshore and interdecadal variance, and extensive multidecadal healing of former inlet and washover gaps. In some areas, at least, this reflects recovery from an episode of widespread washover predating the 1935 photography.

Forbes, D. L.; Parkes, G.; Manson, G. K.; Ketch, L.; Solomon, S. M.

2001-05-01

456

Planktonic invaders of the St. Lawrence estuarine transition zone: environmental factors controlling  

E-print Network

controlling the distribution of zebra mussel veligers Christine Barnard, Jean-Jacques Frenette, and Warwick F Introduction Zebra mussels, Dreissena polymorpha, have spread throughout North American aquatic ecosystems

Vincent, Warwick F.

457

Family Factors in Migration Plans of Youth, High School Seniors in St. Lawrence County, New York.  

ERIC Educational Resources Information Center

Analyses of data obtained from 790 questionnaires collected from a sample of public high school seniors in a relatively low income, sparsely settled county in northern New York State in May, 1962, revealed some of the effects of 2 family systems--the immediate family and the extended family--on the migration planning of high school seniors.…

Crawford, Charles O.

458

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

PubMed Central

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

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

459

Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes  

USGS Publications Warehouse

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.

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

460

MAIA Estuaries 1997-98 Data  

NSDL National Science Digital Library

The Mid Atlantic Integrated Assessment program (MAIA) of the Environmental Protection Agency (EPA) has released these estuaries data for 1997-98. Data and Metadata may be viewed or downloaded (text or .pdf) for the following variables: Sampling Station Location Data, Station Visit Data, Water Quality Physical Measurements, Water Quality- Nutrients Data, Sediment Grain Size Data, Sediment Toxicity Data, Sediment Chemistry Data, Benthic Community Grain Size Data, Benthic Abundance Data, Benthic Biomass Data, Benthic Community Summary Data, Chemical Analyte Code Table, and Benthic Taxon Code Table.

461

Denitrification in the river estuaries of the northern Baltic Sea.  

PubMed

Estuaries have been suggested to have an important role in reducing the nitrogen load transported to the sea. We measured denitrification rates in six estuaries of the northern Baltic Sea. Four of them were river mouths in the Bothnian Bay (northern Gulf of Bothnia), and two were estuary bays, one in the Archipelago Sea (southern Gulf of Bothnia) and the other in the Gulf of Finland. Denitrification rates in the four river mouths varied between 330 and 905 micromol N m(-2) d(-1). The estuary bays at the Archipelago Sea and the Gulf of Bothnia had denitrification rates from 90 micromol N m(-2) d(-1) to 910 micromol N m(-2) d(-1) and from 230 micromol N m(-2) d(-1) to 320 micromol N m(-2) d(-1), respectively. Denitrification removed 3.6-9.0% of the total nitrogen loading in the river mouths and in the estuary bay in the Gulf of Finland, where the residence times were short. In the estuary bay with a long residence time, in the Archipelago Sea, up to 4.5% of nitrate loading and 19% of nitrogen loading were removed before entering the sea. According to our results, the sediments of the fast-flowing rivers