Influence of catchment topography on water chemistry in southeastern Québec Shield lakes

1997 ◽  
Vol 54 (10) ◽  
pp. 2215-2227 ◽  
Author(s):  
Pierre D'Arcy ◽  
Richard Carignan
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Surface Waters ◽  
Overland Flow ◽  
Canadian Shield ◽  
Chl A ◽  
Lake Water Chemistry ◽  
High Runoff ◽  
Shield Lakes

For 30 Canadian Shield lakes of southeastern Quebec, catchment slope and lake morphometry account for 50-70% of the variability of chlorophyll a (Chl a), dissolved organic carbon (DOC), total phosphorus (TP), NO3- , and NH4+ . Dissolved organic carbon, TP, Chl a, Ca, and Mg are negatively related to catchment slope, whereas NO3- and NH4+ increase with increasing slope. Concentrations of more conservative constituents (SO42-, Na, K) increase with decreasing elevation as a result of higher evapotranspiration and lower precipitation at low elevations. Catchment variables (slope, drainage area, percent wetlands) are as good predictors of Chl a (r2 = 0.7) as are water chemistry variables (TP, Ca, Mg, and pH). Dominant vegetation (deciduous vs. coniferous) has little or no influence on lake water chemistry. Hydrogeological data for the Canadian Shield suggest that, during periods of high runoff, the development of waterlogged areas and the importance of overland flow on saturated soils are inversely proportional to catchment slope. We propose that the strong influence of catchment slope on water quality is due to slope-dependent seasonal waterlogging, which determines the fate (retention or export to surface waters) of dissolved substances produced within and moving through the forest floor.

Diatom-inferred dissolved organic carbon reconstructions provide assessments of past UV-B penetration in Canadian Shield lakes

2001 ◽  
Vol 58 (3) ◽  
pp. 543-550 ◽  
Author(s):  
Sushil S Dixit ◽  
W (Bill) Keller ◽  
Aruna S Dixit ◽  
John P Smol
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Lake Water ◽  
Significant Proportion ◽  
Strong Relationship ◽  
Canadian Shield ◽  
Weighted Averaging ◽  
Calibration Data ◽  
Inference Models ◽  
Shield Lakes

Paleolimnological approaches have provided strong inference models for lake-water acidity and metal concentrations in Sudbury-area lakes, but calibration data have not yet been explored for inferring lake-water dissolved organic carbon (DOC). A review of available limnological data provided DOC values for 80 of our 105 calibration lakes, allowing us to examine the relative importance of DOC in determining the distribution of diatom assemblages in Canadian Shield lakes, such as those in the Sudbury region. Canonical correspondence analysis (CCA) indicated that lake-water DOC explained a significant proportion of variation in the diatom data. Our weighted-averaging DOC model showed a strong relationship (r2 = 0.63) between measured and inferred DOC. Using this model, we reconstructed historical DOC concentrations in three Sudbury-area lakes, and then estimated temporal changes in UV-B penetration. These reconstructions showed that lake water DOC concentrations and underwater UV-B penetration have changed markedly in two of the three lakes modeled. The close correspondence between inferred and measured DOC for the 1980s in all three lakes provides further evidence that we have accurately inferred DOC concentrations. Quantitative DOC reconstructions in Sudbury-area lakes offer an excellent technique for assessing past changes in DOC concentrations and UV-B penetration in Canadian Shield lakes.

Long-term trends in zooplankton of Dorset, Ontario, lakes: the probable interactive effects of changes in pH, total phosphorus, dissolved organic carbon, and predators

2008 ◽  
Vol 65 (5) ◽  
pp. 862-877 ◽  
Author(s):  
Norman D Yan ◽  
Keith M Somers ◽  
Robert E Girard ◽  
Andrew M Paterson ◽  
W. (Bill) Keller ◽  
...  
Keyword(s):  
Species Richness ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Phosphorus ◽  
Canadian Shield ◽  
Interactive Effects ◽  
Crustacean Zooplankton ◽  
Multiple Stressor ◽  
Zooplankton Communities ◽  
Shield Lakes

Time trends in abundance, body size, species richness, and species composition indicate that crustacean zooplankton communities of southern Canadian Shield lakes changed between 1980 and 2003. Total abundance did not decline despite reductions in total phosphorus, but all other metrics changed. Species richness declined in Harp Lake (Ontario, Canada) following its Bythotrephes invasion, but richness increased in three other lakes. Average cladoceran body length increased from 0.6 to 1.0 mm in seven of the lakes, as larger-bodied taxa replaced smaller ones. Correlations with water quality and fish metrics suggest that cladoceran size increases were attributable to many factors: a decline in food availability following declining phosphorus levels increasing the competitive advantage of larger herbivores, a decline in acidity favouring the larger, acid-sensitive daphniids, and reduced risk of planktivory linked to a rise in dissolved organic carbon levels and changes in predation regimes. Zooplankton communities on the Canadian Shield are changing, and these changes are best viewed in a multiple-stressor context. Key anthropogenic stressors have also changed and may do so again if Ca concentrations continue to decline.

Diatom-inferred dissolved organic carbon reconstructions provide assessments of past UV-B penetration in Canadian Shield lakes

2001 ◽  
Vol 58 (3) ◽  
pp. 543-550 ◽  
Author(s):  
Sushil S. Di×it ◽  
W. (Bill) Keller ◽  
Aruna S. Di×it ◽  
John P. Smol
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Canadian Shield ◽  
Shield Lakes

Logging-induced variations in dissolved organic carbon affect yellow perch (Perca flavescens) recruitment in Canadian Shield lakes

2007 ◽  
Vol 64 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Andrea Bertolo ◽  
Pierre Magnan
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Larval Survival ◽  
Canadian Shield ◽  
Lake Volume ◽  
Secondary Productivity ◽  
Shield Lakes ◽  
Positive Effect

There is increasing interest in the effects of allochthonous carbon on lake food webs. By temporarily increasing levels of dissolved organic carbon (DOC) in lakes, logging can help us understand how carbon from the watershed could affect lake biota. The goals of this study were to determine whether (i) logging has a significant effect on the abundance of young-of-the-year (YOY) yellow perch (Perca flavescens) in Canadian Shield lakes and (ii) any changes in yellow perch recruitment could be related to increases in nutrients (N and P) and (or) DOC following logging. To do this, we examined 22 Canadian Shield lakes: the watersheds of 13 were not impacted, while 9 underwent logging (1%–78% of the watershed area). We found that the relative abundance of YOY yellow perch increased after logging in proportion to the ratio between the area of the logged watershed and the lake volume. We show that this effect is likely explained by an increase in DOC following logging. This might be related to (i) an increase in secondary productivity due to a positive effect of terrestrial carbon on the microbial loop and (or) (ii) an increased hatching success and (or) larval survival due to a greater protection from UV radiation by DOC.

Effects of trophic status and wetland morphology, hydroperiod, and water chemistry on mercury concentrations in fish

2000 ◽  
Vol 57 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Joel W Snodgrass ◽  
Charles H Jagoe ◽  
A Lawrence Bryan, Jr. ◽  
Heather A Brant ◽  
J Burger
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Maximum Depth ◽  
Trophic Levels ◽  
Whole Body ◽  
Regression Analyses ◽  
Negative Effects ◽  
Depression Wetlands ◽  
Negative Effect

We sampled fish and selected water chemistry variables (dissolved organic carbon, sulfate, and pH) in nine southeastern depression wetlands to determine relationships among wetland morphology (surface area and maximum depth), hydrology, water chemistry, and bioaccumulation of mercury (Hg) in fishes. We concentrated on three fish species representing the range of trophic levels occupied by fish in southeastern depression wetlands. Whole-body Hg concentrations were lowest in lake chubsucker (Erimyzon sucetta), a benthic detritivore, and highest in redfin pickerel (Esox americanus americanus), a top carnivore. However, variation in Hg concentrations among wetlands was greater than variation among species. Regression analyses indicated that maximum depth and hydroperiod accounted for significant portions of variation among wetlands in standardized lake chubsucker and redfin pickerel Hg concentrations. Maximum depth and dissolved organic carbon had a negative effect on standardized Hg concentrations in mud sunfish (Acantharchus pomotis). Path analysis confirmed the results of regression analyses, with maximum depth and hydroperiod having relatively large direct negative effects on Hg concentrations. Our results suggest that leaching of Hg from sediments during the drying and reflooding cycle and binding of Hg species by dissolved organic carbon in the water column are primary factors controlling the bioavailability of Hg in southeastern depression wetlands.

scholarly journals Distribution and bacterial availability of dissolved neutral sugars in the South East Pacific

2008 ◽  
Vol 5 (4) ◽  
pp. 1165-1173 ◽  
Author(s):  
R. Sempéré ◽  
M. Tedetti ◽  
C. Panagiotopoulos ◽  
B. Charrière ◽  
F. Van Wambeke
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Surface Waters ◽  
Detectable Effect ◽  
Neutral Sugar ◽  
The South ◽  
East Pacific ◽  
Significant Stimulation ◽  
Order Of Magnitude ◽  
Neutral Sugars

Abstract. The distribution and bacterial availability of dissolved neutral sugars were studied in the South East Pacific from October to December 2004 during the BIOSOPE cruise. Four contrasting stations were investigated: Marquesas Islands (MAR), the hyper-oligotrophic South Pacific Gyre (GYR), the eastern part of the Gyre (EGY), and the coastal waters associated to the upwelling area off Chile (UPW). Total (free and combined) dissolved neutral sugar (TDNS) concentrations were in the same order of magnitude at MAR (387±293 nM), GYR (206±107 nM), EGY (269±175 nM), and UPW (231±73 nM), with the highest and lowest concentrations found at MAR (30 m, 890 nM) and EGY (250 m, 58 nM), respectively. Their contribution to dissolved organic carbon (TDNS-C×DOC−1%) was generally low for all sites varying from 0.4% to 6.7% indicating that South East Pacific surface waters were relatively poor in neutral sugars. Free dissolved neutral sugar (FDNS; e.g. sugars analyzed without hydrolysis) concentrations were very low within the detection limit of our method (5–10 nM) accounting for <5% of the TDNS. In general, the predominant sugars within the TDNS pool were glucose, xylose, arabinose, and galactose, while in the FDNS pool only glucose was present. TDNS stock to bacterial production ratios (integrated values from the surface to the deep chlorophyll maximum) were high at GYR with respect to the low primary production, whereas the opposite trend was observed in the highly productive area of UPW. Intermediate situations were observed for MAR and EGY. Bioavailability of dissolved organic matter (DOM) exposed to natural solar radiation was also experimentally studied and compared to dark treatments. Our results showed no or little detectable effect of sunlight on DOM bacterial assimilation in surface waters of UPW and GYR, while a significant stimulation was found in MAR and EGY. The overall results clearly suggest that DOM is less labile at GYR compared to UPW, which is consistent with the observed accumulation of dissolved organic carbon and the elevated C/N ratios reported by Raimbault et al. (2008).

scholarly journals Improved automation of dissolved organic carbon sampling for organic-rich surface waters

2016 ◽  
Vol 543 ◽  
pp. 44-51 ◽  
Author(s):  
Richard P. Grayson ◽  
Joseph Holden
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Surface Waters

scholarly journals Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

2016 ◽  
Vol 13 (6) ◽  
pp. 1863-1875 ◽  
Author(s):  
Zahra Thomas ◽  
Benjamin W. Abbott ◽  
Olivier Troccaz ◽  
Jacques Baudry ◽  
Gilles Pinay
Keyword(s):  
Water Quality ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Human Disturbance ◽  
Nutrient Dynamics ◽  
Agricultural Activity ◽  
Agricultural Catchments ◽  
The Impact ◽  
The Relationship

Abstract. Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43−) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and the probability of human disturbance provides a useful perspective for evaluating vulnerability of aquatic ecosystems and for managing systems to maintain agricultural production while minimizing leakage of nutrients.

Sign in / Sign up

Export Citation Format

Share Document