Recovery from acidification in Nova Scotia: temporal trends and critical loads for 20 headwater lakes

2006 ◽  
Vol 63 (7) ◽  
pp. 1504-1514 ◽  
Author(s):  
C J Whitfield ◽  
J Aherne ◽  
S A Watmough ◽  
P J Dillon ◽  
T A Clair
Keyword(s):  
Steady State ◽  
Nova Scotia ◽  
Critical Load ◽  
Temporal Trends ◽  
Acid Neutralizing Capacity ◽  
Headwater Lakes ◽  
Fab Model ◽  
Neutralizing Capacity ◽  
S Deposition ◽  
Critical Load Exceedance

The chemical response of 20 headwater lakes in Nova Scotia to reduced acid deposition was investigated using trend analysis, and the need for further reductions was assessed using two steady-state, critical load models. Significant decreases were observed in the concentration of nonmarine sulphate (SO42–) and hydrogen (H+) at four wet deposition monitoring stations across Atlantic Canada since 1984. Dominant trends in surface water were decreasing SO42– concentrations, with little improvement in alkalinity and H+. Based on the Steady State Water Chemistry (SSWC) and First-order Acidity Balance (FAB) models, and using a critical chemical limit for acid-neutralizing capacity of 20 µmolc·L–1, critical load is exceeded at 9 and 13 of the 20 study lakes, respectively. Application of the SSWC model suggests that sulphur (S) deposition must be reduced by 37.3 mmolc·m–2·year–1 from 1997 levels to prevent critical load exceedance at 95% of the study lakes. Using the FAB model, the minimum reductions in nitrogen and S deposition necessary to protect 95% of the study lakes are 32.7 and 42.1 mmolc·m–2·year–1, respectively. Additional reductions beyond those proposed for 2030 are required to minimize critical load exceedance and promote recovery in alkalinity and pH of surface waters at the study catchments.

scholarly journals Critical loads of sulphur and nitrogen for freshwaters in Great Britain and assessment of deposition reduction requirements with the First-order Acidity Balance (FAB) model

2000 ◽  
Vol 4 (1) ◽  
pp. 125-140 ◽  
Author(s):  
C. Curtis ◽  
T. Allott ◽  
J. Hall ◽  
R. Harriman ◽  
R. Helliwell ◽  
...  
Keyword(s):  
Great Britain ◽  
Water Chemistry ◽  
Critical Load ◽  
Acid Deposition ◽  
Critical Loads ◽  
Freshwater Ecosystems ◽  
Acid Neutralizing Capacity ◽  
First Order ◽  
Fab Model ◽  
S Deposition

Abstract. The critical loads approach is widely used within Europe to assess the impacts of acid deposition on terrestrial and freshwater ecosystems. Recent work in Great Britain has focused on the national application of the First-order Acidity Balance (FAB) model to a freshwaters dataset of 1470 lake and stream water chemistry samples from sites across Britain which were selected to represent the most sensitive water bodies in their corresponding 10 km grid square. A ``Critical Load Function" generated for each site is compared with the deposition load of S and N at the time of water chemistry sampling. The model predicts that when catchment processes reach steady-state with these deposition levels, increases in nitrate leaching will depress acid neutralizing capacity (ANC) below the critical threshold of 0 μeql-1 at more than a quarter of the sites sampled, i.e. the critical load of acid deposition is exceeded at these sites. The critical load exceedances are generally found in upland regions of high deposition where acidification has been previously recognised, but critical loads in large areas of western Scotland are also exceeded where little biological evidence of acidification has yet been found. There is a regional variation in the deposition reduction requirements for protection of the sampled sites. The FAB model indicates that in Scotland, most of the sampled sites could be protected by sufficiently large reductions in S deposition alone. In the English and Welsh uplands, both S and N deposition must be reduced to protect the sites. Current international commitments to reduce S deposition throughout Europe will therefore be insufficient to protect the most sensitive freshwaters in England and Wales. Keywords: critical loads; acidification; nitrate; FAB model; acid deposition

scholarly journals Probabilistic relations between acid–base chemistry and fish assemblages in streams of the western Adirondack Mountains, New York, USA

2019 ◽  
Vol 76 (11) ◽  
pp. 2013-2026 ◽  
Author(s):  
Barry P. Baldigo ◽  
Scott D. George ◽  
Timothy J. Sullivan ◽  
Charles T. Driscoll ◽  
Douglas A. Burns ◽  
...  
Keyword(s):  
Brook Trout ◽  
Fish Assemblages ◽  
Acid Neutralizing Capacity ◽  
Total Biomass ◽  
Total Density ◽  
Adirondack Mountains ◽  
Acid Base ◽  
Late 20Th Century ◽  
Neutralizing Capacity ◽  
S Deposition

Surface waters across much of New York’s Adirondack Mountains were acidified in the late 20th century but began to recover following the 1990 amendments to the Clean Air Act. Little data, however, are available to characterize biological impacts and predict recovery of fish assemblages in streams of the region. Quantitative fish and chemistry surveys were completed in 47 headwater streams during summer 2014–2016 to develop logistic (probabilistic) models that characterize the status of contemporary fish assemblages and predict how different nitrogen (N) and sulfur (S) deposition loads may affect future fish assemblages. Models for inorganic monomeric aluminum (Ali) and richness ≥1 species and for acid neutralizing capacity (ANC) and total density >400 fish/0.1 ha, total biomass >1500 g/0.1 ha, brook trout (Salvelinus fontinalis) density >0 or >200 fish/0.1 ha, and brook trout biomass >1000 g/0.1 ha were suitable for evaluating community and population responses to changes in acid–base chemistry. Anticipated changes in national (US) secondary standards for atmospheric emissions of nitrogen oxides (NOx) and sulfur oxides (SOx) to achieve target N and S deposition loads will alter acid–base chemistry and the probabilities for observing various levels of fish metrics in streams across the region and elsewhere.

scholarly journals Rapid Recent Recovery from Acidic Deposition in Central Ontario Lakes

Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 10 ◽  
Author(s):  
Shaun A. Watmough ◽  
M. Catherine Eimers
Keyword(s):  
Acidic Deposition ◽  
Base Cation ◽  
Acid Neutralizing Capacity ◽  
Chemical Recovery ◽  
Charge Balance ◽  
Limited Effect ◽  
Lake Recovery ◽  
Neutralizing Capacity ◽  
Carbon Concentrations ◽  
S Deposition

In many regions, chemical recovery in lakes from acidic deposition has been generally slower than expected due to a variety of factors, including continued soil acidification, climate-induced sulphate (SO4) loading to lakes and increases in organic acidity. In central Ontario, Canada, atmospheric sulphur (S) deposition decreased by approximately two-thirds between 1982 and 2015, with half of this reduction occurring between 2005 and 2015. Chemical recovery in the seven lakes was limited prior to 2005, with only small increases in pH, Gran alkalinity and charge-balance ANC (acid-neutralizing capacity). This was because lake SO4 concentrations closely followed changes in S deposition, and decreases in base cation concentration closely matched declines in SO4. However, decreases in S deposition and lake SO4 were more pronounced post-2005, and much smaller decreases in lake base cation concentrations relative to SO4 resulted in large and rapid increases in pH, alkalinity and ANC. Dissolved organic carbon concentrations in lakes increased over the study period, but had a limited effect on lake recovery. Clear chemical recovery of these lakes only occurred after 2005, coinciding with a period of dramatic declines in S deposition.

Chemical Responses of Acidic Lakes in the Sudbury, Ontario, Area to Reduced Smelter Emissions, 1981–89

1992 ◽  
Vol 49 (S1) ◽  
pp. 25-32 ◽  
Author(s):  
W. Keller ◽  
J. Roger Pitblado ◽  
J. Carbone
Keyword(s):  
Water Quality ◽  
Temporal Trends ◽  
Strong Support ◽  
Acid Neutralizing Capacity ◽  
Quality Improvements ◽  
Acidic Lakes ◽  
Neutralizing Capacity ◽  
Sulphur Emissions ◽  
Aquatic Acidification ◽  
Smelter Emissions

Monitoring of acidic lakes in the Sudbury, Ontario, area showed that general changes in water quality (increases in pH and acid-neutralizing capacity; decreases in concentrations of SO42−, Ca2+, Mg2+, Al, and Mn) have continued through the mid-1980's, following substantial reductions in sulphur emissions from area smelters in the late 1970's. By the late 1980's, these trends had levelled off, or even reversed in some lakes. No general, temporal trends were evident during the 1980's for concentrations of Cu, Ni, or Zn, metals directly associated with the smelter emissions. The widespread water quality improvements seen in lakes of the Sudbury area provide very strong support for the use of source controls to combat aquatic acidification. However, the fact that many Sudbury area lakes are still highly acidic and metal contaminated demonstrates that additional emission controls, which are being implemented, are essential in this region.

Organochlorine Residues in Brook Trout and Yellow Perch From New Brunswick and Nova Scotia (Canada) Lakes

1987 ◽  
Vol 22 (3) ◽  
pp. 352-364
Author(s):  
R. Peterson ◽  
S. Ray
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Brook Trout ◽  
Yellow Perch ◽  
Intensive Agriculture ◽  
Fish Tissues ◽  
North Central ◽  
Ddt Metabolites ◽  
Headwater Lakes

Abstract Brook trout and yellow perch collected while surveying New Brunswick and Nova Scotia headwater lakes were analyzed for DDT metabolites, chlordane, hexacyclohexane isomers, hexachlorobenzene, toxaphene and PCB’s. Concentrations of DDT metabolites were much higher from fish taken from lakes in north-central N.B. (200-700 ng/g wet wt) than from fish taken elsewhere (<10 ng/g). Seventy to 90% of the DDT metabolites was DDE. Chlordane (3-13 ng/g) was analyzed in seven trout, six of them from central N.B. areas with intensive agriculture. Isomers of hexachlorocyclohexane were in highest concentration from north-central N.B. (10-20 ng/g), eastern N.S. (5-15 ng/g) and southern N.B. (5-20 ng/g). In most cases, alpha-hexachlorocyclohexane (lindane) was the isomer in highest concentration. Concentrations of hexachlorobenzene in fish tissues was highly variable with no obvious geographic bias. PCB’s were detected in very few fish, and no toxaphene was detected.

Evaluation of Hemidesmus indicus root as an antacid by In vitro

2016 ◽  
Vol 5 (04) ◽  
pp. 4524
Author(s):  
Abdullah Shaikh Farooque ◽  
Md. Azharuddin Ismail Atar*
Keyword(s):  
Skin Diseases ◽  
Care Delivery ◽  
Health Care Delivery System ◽  
Acid Neutralizing Capacity ◽  
Standard Drug ◽  
Hemidesmus Indicus ◽  
Neutralizing Capacity ◽  
Loss Of Appetite ◽  
Powdered Drug

Medicinal plants are being widely used, either as single drug or in combination in health care delivery system. Indian Sarsaparilla, Hemidesmus indicus (Family: Asclepiadaceae) is a commonly known Indian Medicinal Plant, which is widely recognized in traditional systems of Medicine. It contains various phytoconstituents belonging to the category glycosides, flavonoids, tannins, sterols and volatile oils. It has been reported as useful in biliousness, blood diseases, dysentery, diarrhea, respiratory disorders, skin diseases, syphilis, fever, leprosy, leucoderma, leucorrhoea, itching, bronchitis, asthma, eye diseases, epileptic fits in children, kidney and urinary disorders, loss of appetite, burning sensation, dyspepsia, nutritional disorders, ulcer and rheumatism. Several studies are being carried towards its activities like analgesic, anti-inflammatory, antiulcer, hepatoprotective, antioxidant and helicobactericidal properties. In our study we have evaluated antacid activity of sariva (Anantmool) by using In-Vitro method, i.e. ANC (Acid Neutralizing Capacity). This evaluation was done by comparing the ANC of sariva macerated & powdered drug with water as blank & standard drug i.e. NaHCO3. Based on this In-Vitro experiment, we can conclude that, the macerated & powdered drug of sariva (Anantmool) evaluated in this study, varied in potency as measured in terms of their ANC. These results having ** i.e. P < 0.01 & Passed the normality test. However, the present study being in-vitro, the effects of antacid may vary In-Vitro; individual variations also contribute to the ultimate effectiveness of as antacid.        

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