Geochemistry of sediments in the back bay and Yellowknife Bay of the Great Slave Lake

Mudroch, A.; Joshi, S. R.; Sutherland, Diane G.; Mudroch, Paul; Dickson, K. M.

doi:10.1007/bf01740583

Cited by 37 publications

(18 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By contrast, arsenic and metal concentrations in the sediment core from Pocket Lake peaked later, in approximately 1970, after which concentrations declined and returned to pre-impact conditions. Sedimentary arsenic profiles from Yellowknife Bay, an embayment of Great Slave Lake at Yellowknife, more closely followed the emission history of Giant Mine, exhibiting increases in arsenic concentrations consistent with the initiation of mining operations at Giant Mine and peaking in approximately 1960 [27,28]. There are two competing hypotheses to explain the delayed peak in metal(loid)s in Pocket Lake: (i) post-depositional remobilization of metal(loid)s in the sediments interfere with the use of the sediment core from Pocket Lake as a historical archive of Giant Mine emissions; and (ii) the delayed peak in metal(loid) concentrations in Pocket Lake is related to retention in the catchment, providing a source of continued influx of metal (loid)s into Pocket Lake after atmospheric emission reductions.…”

Section: Methodsmentioning

confidence: 99%

“…During the full operational history of Giant Mine, an estimated 20 million kg of As 2 O 3 were released to the environment [25], and thus the legacy of contamination during the course of the Giant Mine operation is substantial. Increases in arsenic concentrations in sediment core profiles from Yellowknife Bay (Great Slave Lake), adjacent to the Giant Mine lease, have been reported consistent with the opening years of the mine in approximately 1950 [27,28], and arsenic remains elevated in surface waters within approximately 15 km of the mine (figure 1) [18,19].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake

et al. 2016

View full text Add to dashboard Cite

Giant Mine, located in the city of Yellowknife (Northwest Territories, Canada), is a dramatic example of subarctic legacy contamination from mining activities, with remediation costs projected to exceed $1 billion. Operational between 1948 and 2004, gold extraction at Giant Mine released large quantities of arsenic and metals from the roasting of arsenopyrite ore. We examined the long-term ecological effects of roaster emissions on Pocket Lake, a small lake at the edge of the Giant Mine lease boundary, using a spectrum of palaeoenvironmental approaches. A dated sedimentary profile tracked striking increases (approx. 1700%) in arsenic concentrations coeval with the initiation of Giant Mine operations. Large increases in mercury, antimony and lead also occurred. Synchronous changes in biological indicator assemblages from multiple aquatic trophic levels, in both benthic and pelagic habitats, indicate dramatic ecological responses to extreme metal(loid) contamination. At the peak of contamination, all Cladocera, a keystone group of primary consumers, as well as all planktonic diatoms, were functionally lost from the sediment record. No biological recovery has been inferred, despite the fact that the bulk of metal(loid) emissions occurred more than 50 years ago, and the cessation of all ore-roasting activities in Yellowknife in 1999.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake

et al. 2016

View full text Add to dashboard Cite

show abstract

“…One of the most toxic and bioaccessable forms of As, As 2 O 3 [51], is present abundantly in the lake sediments and streams in the Yellowknife area due to gold smelting associated with several mining operations, primarily the Giant Mine [36]. Previous research carried out on assessing the As levels in various mediums in the Yellowknife region suggest that current As background level in lake sediment is between ∼10 to 35 ppm [52][53][54] and can reach to 150 ppm in soil [55]. However, these studies also show that As level can reach extreme levels in soil (500 to 9300 ppm; [56,57]), lake sediment (1764 to 3821 ppm in the Baker Creek watershed; [58], and surface water samples (1500 to 20,400 μg/L; [59,60]).…”

Section: Arsenic Bioavailabilitymentioning

confidence: 98%

Lacustrine Arcellinina (Testate Amoebae) as Bioindicators of Arsenic Contamination

et al. 2016

View full text Add to dashboard Cite

Arcellininids (testate amoebae) were examined from 61 surface sediment samples collected from 59 lakes in the vicinity of former gold mines, notably Giant Mine, near Yellowknife, Northwest Territories, Canada to determine their utility as bioindicators of arsenic (As), which occurs both as a byproduct of gold extraction at mines in the area and ore-bearing outcrops. Cluster analysis (Q-R-mode) and detrended correspondence analysis (DCA) reveal five arcellininid assemblages, three of which are related to varying As concentrations in the sediment samples. Redundancy analysis (RDA) showed that 14 statistically significant environmental parameters explained 57 % of the variation in faunal distribution, while partial RDA indicated that As had the greatest influence on assemblage variance (10.7 %; p < 0.10). Stress-indicating species (primarily centropyxids) characterized the faunas of samples with high As concentrations (median = 121.7 ppm, max > 10000 ppm, min = 16.1 ppm, n = 32), while difflugiid dominated assemblages were prevalent in substrates with relatively low As concentrations (median = 30.2 ppm, max = 905.2 ppm, min = 6.3 ppm, n = 20). Most of the lakes with very high As levels are located downwind (N and W) of the former Giant Mine roaster stack where refractory ore was roasted and substantial quantities of As were released (as As2O3) to the atmosphere in the first decade of mining. This spatial pattern suggests that a significant proportion of the observed As, in at least these lakes, are industrially derived. The results of this study highlight the sensitivity of Arcellinina to As and confirm that the group has considerable potential for assessing the impact of As contamination on lakes.

show abstract

“…114°22′W) in Great Slave Lake, Canada. Maximum water depth in Yellowknife Bay is 40 m, but near the outlet of Baker Creek measures 2 to 15 m (Mudroch et al 1989). For the most part, water exiting Baker Creek flows in a southwesterly direction in Back Bay due to discharge from the Yellowknife River to the north.…”

Section: Fish Collectionmentioning

confidence: 99%

“…Higher concentrations of arsenic have been measured in sediments near the mouth and adjacent areas south of Baker Creek. Sediments and metals have been shown to accumulate in the shallow waters around Latham Island in Back Bay (Moore 1989;Mudroch et al 1989).…”

Section: Fish Collectionmentioning

confidence: 99%

Arsenic concentration and speciation in five freshwater fish species from Back Bay near Yellowknife, NT, CANADA

Rosemond

Xie

Liber

2008

Environ Monit Assess

View full text Add to dashboard Cite

The concentration of total arsenic and five different arsenic species [As(III), As(V), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AsB)], were measured in the muscle, liver and gastrointestinal tract (GIT) of five different fish species [lake whitefish (Coregonus clupeaformis), walleye (Stizostedion vitreum), northern pike (Esox lucius), white sucker (Catostomus commersoni) and longnose sucker (Catostomus catostomus)] from Back Bay, Great Slave Lake, near the city of Yellowknife, NT, Canada. The total concentration (dry weight) of arsenic in muscle ranged from 0.57 to 1.15 mg/kg, in the liver from 0.42 to 2.52 mg/kg and in the GIT from 1.48 to 8.92 mg/kg. Among fish species, C. commersoni had significantly higher total arsenic concentrations in the GIT than S. vitreum, E. lucius and C. clupeaformis, and higher total arsenic concentrations in the liver than C. clupeaformis. The mean concentration of As(III) and As(V) in the muscle of all fish ranged from < or =0.01 to 0.05 mg/kg and < or =0.01 to 0.02 mg/kg, respectively, and together comprised < or =7.5% of the total arsenic measured in muscle. The concentrations of MMA were below detection in the muscle of all five fish species. However, AsB and DMA were measured in all fish species and nearly all fish tissues. The concentrations of AsB ranged from 0.01 to 0.13 mg/kg and the concentrations of DMA ranged from <0.02 to 0.45 mg/kg. The majority (>50%) of organic arsenic in almost all of the tissues from fish caught in Back Bay was not directly identified. Evidence from the literature suggests that most of these other organic arsenic species were likely trimethylated arsenic compounds, however, further analytical work would need to be performed to verify this hypothesis.

show abstract

Geochemistry of sediments in the back bay and Yellowknife Bay of the Great Slave Lake

Cited by 37 publications

References 10 publications

Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake

Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake

Lacustrine Arcellinina (Testate Amoebae) as Bioindicators of Arsenic Contamination

Arsenic concentration and speciation in five freshwater fish species from Back Bay near Yellowknife, NT, CANADA

Contact Info

Product

Resources

About