The structure and composition of epilithic diatom communities of the St. Lawrence and Ottawa rivers in the Montreal area

1981 ◽  
Vol 59 (3) ◽  
pp. 377-387 ◽  
Author(s):  
Michèle A. de Seve ◽  
Melvin E. Goldstein
Keyword(s):  
Species Richness ◽  
Information Measure ◽  
The South ◽  
Ottawa River ◽  
Diatom Communities ◽  
Upstream Station ◽  
South Shore ◽  
Lower Biomass ◽  
Epilithic Diatom ◽  
St Lawrence River

The structure and composition of epilithic diatom communities were studied at five stations in the St. Lawrence River and one station in the Ottawa River, adjacent to the south shore of the island of Montreal. The diatom flora was composed of 139 species and varieties of Bacillariophyceae. The species composition generally reflected a eutrophic and organically polluted environment. The structure of the diatom communities of the Ottawa River (station I) and of the St. Lawrence River upstream (station II) and downstream along the south shore of the island of Montreal (stations III and IV) was similar with respect to total number of species (41–44 species), diversity (species richness (d): 3.01–3.88 and Shannon-Weiner information measure of diversity [Formula: see text]: 2.01–3.34), and biomass (463.9–1656.0 μm3/mm2). Further downstream station V had fewer species (12 species) and a significantly (P < 0.05) lower diversity (species richness d: 1.87 and Shannon-Weiner information measure of diversity [Formula: see text]: 0.35). The station below it (station VI) had a significantly (P < 0.05) lower biomass (51.2 μm3/mm2) and a lower density (68 cells/mm2). The structure and composition of the diatom communities at the different stations are discussed in relation to environmental factors.

Preliminary interpretation of the first refraction arrivals in Gaspé from shots in Labrador and Quebec

1969 ◽  
Vol 6 (4) ◽  
pp. 771-774 ◽  
Author(s):  
Douglas S. Rankin ◽  
Ravi Ravindra ◽  
David Zwicker
Keyword(s):  
Upper Mantle ◽  
Arrival Time ◽  
The South ◽  
North Shore ◽  
The North ◽  
A Value ◽  
South Shore ◽  
Compressional Velocity ◽  
St Lawrence River

Previous work in the Gulf of St. Lawrence has yielded an unusually high upper-mantle compressional velocity. In the Gaspé area a more recent determination has yielded a value of 8.75 ± 0.20 km/s for an unreversed profile. The arrival time at a station on the north shore of the St. Lawrence River suggests that there is no major difference in velocity and depth relative to the south shore.

scholarly journals An Explanation of Port Activity on the South Shore of the Lower St.Lawrence Rive

2005 ◽  
Vol 17 (40) ◽  
pp. 135-154
Author(s):  
B. Slack
Keyword(s):  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Size Variation ◽  
Quebec City ◽  
The South ◽  
Port System ◽  
South Shore ◽  
St Lawrence River

The study examines the factors that affect variations in port size in the region below Québec City on the south shore of the St. Lawrence River. The investigation draws upon the results of earlier studies and measures the relationships between six factors and port size. Multiple regression analysis produces a model that accounts for over 90 per cent of size variation in the port System.

Phytoplankton assemblages in the St. Lawrence River, downstream of its confluence with the Ottawa River, Quebec, Canada

2000 ◽  
Vol 57 (S1) ◽  
pp. 16-30 ◽  
Author(s):  
Christiane Hudon
Keyword(s):  
Great Lakes ◽  
Water Clarity ◽  
Phytoplankton Assemblages ◽  
River Waters ◽  
Taxa Richness ◽  
Ottawa River ◽  
Water Characteristics ◽  
Biological Impacts ◽  
Lower Biomass ◽  
St Lawrence River

Consistent differences in physical, chemical, and biological characteristics were observed along a transversal river section located 2 km downstream of the confluence of the Ottawa and the St. Lawrence rivers. Phytoplankton sampled at stations subject to the influence of the St. Lawrence River had a lower biomass, smaller cell volume, lower chlorophyll a, and lower taxa richness than did phytoplankton at stations influenced by the Ottawa River. The stations influenced by St. Lawrence River waters showed regular seasonal changes in phytoplankton biomass and composition, reflecting the major impact of the stratification and mixing cycles observed in the Great Lakes. By comparison, at the stations influenced by Ottawa River waters, monthly variations were found in biomass and composition correlated with temperature and water clarity, suggesting the effects of the watershed's morphology. A discharge reduction of 12% in the St. Lawrence River and 46% in the Ottawa River between summer 1994 and summer 1995 coincided, for stations in both water masses, with lower biomass and greater species richness and an increase in taxa that generate noxious smells and odours. Phytoplankton is recommended for use in monitoring the biological impacts of changes in water characteristics resulting from human activities and climate change in the Great Lakes watershed.

Lateral variations in upper crustal structure below the La Malbaie area from slowness, azimuth, and traveltime measurements of telleseisms

1977 ◽  
Vol 14 (10) ◽  
pp. 2284-2293 ◽  
Author(s):  
D. J. Hearty ◽  
R. F. Mereu ◽  
C. Wright
Keyword(s):  
Precambrian Basement ◽  
Precambrian Rock ◽  
The South ◽  
Local Seismicity ◽  
North Shore ◽  
The North ◽  
South Shore ◽  
Lateral Variations ◽  
Teleseismic Events ◽  
St Lawrence River

A temporary seismic network located in the La Malbaie region of eastern Quebec during the summer of 1974 for studying the local seismicity of the area was used as a seismic array to measure directly the slowness and azimuth of the P arrivals from 18 teleseismic events. A consistent bias in the arrival vectors was observed for rays approaching the array from the south (i.e. azimuths 181°–227°). This bias can be explained by a thickening of sedimentary strata beneath the south shore of the St. Lawrence River as opposed to the outcropping Precambrian basement rock on the north shore. The sedimentary accumulation can be interpreted in terms of a sloping interface located under the network between sediments and Precambrian rock or a thick horizontal sedimentary layer underlying the south shore of the St. Lawrence River.

Loadings of Selected Chemicals into the St. Lawrence River System from Lake Ontario, 1986/87

1989 ◽  
Vol 24 (4) ◽  
pp. 589-608 ◽  
Author(s):  
I.K. Tsanis ◽  
J. Biberhofer ◽  
C.R. Murthy ◽  
A. Sylvestre
Keyword(s):  
Mass Balance ◽  
Lake Ontario ◽  
River System ◽  
Vertical Gradient ◽  
The South ◽  
Measured Concentration ◽  
Chemical Monitoring ◽  
The North ◽  
Loading Estimates ◽  
St Lawrence River

Abstract Determination of the mass output through the St. Lawrence River outflow system is an important component in computing mass balance of chemical loadings to Lake Ontario. The total flow rate in the St. Lawrence River System at the Wolfe Island area was calculated from detailed time series current meter measurements from a network of current meters and Lagrangian drifter experiments. This flow is roughly distributed in the ratio of 55% to 45% in the South and North channel, respectively. Loading estimates of selected chemicals have been made by combining the above transport calculations with the ongoing chemical monitoring data at the St. Lawrence outflow. A vertical gradient in the concentration of some organic and inorganic chemicals was observed. The measured concentration for some of the chemicals was higher during the summer months and also is higher in the South Channel than in the North Channel of the St. Lawrence River. These loading estimates are useful not only for modelling the mass balance of chemicals in Lake Ontario but also for serving as input loadings to the St. Lawrence River system from Lake Ontario.

WATER QUALITY MONITORING IN THE SOUTH SHORE ESTUARIES OF LONG ISLAND, NEW YORK

2018 ◽  
Author(s):  
Rebeka Smith ◽  
◽  
Thomas Badamo ◽  
David J. Barclay ◽  
Devorah Crupar ◽  
...  
Keyword(s):  
Water Quality ◽  
New York ◽  
Long Island ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
The South ◽  
South Shore

CARACTÉRISTIQUES DES SOLS SULFATÉS ACIDES DE LA SÉRIE DE L'ANSE EN MILIEU ESTUARIEN (QUÉBEC)

1988 ◽  
Vol 68 (3) ◽  
pp. 577-592
Author(s):  
C. R. DE KIMPE ◽  
M. R. LAVERDIERE ◽  
R. W. BARIL
Keyword(s):  
Key Words ◽  
Lower Limit ◽  
Marine Sediments ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
Organic C ◽  
South Shore ◽  
Sulfate Soils ◽  
Sulfate Leaching ◽  
St Lawrence River

Acid sulfate soils were sampled according to the transect method in four bays along the south shore of the St. Lawrence river to determine their properties in their area of distribution. In each bay, six profiles of cultivated soils were sampled along a transect perpendicular to the river. One non-cultivated profile was also sampled at l'Isle-Verte. The lower limit of the B horizons, between 79 and 89 cm, suggested a homogeneous development of these soils across the area. Most profiles contained jarosite in the lower Bg and, sometimes, in the C horizons; this mineral was absent in the upper part of the profiles of soils that had been limed prior to cultivation. Total S content increased with depth, but only a few horizons had a content > 0.75% presumably because of sulfate leaching once the soils were drained. Organic C content in the de l'Anse soils decreased less rapidly with depth than in other gleysolic soils, because vegetation grew while sediments were being deposited. Key words: Acid sulfate soils, total S, recent marine sediments, jarosite

Estimation de la production de jeunes plantations de pin rouge et de pin gris du sud du Québec

1976 ◽  
Vol 6 (4) ◽  
pp. 478-486 ◽  
Author(s):  
H. A. Bolghari
Keyword(s):  
Multiple Regression ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Plantations ◽  
Regression Equations ◽  
Pine Plantation ◽  
South Shore ◽  
Pine Stands ◽  
Natural Stands ◽  
St Lawrence River

Multiple regression equations have been developed to predict yield from young red pine and jack pine plantations. Data from 446 sample plots representing young red pine and jack pine stands located on the south shore of the St. Lawrence River between Quebec and Montreal were analysed. The red pine plantation yielded more than the jack pine. However, in plantation both species yield more than in natural stands. Taking into account the age and spacing of the sampled plantations, the equation obtained can provide information on yield of red pine and jack pine stands the maximum spacing of which is 3 × 3 m, up to the age of 45 and 35 years respectively. The equations will allow the construction of preliminary yield tables for both species.

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