Les parasites de l'éperlan d'amérique (Osmerus mordax) anadrome du Québec et leur utilité comme étiquettes biologiques

1983 ◽  
Vol 61 (3) ◽  
pp. 621-626 ◽  
Author(s):  
A. Fréchet ◽  
J. J. Dodson ◽  
H. Powles
Keyword(s):  
Osmerus Mordax ◽  
The South ◽  
Lawrence Estuary ◽  
Fourth Group ◽  
Saguenay Fjord ◽  
South Shore ◽  
St Lawrence Estuary

Distribution of smelt parasites Glugea hertwigi, Diphyllobothrium sebago, and Echinorhynchus salmonis support previous hypotheses that three groups of anadromous smelt occur in Quebec waters. These groups are associated with three geographical areas: the Saguenay fjord, the south shore of the St. Lawrence estuary, and Chaleur Bay. Furthermore, the presence of two parasites almost exclusive to the smelt sampled in Forestville and Baie Comeau confirms the existence of a fourth group.

Use of Variation in Biological Characters for the Classification of Anadromous Rainbow Smelt (Osmerus mordax) Groups

1983 ◽  
Vol 40 (6) ◽  
pp. 718-727 ◽  
Author(s):  
A. Fréchet ◽  
J. J. Dodson ◽  
H. Powles
Keyword(s):  
Open Water ◽  
Growth Patterns ◽  
Osmerus Mordax ◽  
Rainbow Smelt ◽  
Lawrence Estuary ◽  
Saguenay Fjord ◽  
South Shore ◽  
Lower North Shore ◽  
St Lawrence Estuary

Analysis of meristics, growth patterns, and fecundity to somatic weight relationships of spawning anadromous rainbow smelt (Osmerus mordax) in Quebec waters demonstrated the existence of three geographical groups (Chaleur Bay, south shore of the St. Lawrence Estuary, and Saguenay Fjord). Although homing to spawning rivers does not appear to occur, the degree of heterogeneity of spawning smelt of different geographical areas is less at the extremes of their Quebec distribution. Classification of smelt from the commercial fishery catch indicates limited mixing of these groups during open-water migration. The existence of a fourth group is suggested by classification analysis of smelt caught along the lower north shore of the St. Lawrence Estuary.

scholarly journals La mer de Goldthwait au Québec

2010 ◽  
Vol 31 (1-2) ◽  
pp. 61-80 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Quebec City ◽  
The South ◽  
Lawrence Estuary ◽  
Marine Invasion ◽  
North Shore ◽  
The North ◽  
Upper Limit ◽  
South Shore ◽  
Anticosti Island ◽  
St Lawrence Estuary

The Goldthwait Sea is defined as the late- and post-Glacial marine invasion in the St. Lawrence Estuary and Gulf east of Québec City. In Québec, this sea has submerged an area of about 25 000 km2. The largest areas submerged are the north shore of the St. Lawrence between Les Escoumins and Blanc-Sablon, the south shore between Levis and Tourelles, and the Anticosti Island. The upper limit of the Goldthwait Sea varies from place to place. The Goldthwait Sea began 14 000 years ago and land emergence is still in progress, since the pre-Wisconsin marine level has not been recovered yet. For a better chronology, this long interval needs to be subdivided. Three main periods have been recognized: Goldthwaitian I, II and III. However, a geographical subdivision is also needed. Numerous shorelines were observed at various elevations throughout the area formely submerged by the Goldthwait Sea. However, only a few shorelines are well developed and extensive, and correlations between former shorelines are difficult to establish. Only three levels are widespead and common to the Estuary and parts of the Gulf. The isostatic recovery has been rapid during the first three thousand years after déglaciation of the area: about 75%.

Mud Cracks and Polygons on Ice Push Ridges, in Tidal Flats of the St. Lawrence Estuary

1974 ◽  
Vol 11 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Water Level ◽  
Tidal Flats ◽  
The South ◽  
Lawrence Estuary ◽  
Waves And Currents ◽  
South Shore ◽  
Break Up ◽  
St Lawrence Estuary

Mud cracks and polygons form during summer in tidal flats of the south shore of the St. Lawrence Estuary. They occur near mean low water level at the top surface of ice push mud ridges formed during winter and break-up. They are a source of mud clasts which settle in the surroundings when carried away by waves and currents.

scholarly journals Formes de corrosion littorale, côte sud du Saint-Laurent

2005 ◽  
Vol 11 (23) ◽  
pp. 379-395 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Geographical Distribution ◽  
Rocky Shores ◽  
The South ◽  
Cold Regions ◽  
Lawrence Estuary ◽  
South Shore ◽  
St Lawrence Estuary ◽  
First Time ◽  
Extensive Bibliography

Corrosion features were observed on the South Shore of the Maritime St. Lawrence Estuary, in conglomerate, limestone, sandstone, shale and cristalline boulders, and are here described for the first time. An attempt to classify these minor features characteristic of rocky shores is made and an extensive bibliography is given. An effort should be made to get more information on the geographical distribution of coastal corrosion forms on non calcareous rocks in cold regions.

Holocene Relative Sea-Level Fluctuations in the St. Lawrence Estuary, Québec, Canada

1988 ◽  
Vol 29 (3) ◽  
pp. 233-244 ◽  
Author(s):  
J.C. Dionne
Keyword(s):  
Sea Level ◽  
The South ◽  
Relative Sea Level ◽  
Lawrence Estuary ◽  
Sea Level Fluctuations ◽  
Emergence Curve ◽  
South Shore ◽  
Slight Rise ◽  
St Lawrence Estuary

Between 7000 and 6000 yr B.P., relative sea level was as much as 5 m lower than today in the St. Lawrence estuary, Québec. A small transgression (Laurentian transgression) occurred between 5800 and 4400 yr B.P., which resulted in the construction of an 8- to 10-m terrace. About 3000 yr B.P., relative sea level was similar to present, and then a stillstand or a slight rise occurred during which a cliff (Micmac cliff) was cut into the emerged terrace. During a subsequent lowering of relative sea level (coastal emergence), a low aggradational terrace (Mitis terrace) was built between 2300 and 1500 yr B.P. at the base of the Micmac cliff. A new emergence curve for the south shore of the St. Lawrence estuary showing a mid-Holocene high stand of relative sea level is therefore proposed.

New records of the mysids Boreomysis nobilis G. O. Sars and Mysis litoralis (Banner) in the Saguenay fjord (St. Lawrence estuary)

1974 ◽  
Vol 52 (8) ◽  
pp. 1087-1090 ◽  
Author(s):  
David C. Judkins ◽  
Robert Wright
Keyword(s):  
New Records ◽  
The Arctic ◽  
Glacial Period ◽  
Isolated Populations ◽  
Lawrence Estuary ◽  
Midwater Trawl ◽  
Boreal Region ◽  
Saguenay Fjord ◽  
St Lawrence Estuary

The arctic–subarctic mysids Boreomysis nobilis and Mysis litoralis were abundant in midwater trawl collections from the Saguenay fjord but were almost absent in collections from the confluent St. Lawrence estuary and Gulf of St. Lawrence. Collections from the estuary and Gulf contained boreal mysids more typical of the latitude. The presence of apparently isolated populations of B. nobilis and M. litoralis in the fjord is further evidence that it is an arctic enclave within a boreal region. The hypothesis that populations of arctic and subarctic species in the Saguenay fjord are relicts from a previous glacial period is questioned in view of the possibility of more recent faunal exchange between the Arctic and the fjord via intermediate arctic enclaves on the eastern Canadian coast.

scholarly journals Spatial variations in CO<sub>2</sub> fluxes in the Saguenay Fjord (Quebec, Canada) and results of a water mixing model

2020 ◽  
Vol 17 (2) ◽  
pp. 547-566 ◽  
Author(s):  
Louise Delaigue ◽  
Helmuth Thomas ◽  
Alfonso Mucci
Keyword(s):  
Surface Waters ◽  
Brackish Water ◽  
Field Measurements ◽  
Mixing Model ◽  
Isotopic Tracers ◽  
Lawrence Estuary ◽  
Relative Contribution ◽  
Saguenay Fjord ◽  
Spring Freshet ◽  
St Lawrence Estuary

Abstract. The Saguenay Fjord is a major tributary of the St. Lawrence Estuary and is strongly stratified. A 6–8 m wedge of brackish water typically overlies up to 270 m of seawater. Relative to the St. Lawrence River, the surface waters of the Saguenay Fjord are less alkaline and host higher dissolved organic carbon (DOC) concentrations. In view of the latter, surface waters of the fjord are expected to be a net source of CO2 to the atmosphere, as they partly originate from the flushing of organic-rich soil porewaters. Nonetheless, the CO2 dynamics in the fjord are modulated with the rising tide by the intrusion, at the surface, of brackish water from the Upper St. Lawrence Estuary, as well as an overflow of mixed seawater over the shallow sill from the Lower St. Lawrence Estuary. Using geochemical and isotopic tracers, in combination with an optimization multiparameter algorithm (OMP), we determined the relative contribution of known source waters to the water column in the Saguenay Fjord, including waters that originate from the Lower St. Lawrence Estuary and replenish the fjord's deep basins. These results, when included in a conservative mixing model and compared to field measurements, serve to identify the dominant factors, other than physical mixing, such as biological activity (photosynthesis, respiration) and gas exchange at the air–water interface, that impact the water properties (e.g., pH, pCO2) of the fjord. Results indicate that the fjord's surface waters are a net source of CO2 to the atmosphere during periods of high freshwater discharge (e.g., spring freshet), whereas they serve as a net sink of atmospheric CO2 when their practical salinity exceeds ∼5–10.

Le Panache du Saguenay

1983 ◽  
Vol 40 (1) ◽  
pp. 52-60 ◽  
Author(s):  
J. Lebel ◽  
E. Pelletier ◽  
M. Bergeron ◽  
N. Belzile ◽  
G. Marquis
Keyword(s):  
Surface Layer ◽  
Deep Water ◽  
High Tide ◽  
Lawrence Estuary ◽  
Fresh Waters ◽  
Saguenay Fjord ◽  
Region Data ◽  
Saguenay River ◽  
St Lawrence Estuary ◽  
St Lawrence River

The large difference between the alkalinity of the fresh waters of the St. Lawrence River (1.475 mmol∙kg−1) and the Saguenay River (0.134 mmol∙kg−1) was used to locate the region on the St. Lawrence estuary which is under the influence of the Saguenay River. This method has the advantage over classical measurements such as salinity and temperature that it is independent of the upwelling of deep water in this region. Data was obtained in the St. Lawrence estuary near the mouth of the Saguenay fjord using a network of 33 stations at slack low tide and 23 stations at slack high tide. The results show that, at low tide, Saguenay water forms a plume which extends more than 10 km from the mouth of the fjord into the estuary. At high tide the plume is restricted to the surface layer as the Saguenay waters are pushed back into the fjord.

Distribution des spectres de taille des particules en suspension dans le fjord du Saguenay

1979 ◽  
Vol 16 (2) ◽  
pp. 240-249 ◽  
Author(s):  
J. P. Chanut ◽  
S. A. Poulet
Keyword(s):  
Particle Size ◽  
Water Mass ◽  
Layer Structure ◽  
Principal Component ◽  
Water Masses ◽  
Size Spectra ◽  
Lawrence Estuary ◽  
Saguenay Fjord ◽  
Bottom Waters ◽  
St Lawrence Estuary

The spatial distribution of particle size spectra shows a two-layer stratification in May but reveals three-layer structure in September, both in the Saguenay fjord and in the adjacent waters of the St. Lawrence estuary, near the sill. In May, the particle size spectra in the surface layer show considerable variability whereas, in the bottom waters, they appear to be relatively homogeneous. In September, the deeper, more homogeneous water mass is less extensive. It is apparently eroded by diffusion and advection during summer months and becomes restricted to intermediate depths towards the head of the fjord. During the same period, a water mass with physical and particulate properties different from the upper layers occupies the bottom of the fjord. Principal component analysis shows that variations in particle size spectra are independent from one layer to another. Water masses with identical physical and particulate properties located in both sides of the sill illustrate the influence of the St. Lawrence estuary on the Saguenay fjord. These water masses, generally located below the sill depth, indicate the existence of powerful advective mechanisms in this region.

Régime alimentaire et principaux facteurs influençant l'alimentation des larves de capelan (Mallotus villosus), d'éperlan (Osmerus mordax) et de hareng (Clupea harengus harengus) dans un estuaire partiellement mélangé

1986 ◽  
Vol 43 (5) ◽  
pp. 968-979 ◽  
Author(s):  
R. Courtois ◽  
J. J. Dodson
Keyword(s):  
Feeding Rate ◽  
Water Masses ◽  
Clupea Harengus ◽  
Gut Contents ◽  
Osmerus Mordax ◽  
Lawrence Estuary ◽  
Daily Cycles ◽  
Food And Feeding ◽  
Clupea Harengus Harengus ◽  
St Lawrence Estuary

The food and feeding rate periodicity of larvae of capelin (Mallotus villiosus), smelt (Osmerus mordax), and herring (Clupea harengus harengus) were studied to determine the existence of potential interactions between the larvae of these three species. Analyses of the gut contents showed that larvae of capelin started to feed before yolk sac absorption but that the feeding rate was low (<20%) in the lower St. Lawrence estuary; the small size of capelin larvae restricted their feeding to tintinnids. Larvae of the two other species feed at a greater rate than capelin larvae and their food is more diverse. The temporal sequence of feeding incidences showed daily cycles for the three species and semidiurnal cycles for larvae of capelin and herring. The importance of light for feeding of larvae was confirmed by the daily cycles and by the greater abundance of larvae with gut contents in surface waters (0–20 m). From the absence of a relation between biotic factors (density of larvae) and the temporal evolution of feeding incidences, we suggest that semidiurnal cycles are mainly related to temperature changes associated with advection of water masses at the sampling stations. Even though similar reactions to certain environmental variables were observed, we concluded that interspecific competition is minimal between larvae of the three species. Although present at the same stations, larvae of different species mainly occurred in distinct water masses; they are also mainly of different size. Those characteristics force them to exploit organisms of different size and mainly of different species.

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