Distribution and partition of cobalt, nickel, chromium, and vanadium in the sediments of the Saguenay fjord

1976 ◽  
Vol 13 (12) ◽  
pp. 1706-1718 ◽  
Author(s):  
D. H. Loring

In the Saguenay fjord sediments, cobalt (Co) concentrations vary between 5 and 20 ppm, nickel (Ni) concentrations between 7 and 36 ppm, chromium (Cr) concentrations from 33 to 70 ppm, and vanadium (V) concentrations from 67 to 149 ppm in relation to texture and location. The highest concentrations are found in the fine-grained sediments from the upper part of the fjord and the lowest concentrations occur in the sandy sediments near the mouth of the fjord. On the average, the fjord's muds are neither greatly enriched nor depleted in Co, Ni, Cr, and V when compared to muds from the St. Lawrence estuary and the open Gulf of St. Lawrence.Acetic acid extractions indicate that 8 to 25% of the total Co, 11 to 29% of the total Ni, 2 to 9% of the total Cr, and 5 to 23% of the total V are contributed by the non-detrital fraction and may be available to the biota in the fjord. Non-detrital Co, Ni, Cr, and V appear to have been removed from solution by adsorption onto fine-grained inorganic particles and their distribution controlled by the sedimentation pattern. Non-delrital Cr, V, and Ni are also associated with Mn and Fe oxides, which are present as grain coatings. Most of the Co, Ni, Cr, and V in the detrital fraction, which accounts for 71 to 98% of the total elemental concentrations are found in sulphide, oxide, and ferromagnesian minerals. These minerals accumulate at the same rate as other detrital sedimentary material in response to the present depositional conditions.The discharge of industrial waste has not resulted in an increase in the concentrations of Co, Ni, Cr, and V in the sediments above their natural levels.

1975 ◽  
Vol 12 (7) ◽  
pp. 1219-1237 ◽  
Author(s):  
D. H. Loring

In sediments collected from the Saguenay fjord, the St. Lawrence estuary, and open Gulf of St. Lawrence, total mercury varies with sediment texture and location from 10 to 12 300 ppb (average 386 ppb). The highest concentrations occur in the Saguenay fjord (average 2980 ppb) and the lowest in the open Gulf of St. Lawrence (average 150 ppb). The concentration of mercury increases with decreasing grain size, the highest concentrations occur in the fine-grained sediments of the submarine troughs and shelf valleys and the lowest in the sandy shelf sediments. Analyses of the sediments from the Saguenay fjord, where mercury values range from 12 300 ppb at its head to > 500 ppb in the lower reaches, indicate that most of the mercury (70 to 90% of the total) is held by the organic matter in the sediments. The distribution of mercury in the fjord is apparently controlled by the downstream dispersal from local industrial sources of mercury-rich organic matter, most likely of terrestrial origin because of its high C/N ratio. In the St. Lawrence estuary where mercury values range from 30 to 950 ppb, and in the open Gulf where correlations between variables are lower and scattered anomalies exist, analyses indicate that mercury accumulates along with the fine-grained inorganic and organic matter in response to the present depositional processes. The distribution of mercury appears to be controlled by the sedimentation pattern. Terrestrial organic matter and industrial waste originating in the Saguenay drainage area have the strongest influence on its distribution.


1976 ◽  
Vol 13 (7) ◽  
pp. 960-971 ◽  
Author(s):  
D. H. Loring

Zinc (Zn) concentrations vary between 43 and 145 ppm, copper (Cu) concentrations between 6 and 33 ppm, and lead (Pb) concentrations between 14 and 66 ppm in relation to sediment texture and location in the Saguenay fjord. The concentrations of the elements increase with decreasing grain size; the highest concentrations occur in the fine grained sediments (muds) in the upper part of the fjord and they decrease downstream. On the average, the fjord muds are enriched in Zn and Pb when compared to sediments from the St. Lawrence estuary and the open Gulf of St. Lawrence.Acetic acid extractions of the sediments indicate that 14 to 29% of the total Zn, 14 to 21% of the total Cu, and 12 to 25% of the total Pb is contributed by the non-detrital (acid soluble) fraction, and the remainder (70–88%) is contributed by the detrital (acid insoluble) fraction. Most of the Zn, Cu, and Pb in the detrital fraction is held in discrete sulphide minerals. These minerals accumulate at the same rate as other detrital sedimentary material in response to the present depositional conditions. Non-detrital Zn, Cu, and Pb contributions represent the portion of the total element content adsorbed by fine grained inorganic and organic material during transport and deposition. The distributions of non-detrital Pb and to a lesser extent of Zn and Cu in the fjord are apparently controlled by the downstream dispersal from local industrial sources of mercury (Hg)-rich terrestrial organic matter.


1979 ◽  
Vol 16 (6) ◽  
pp. 1196-1209 ◽  
Author(s):  
D. H. Loring

Total Co (3–22 ppm), Ni (4–160 ppm), V (4–168 ppm), and Cr (8–241 ppm) concentrations vary regionally and with textural differences in the sediments of the St. Lawrence estuary and Gulf of St. Lawrence. They are, except for local anomalies, at or near natural levels relative to their source rocks and other marine sediments.Chemical partition and mineralogical analyses indicate that small but biochemically significant quantities (2–24%) of the total element concentrations are potentially available to the biota and are most likely held by fine-grained organic material, hydrous iron oxides, and ion exchange positions in the sediments. In the upper estuary, nondetrital Ni, Cr, and V supplied from natural and anthropogenic (Cr) sources are apparently preferentially scavenged from solution by terrestrial organic matter and hydrous oxides and concentrated in fine-grained sediments deposited below the turbidity maximum. In the lower estuary, the fine-grained sediments are relatively enriched in nondetrital V supplied from anthropogenic sources in the Saguenay system. Elsewhere the sedimentation intensities of the nondetrital elemental contributions have remained relatively constant with fluctuations in total sediment intensity.Seventy-six to 98% of the total Co, Ni, Cr, and V is not, however, available to the biota, but held in various sulphide, oxide, and silicate minerals. The host minerals have accumulated at the same rate as other fine-grained detrital material except for some local anomalies. In the upper estuary, detrital V concentrations are highest in the sands as an apparent result of an enrichment of ilmenite and titaniferous magnetite from a nearby mineral deposit. In the open gulf, relatively high concentrations of Ni, Cr, and V occur in sediments from the Bay of Islands, Newfoundland, and probably result from the seaward dispersal of detrital Ni, Cr, and V bearing minerals from nearby ultrabasic rocks.


1974 ◽  
Vol 52 (8) ◽  
pp. 1087-1090 ◽  
Author(s):  
David C. Judkins ◽  
Robert Wright

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.


2020 ◽  
Vol 17 (2) ◽  
pp. 547-566 ◽  
Author(s):  
Louise Delaigue ◽  
Helmuth Thomas ◽  
Alfonso Mucci

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.


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.


1979 ◽  
Vol 16 (2) ◽  
pp. 240-249 ◽  
Author(s):  
J. P. Chanut ◽  
S. A. Poulet

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.


1978 ◽  
Vol 15 (6) ◽  
pp. 1002-1011 ◽  
Author(s):  
Bjørn Sundby ◽  
Douglas H. Loring

Analysis of major elements in suspended particulate matter from the Saguenay Fjord in May and September 1974 shows that the content of Si, Al, Ca, Mg, and K remain relatively constant in time and space, reflecting the constancy of the silicate mineralogy of the particulate matter. Large variations in time and space occur, however, in the content of Fe and Mn. High levels of Fe occur in particulate matter from near-bottom waters of the fjord during both time periods. Variations in the Fe/Al ratios indicate that Fe is enriched in the non-silicate fraction of the particulate matter (oxides, hydroxides, etc.) in the near-bottom waters, but not elsewhere. In contrast, Mn is enriched relative to both Al and Fe in particulate matter from intermediate depths, and varies in time and space. This is attributed to the in situ uptake of Mn from seawater and (or) the input of particles, already containing high levels of Mn, from the St. Lawrence Estuary.


1990 ◽  
Vol 25 (1) ◽  
pp. 1-14
Author(s):  
R.J. Allan

Abstract The Saguenay Fjord enters the north shore of the St. Lawrence River estuary. The St. Lawrence River is one source of a variety of toxic metals and organic chemicals to its estuary. Some of these chemicals are transported by the river from its source in Lake Ontario and others are added along its course. However, the second major source of water inflow to the St. Lawrence Estuary is the Saguenay Fjord, which is by no means free of contamination. This paper overviews the types of toxic metals and organic chemical contamination and sources in the fjord proper and upstream in its drainage basin. The principal contaminants recorded in bottom sediments are polyaromatic hydrocarbons and mercury. An extensive forest products industry may also be a source of toxic chlorinated organic chemicals. The combined (peak) inputs of these chemicals to the Saguenay Fjord system was in the past and may have continued for many years, even decades. The relationship between the type of contaminants introduced in the past to the St. Lawrence estuary by the St. Lawrence River and the Saguenay Fjord may have implications concerning contamination of the beluga whale population which is located most frequently in the estuary near the fjord inflow.


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