Food of Double-crested Cormorants,Phalacrocorax auritus, in the Gulf and Estuary of the St. Lawrence River, Quebec, Canada

1998 ◽  
Vol 76 (4) ◽  
pp. 635-643 ◽  
Author(s):  
Jean-François Rail ◽  
Gilles Chapdelaine

Between 1994 and 1996, a total of 613 Double-crested Cormorant (Phalacrocorax auritus) regurgitations were collected at four colonies located in the St. Lawrence Estuary and one colony on the North Shore of the Gulf of St. Lawrence. The diet comprised a great variety of prey, with fishes well represented. Capelin (Mallotus villosus) and sand lance (Ammodytes sp.) together constituted most of the diet, (i.e., frequency of occurrence 66%, numerical frequency 68%, and volume 50%). Sand lance, which were nearly absent in regurgitations from the Estuary, were important in the diet of cormorants from the North Shore of the Gulf. At the North Shore colony, capelin were much more abundant in the diet in 1996 than in 1995, which correlates with independent fisheries data. In contrast to the results of previous studies of this cormorant's diet, our results show a preponderance of schooling fishes over benthic species. We suggest that this reflects a recent trend towards an increase in the abundance of schooling fishes in the St. Lawrence Estuary and Gulf. Overfishing of predatory fishes and oceanographic factors could be involved.

2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.


1983 ◽  
Vol 61 (7) ◽  
pp. 1465-1471 ◽  
Author(s):  
François-Xavier Garneau ◽  
Jean-Luc Simard ◽  
Odette Harvey ◽  
John W. Apsimon ◽  
Michel Girard

The isolation of the major triterpene glycoside from the sea cucumber Psolusfabricii obtained from the north shore of the St. Lawrence estuary is described. Versatile extraction and purification procedures were used and physico-chemical data is presented in support of structure 1 for psoluthurin A.


2010 ◽  
Vol 31 (1-2) ◽  
pp. 61-80 ◽  
Author(s):  
Jean-Claude Dionne

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%.


1987 ◽  
Vol 65 (6) ◽  
pp. 1363-1376 ◽  
Author(s):  
Peggy L. Edds ◽  
J. Andrew F. Macfarlane

Baleen whale movements were monitored from a hillside on the north shore of the St. Lawrence Estuary from 28 June to 27 September 1979. No diurnal or tidal relationships were apparent for the two most abundant species, the minke and finback. Single minke whales were seen almost daily. Adult pairs were only seen on four dates, and no adult-calf pairs were observed. Twenty-two small minkes were observed; three were possibly 1st-year calves. Finbacks occurred singly and in groups, particularly later in the field season. Resightings of distinctive finbacks indicate that adult pairings are temporary. One finback had been seen in the area in 1973–1975. Adult–calf pairs and seven single juveniles were also seen. Observations of finbacks pursued by whale watchers provide evidence that some regulation of the rapidly growing whale-watching industry may be warranted. Blue whales and humpback whales were seen far less frequently than minkes and finbacks. The relative abundances of minke, finback, and humpback were similar to 1973–1974 in the same area: however, blue whales were seen far more frequently in the past.


1994 ◽  
Vol 72 (12) ◽  
pp. 2100-2104 ◽  
Author(s):  
David A. Clugston ◽  
Jerry R. Longcore ◽  
Daniel G. McAuley ◽  
Pierre Dupuis

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 – 26 384 m). Mean home range size was 27.6 ± 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 ± 7.4%) and exhibited high fidelity to a day-use area before the hunting season (73 ± 7.3%).


2002 ◽  
Vol 39 (8) ◽  
pp. 1239-1255 ◽  
Author(s):  
Jean-Claude Dionne

At Rivière-Blanche, a locality on the south shore of the lower St. Lawrence estuary, the clayey and rocky shore zone is largely covered by stones of various sizes and lithologies, from local and far-distant sources. A survey exceeding 31 000 boulders indicates that 31% are Precambrian clasts (granite, gneiss, anorthosite, etc.) from the Canadian Shield located on the north shore of the St. Lawrence, 40 km from Rivière-Blanche, and 69% are Appalachian lithologies, mainly (45%) sandstone and graywacke. There are also 1.5% of dolostone erratics, a lithology not widespread in the Canadian Shield nor in the Appalachians. Of the 1242 clasts of the various varieties of dolostone erratics observed, the grey coral (Cladopora) dolostone erratics are restricted to the Rivière-Blanche area, whereas many other varieties are common to both shores of the St. Lawrence estuary. The most likely far-distance source is the Proterozoic Mistassini sedimentary basin, while a few varieties such as the coral dolostone erratics are from the Appalachian Siluro-Devonian formations, of which the nearest outcrops are located in the northwestern area of Lake Matapedia, 25–30 km south of Rivière-Blanche. Whatever their source, the dolostone erratics were first transported by a late Wisconsinian regional ice stream before being released by icebergs in the Goldthwait Sea. The coral dolostone (Clapodora) erratics provide additional evidence for a northward ice flow between Lake Matapedia and Rivière-Blanche during an early phase of deglaciation of the St. Lawrence Valley after the formation of an Appalachian ice divide located approximately at the latitude of Lac-au-Saumon.


1984 ◽  
Vol 74 (2) ◽  
pp. 595-603
Author(s):  
F. M. Anglin

Abstract Continuous monitoring of the seismically active Charlevoix zone since late 1977 has delineated the boundaries of the earthquake zone under the north shore and has enabled an association to be made with surface mapped faults that strike along the St. Lawrence Valley and dip to the southeast. Within the active zone, aseismic volumes are found under parts of the St. Lawrence River and another elongated zone of activity is found to the southeast on unmapped faults dipping under the river. The previous suggestions that the activity is related to old rift faults, which have been later weakened by a meteor impact, would seem to be upheld.


1969 ◽  
Vol 6 (4) ◽  
pp. 771-774 ◽  
Author(s):  
Douglas S. Rankin ◽  
Ravi Ravindra ◽  
David Zwicker

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.


1983 ◽  
Vol 40 (1) ◽  
pp. 52-60 ◽  
Author(s):  
J. Lebel ◽  
E. Pelletier ◽  
M. Bergeron ◽  
N. Belzile ◽  
G. Marquis

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.


1992 ◽  
Vol 19 (2) ◽  
pp. 252-259 ◽  
Author(s):  
François Anctil ◽  
Jean-Pierre Troude

Data available on water levels in the St. Lawrence Estuary were used to evaluate the relative variation of mean water levels in this area. Only measurements taken at Pointe-au-Père could be used to evaluate this parameter with the required precision; a relative stability of water levels (−0.3 ± 0.5 mm/year) was observed. Upstream stations, especially the ones in the estuary, are highly influenced by the freshwater input of the St. Lawrence River. The high discharge of the river has been identified as the main cause of high water levels observed between 1970 and 1988 and, consequently, of bank erosion at the limit of the St. Lawrence estuary. Key words: discharge, erosion, estuary, mean water level, relative variation.


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