Ecology of Benthic Epifauna of the Estuary and Gulf of St. Lawrence: Factors Influencing Their Distribution and Abundance on Buoys

1980 ◽  
Vol 37 (6) ◽  
pp. 979-999 ◽  
Author(s):  
Pierre Fradette ◽  
Edwin Bourget
Keyword(s):  
Water Temperature ◽  
Mytilus Edulis ◽  
Abundant Species ◽  
Freshwater Species ◽  
Lower Estuary ◽  
Lawrence Estuary ◽  
North Shore ◽  
Hiatella Arctica ◽  
The North ◽  
Saguenay Fjord

The invertebrate fauna on 200 buoys moored in the Estuary and Gulf of St. Lawrence was sampled from May through December from 1975 to 1976. A total of 45 species (13 sessile, 32 motile) was collected. The distribution of the most abundant sessile species (Obelia longissima, Mytilus edulis, Hiatella arctica, Balanus crenatus, and Balanus balanoides) was studied in detail. Numbers of organisms and biomass decreased markedly on passing from the Gulf of St. Lawrence to the Lower Estuary and from the Lower Estuary to the Upper Estuary. Numbers of species showed stepwise diminution along with a stepwise increase in turbidity, while community densities decreased progressively with salinities. No sessile species and four motile species were observed in the riverine portion of the Estuary. In the upper portion of the Estuary, freshwater species were found along the south shore whereas euryhaline species were observed on the north shore. Water outflow from the Saguenay Fjord coincided with the limit of penetration or with discontinuities in the distribution of all sessile species within the Estuary. In the Upper Estuary, patches of M. edulis, B. crenatus, and the hydroids O. longissima and Clytia sp. were observed in regions of upwelling. Similarly, in the Gulf, O. longissima was very abundant on buoys near Mingan Islands where there is also an upwelling. The relatively high abundance of hydroids where conditions were generally unfavorable for settlement of sessile organisms was due to their capacity to colonize substrata from the budding of a few individuals. Mytilus edulis was the most abundant species elsewhere in the Gulf, except along the Lower North Shore. Low water temperature influencing larval development of M. edulis in this region best explains low community densities. Variations of growth indices (maximum lengths and mean weights per individual) for M. edulis were related to water temperature and to relative abundance of suspended organic matter in seawater.Key words: benthic epifauna, St. Lawrence Estuary, Gulf of St. Lawrence, ecological distribution, biomass, population density, Mytilus edulis, Balanus crenatus, B. balanoides, Hiatella arctica, Obelia longissima, buoys

Occurrence and general behavior of balaenopterid cetaceans summering in the St. Lawrence Estuary, Canada

1987 ◽  
Vol 65 (6) ◽  
pp. 1363-1376 ◽  
Author(s):  
Peggy L. Edds ◽  
J. Andrew F. Macfarlane
Keyword(s):  
Abundant Species ◽  
Humpback Whales ◽  
Lawrence Estuary ◽  
The Past ◽  
North Shore ◽  
The North ◽  
Minke Whales ◽  
Field Season ◽  
St Lawrence Estuary ◽  
Blue Whales

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.

scholarly journals Do Barrow's Goldeneyes, Bucephala islandica, Breed South of the St. Lawrence Estuary in the Gaspé Peninsula, Eastern Canada?

2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin
Keyword(s):  
North America ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Eastern North America ◽  
Eastern Canada ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Bucephala Islandica ◽  
St Lawrence Estuary

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.

The structure of psoluthurin A, the major triterpene glycoside of the sea cucumber Psolusfabricii

1983 ◽  
Vol 61 (7) ◽  
pp. 1465-1471 ◽  
Author(s):  
François-Xavier Garneau ◽  
Jean-Luc Simard ◽  
Odette Harvey ◽  
John W. Apsimon ◽  
Michel Girard
Keyword(s):  
Triterpene Glycoside ◽  
Sea Cucumber ◽  
Chemical Data ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Extraction And Purification ◽  
Physico Chemical ◽  
St Lawrence Estuary

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.

scholarly journals Fish community composition, seasonality and abundance in Fortaleza Lagoon, cidreira

2004 ◽  
Vol 47 (5) ◽  
pp. 755-763 ◽  
Author(s):  
Lúcia Cabral Schifino ◽  
Clarice Bernhardt Fialho ◽  
José Roberto Verani
Keyword(s):  
Community Composition ◽  
Fish Community ◽  
Abundant Species ◽  
Freshwater Species ◽  
The North ◽  
Fish Community Composition

The Fortaleza Lagoon belongs to the Southern Tramandaí subsystem, formed by lagoons disposed linearly on the north-south direction (30º 08’S, 50º 13’W). The objective of this study was to describe some aspects related to the composition of the fish community of Fortaleza Lagoon. Samples were collected monthly from November 1998 to October 1999. The specimens were captured at four previously determined points in the lagoon, and classified in five orders, 12 families and 22 species. Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus and Loricariichthys anus were more abundant species. Amongst the sampled species only two could not be characterised as freshwater species: Centropomus sp (marine) and Lycengraulius grossidens (estuarine). The ichthyofauna of the lagoon was predominantly composed by constant species.

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%.

scholarly journals Optical properties of size fractions of suspended particulate matter in littoral waters of Québec

2017 ◽  
Vol 14 (23) ◽  
pp. 5297-5312 ◽  
Author(s):  
Gholamreza Mohammadpour ◽  
Jean-Pierre Gagné ◽  
Pierre Larouche ◽  
Martin A. Montes-Hugo
Keyword(s):  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
Total Mass ◽  
Lower Estuary ◽  
Lawrence Estuary ◽  
Specific Absorption ◽  
Size Fractions ◽  
Saguenay Fjord ◽  
Suspended Particulate ◽  
Fraction I

Abstract. Mass-specific absorption (ai∗(λ)) and scattering (bi∗(λ)) coefficients were derived for four size fractions (i =  0.2–0.4, 0.4–0.7, 0.7–10, and > 10 µm, λ = wavelength in nm) of suspended particulate matter (SPM) and with samples obtained from surface waters (i.e., 0–2 m depth) of the Saint Lawrence Estuary and Saguenay Fjord (SLE-SF) during June of 2013. For the visible–near-infrared spectral range (i.e., λ = 400–710 nm), mass-specific absorption coefficients of total SPM (i.e., particulates > 0.2 µm) (hereafter aSPM∗) had low values (e.g., < 0.01 m2 g−1 at λ = 440 nm) in areas of the lower estuary dominated by particle assemblages with relatively large mean grain size and high particulate organic carbon and chlorophyll a per unit of mass of SPM. Conversely, largest aSPM∗ values (i.e., > 0.05 m2 g−1 at λ = 440 nm) corresponded with locations of the upper estuary and SF where particulates were mineral-rich and/or their mean diameter was relatively small. The variability of two optical proxies (the spectral slope of particulate beam attenuation coefficient and the mass-specific particulate absorption coefficient, hereafter γ and Svis, respectively) with respect to changes in particle size distribution (PSD) and chemical composition was also examined. The slope of the PSD was correlated with bi∗(550) (Spearman rank correlation coefficient ρs up to 0.37) and ai∗(440) estimates (ρs up to 0.32) in a comparable way. Conversely, the contribution of particulate inorganic matter to total mass of SPM (FSPMPIM) had a stronger correlation with ai∗ coefficients at a wavelength of 440 nm (ρs up to 0.50). The magnitude of γ was positively related to FSPMi or the contribution of size fraction i to the total mass of SPM (ρs up to 0.53 for i = 0.2–0.4 µm). Also, the relation between γ and FSPMPIM variability was secondary (ρs = −0.34, P > 0.05). Lastly, the magnitude of Svis was inversely correlated with aSPM∗(440) (ρs = −0.55, P = 0.04) and FSPMPIM (ρs = −0.62, P = 0.018) in sampling locations with a larger marine influence (i.e., lower estuary).

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

2004 ◽  
Vol 112 (8) ◽  
pp. 883-888 ◽  
Author(s):  
Fabien Gagnon ◽  
Thierry Tremblay ◽  
Justine Rouette ◽  
Jacques-François Cartier
Keyword(s):  
Lower Estuary ◽  
North Shore ◽  
The North

Terrigenous Organic Matter in Sediments of the St. Lawrence Estuary and the Saguenay Fjord

1979 ◽  
Vol 36 (10) ◽  
pp. 1250-1255 ◽  
Author(s):  
R. Pocklington ◽  
J. D. Leonard
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Substantial Contribution ◽  
Lower Estuary ◽  
Lawrence Estuary ◽  
Carbon To Nitrogen Ratio ◽  
Terrigenous Organic Matter ◽  
Saguenay Fjord ◽  
Nitrogen Ratio ◽  
St Lawrence Estuary

The proportion of land-derived organic matter in sediments of the upper St. Lawrence Estuary is unexpectedly low. In the Saguenay Fjord and the lower estuary, high organic carbon to nitrogen ratios and the presence of lignin indicate a substantial contribution of organic matter from terrestrial sources. The proportion of terrigenous organic matter decreases rapidly thereafter, approaching levels typical of marine sediments in the open Gulf. Key words: Organic matter, sediments, carbon to nitrogen ratio, lignin, St. Lawrence Estuary, Saguenay Fjord

The seals of the Forth, Scotland

1987 ◽  
Vol 93 (3-4) ◽  
pp. 535-543
Author(s):  
J. Harwood ◽  
O. Geraldine Wyile
Keyword(s):  
Abundant Species ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
North Shore ◽  
The North ◽  
Current Trends ◽  
If Current ◽  
Firth Of Forth ◽  
Habitat Damage

SynopsisAlthough common seals (Phoca vitulina L.) do occur in the Firth of Forth, the grey seal (Halichoerus grypus Fab.) is by far the most abundant species in the area. Some pups are born along the north shore of the outer firth but the vast majority are born on the Isle of May. This colony has increased in size from less than twenty-five pups in 1975 to more than 900 in 1986. Studies using conventional and radio tags indicate that many of the seals at the Isle of May originally came from the colony at the Farne Islands, off the Northumberland coast. Information from the Fame Islands population is used to predict future changes at the Isle of May. If current trends continue, more than 2000 pups could be born each year by the end of the century. However, it seems unlikely that this will occur. Management methods for controlling habitat damage are discussed.

Quaternary sedimentation and marine placers along the North Shore, Gulf of St. Lawrence

1993 ◽  
Vol 30 (3) ◽  
pp. 553-574 ◽  
Author(s):  
Frances J. Hein ◽  
James P. M. Syvitski ◽  
Lynda A. Dredge ◽  
Bernard F. Long
Keyword(s):  
Current System ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Mineral Concentration ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Late Wisconsinan ◽  
Mineral Concentrations

Offshore areas, along the North Shore of the St. Lawrence Estuary, have major lithostratigraphic and seismostratigraphic units that relate to the advance or retreat of the Late Wisconsinan Ice Sheet, subsequent marine transgression or regression, and reworking of postglacial deposits. Glacial diamicton and glaciomarine units (acoustic units 1 and 2) were emplaced between >18 and 14.5 ka, by basal meltout or ice-marginal sedimentation; they reflect ice-proximal sedimentation associated with ice-terminal stillstands. Deep-water muds (acoustic unit 3) represent ice-distal accumulation of glaciomarine sediment from glaciofluvial plumes between 13.5 and 11 ka. After this time exceptionally thick nearshore coarse-grained deltaic and estuarine successions (acoustic unit 4) were deposited. The uppermost postglacial sediment (acoustic unit 5) forms the seabed and reflects a reworking phase concomitant with a lowering sea level and ablating Late Wisconsinan ice sheets.Glacioisostatic rebound, which occurred about 23 ka to the present, uplifted glacial and marine deposits and resulted in extensive reworking and production of modern placers. Heavy-mineral concentrations vary as follows: terrestrial tills, 9–20%; modem storm-berm and delta top deposits, 43–60%; delta slope deposits, 25–55%; and deep (170+ m) offshore sediments, 0–2%. Three stages occurred in marine placer formation: (1) 6700 BP, fluvial discharge was high, and fluvial-dominated deltas were built; marine limit was 30 m asl, with progradation of deltas and delivery of sediments with at most 2% heavy minerals; (2) 5200 BP, fluvial discharge was reduced; marine limit was 15 m asl, deltaic sediments were reworked, increasing heavy mineral concentration to 2–8%; (3) 2800 BP, fluvial input was greatly reduced, waves and tides were more influential, a strong littoral current system developed, causing significant reworking of nearshore sediments, heavy mineral concentrations increased, with values exceeding 20% locally. Mass budget calculations show that the second-cycle reworked sediment (acoustic unit 5) is a potential economic target (1 km3, or 1700 Mt). If 7% (using atomic weights) of this target sediment is ilmenite (FeTiO3). then 27 Mt of titanium may be available.

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