The estuary of the Saint Lawrence in
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
, Canada, is one of the largest
esturaries in the world.
Situation
The
estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...
of the
St. Lawrence River
The St. Lawrence River (french: Fleuve Saint-Laurent, ) is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a (roughly) northeasterly direction, into the Gulf of St. Lawrence, connecting ...
is located downstream of the St. Lawrence River and upstream of the
Gulf of St. Lawrence. It refers to the place where the fresh and salt waters mix between the river and the gulf. The St. Lawrence Estuary begins at
Lake Saint-Pierre and ends at the widening of the shores, at the height of
Pointe-des-Monts, Quebec, opposite
Les Méchins, Quebec. It is divided into three sections: the St. Lawrence River estuary at
Île d'Orléans
Île d'Orléans (; en, Island of Orleans) is an island located in the Saint Lawrence River about east of downtown Quebec City, Quebec, Canada. It was one of the first parts of the province to be colonized by the French, and a large percentage ...
(Orleans Island), the middle estuary to the
Saguenay Fjord
Saguenay Fjord National Park (french: parc national du Fjord-du-Saguenay) is a provincial park located in Quebec, Canada. In the regions of Saguenay–Lac-Saint-Jean, Charlevoix, Côte-Nord, and Bas-Saint-Laurent, the park is situated along the ...
, the maritime estuary to Pointe-des-Monts, Quebec.
The St. Lawrence Estuary is characterized by a saline front at the eastern tip of Île d'Orléans. The zone of contact between fresh and salt water corresponds to a region of high concentrations of suspended matter causing a zone of maximum turbidity (MTZ) of a length that can vary from , depending on the flow of the river. This zone of maximum turbidity is located between Île d'Orléans (salinity greater than 0
PSU) and Île aux Coudres (salinity below 10 PSU). The mechanisms of estuarine circulation associated with this environment make it a privileged site of primary and secondary production which shelters many fish nurseries. High environmental turbidity provides shelter against predators while larvae are maintained under optimum temperature and salinity conditions. Large variations in salinity and turbidity result in a wide variety of physicochemical conditions and planktonic communities on the river.
Fauna and flora
An emblematic species is the beluga (beluga whale), but many other species are present. A census of estuary fish was completed in 2008.
[C. Nozères, D. Archambault, P.-M.Chouinard, J. Gauthier, R. Miller, E. Parent, P. Schwab, L. Savard and J.-D. Dutil, ]
Guide to the Identification of Marine Fish in the Estuary and Northern Gulf of St. Lawrence and Protocols for Their sampling during trawl surveys between 2004 and 2008
', Regional Directorate of Science; Fisheries and Oceans Canada, Heavy Document (over 86 Mb)
See also
*
*
Notes
{{DEFAULTSORT:Saint-Laurent, estuary of
Estuaries of Canada
Estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...