Chemical recovery and browning of Nova Scotia surface waters in response to declining acid deposition

2021 ◽  
Author(s):  
D. Redden ◽  
B. F. Trueman ◽  
D. W. Dunnington ◽  
L. E. Anderson ◽  
G. A. Gagnon
Keyword(s):  
Nova Scotia ◽  
Acid Deposition ◽  
Surface Waters ◽  
Chemical Recovery ◽  
Size Distributions ◽  
Iron Aluminum

Colour, pH, iron, and aluminum are increasing in NS surface waters; iron/aluminum size distributions include at least two colloidal fractions.

Identifying Sources of Sulfate Aerosols Reaching Whiteface Mountain, NY

1985 ◽  
Vol 43 ◽  
pp. 98-101
Author(s):  
James S. Webber
Keyword(s):  
Trace Metals ◽  
Acid Deposition ◽  
Surface Waters ◽  
Dry Deposition ◽  
Coal Combustion ◽  
Public Awareness ◽  
Sulfate Aerosols ◽  
Wet And Dry Deposition ◽  
Whiteface Mountain ◽  
Toxic Trace Metals

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.

scholarly journals Land use influences on acidification and recovery of freshwaters in Galloway, south-west Scotland

2001 ◽  
Vol 5 (3) ◽  
pp. 451-458 ◽  
Author(s):  
R. C. Helliwell ◽  
R. C. Ferrier ◽  
L. Johnston ◽  
J. Goodwin ◽  
R. Doughty
Keyword(s):  
Surface Waters ◽  
Chemical Recovery ◽  
Dry Period ◽  
Sulphur Deposition ◽  
South West ◽  
Recovery From Acidification ◽  
Long Term Trends ◽  
Acid Status ◽  
Annual Discharge

Abstract. The long term response of surface waters to changes in sulphur deposition and afforestation is investigated for three upland river systems in the Galloway region of south-west Scotland. From 1984-1999, these rivers exhibited a statistically significant decline in non-marine sulphate concentrations in response to reduced acid deposition. This reduction in non-marine sulphate was, however, insufficient to induce a pH recovery over the period. A statistically significant increase in river pH was observed between 1956-1970 (0.05 yr-1) when subsidised agricultural lime payments were at a maximum. In 1976, this subsidy ceased and surface waters have progressively acidified. In addition, climatic change is found to influence long-term trends in pH. Mean annual pH was greatest during a dry period between 1969-1973 when total annual discharge was low. Thereafter, pH declined gradually in response to higher rainfall and increased total annual discharge. Overall, surface waters draining the afforested catchments of the Rivers Cree and Bladnoch are more acid than those draining the moorland catchment of the Luce. These results indicate that in afforested catchments, current reductions in sulphur emissions have not led to an observed improvement in the acid status of surface waters. Forestry, therefore, represents a confounding factor with regard to chemical recovery from acidification in this region. Keywords: acidification, afforestation, deposition, rivers, lochs, non-marine sulphate, pH

scholarly journals Response of Bosmina size structure to the acidification and recovery of lakes near Sudbury, Canada

2016 ◽  
Vol 75 (s2) ◽  
Author(s):  
Andrew L. Labaj ◽  
Jennifer B. Korosi ◽  
Joshua Kurek ◽  
Adam Jeziorski ◽  
Wendel (Bill) Keller ◽  
...  
Keyword(s):  
Metal Contamination ◽  
Carapace Length ◽  
Size Structure ◽  
Chemical Recovery ◽  
Size Distributions ◽  
Environmental Controls ◽  
Invertebrate Predators ◽  
Successive Generations ◽  
Mining And Smelting ◽  
Acidification And Recovery

In response to biotic and abiotic cues, the cladoceran genus <em>Bosmina </em>can<em> </em>undergo changes in body size and appendage length and shape over successive generations. To improve our understanding of the environmental controls on <em>Bosmina</em> size structure, we used paleolimnological techniques to examine <em>Bosmina</em> size responses to the extreme acidification and metal contamination, and then subsequent chemical recovery, of lakes in the vicinity of mining and smelting operations near Sudbury, Canada. During the acidification period, <em>Bosmina </em>antennule and carapace length significantly increased in three of the five study lakes, while mucro length significantly decreased in four of the five lakes. However, despite the recent return to pre-impact pH levels, the size structure of the present-day <em>Bosmina</em> community still differs from the pre-impact size distributions. We suggest that the continued dominance of the food webs by small invertebrate predators (<em>e.g.</em>, cyclopoid copepods) is responsible for the persistent changes to <em>Bosmina</em> size structure.

The Effect of a Storm on an Inshore Area with Markedly Stratified Waters

1935 ◽  
Vol 1 (4) ◽  
pp. 227-237 ◽  
Author(s):  
H. B. Hachey
Keyword(s):  
Nova Scotia ◽  
North Atlantic ◽  
Surface Waters ◽  
South Coast ◽  
The South ◽  
Wind Action ◽  
Bottom Waters ◽  
Mixed Water

Coincident with the formation and subsequent movement of a North Atlantic cyclone following the characteristic track, offshore surface waters are forced to the south coast of Nova Scotia with consequent removal of intermediate and bottom waters. Wind action, as the storm approaches, intensifies the mixing of the waters. Markedly stratified waters are thus temporarily replaced by a body of thoroughly mixed water.

scholarly journals Modelling acidification, recovery and target loads for headwater catchments in Nova Scotia, Canada

2007 ◽  
Vol 11 (2) ◽  
pp. 951-963 ◽  
Author(s):  
C. J. Whitfield ◽  
J. Aherne ◽  
P. J. Dillon ◽  
S. A. Watmough
Keyword(s):  
Nova Scotia ◽  
Surface Waters ◽  
Dynamic Models ◽  
Model Simulation ◽  
Aquatic Organisms ◽  
Good Prognosis ◽  
Emissions Reductions ◽  
Critical Limit ◽  
Headwater Catchments ◽  
Magic Model

Abstract. The response of twenty acid-sensitive headwater catchments in Nova Scotia to acidic deposition was investigated for the period 1850–2100 using a dynamic hydrochemical model (MAGIC: Model of Acidification of Groundwater in Catchments). To ensure robust model simulation, MAGIC was calibrated to the long-term chemical trend in annual lake observations (13–20 years). Model simulations indicated that the surface waters of all twenty catchments acidified to the 1970s but showed subsequent recovery (increases in acid neutralising capacity (ANC) and pH) as sulphate deposition decreased. However, under proposed future emissions reductions (approximately 50% of current deposition) simulated ANC and pH will not return to estimated pre-industrial levels by 2100. An ANC of 20 μmolc L−1 and pH of 5.4 were defined as acceptable chemical thresholds (or critical chemical limits) for aquatic organisms in the current study. Under the proposed emissions reductions only one catchment is predicted to remain below the critical limit for ANC by 2100; three additional catchments are predicted to remain below the critical limit for pH. Dynamic models may be used to estimate target loads, i.e., the required deposition reductions to achieve recovery within a given time. Setting target loads at approximately 30% of current depositions would allow three of the four lakes to reach the chemical criteria by 2030. In contrast to the generally good prognosis for surface waters, soils lost an average of 32% of estimated initial base saturation and recovery is estimated to be very slow, averaging 23% lower than pre-acidification levels in 2100.

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