Hypolimnion Injection of Nutrient Effluents as a Method for Reducing Eutrophication

1980 ◽  
Vol 37 (3) ◽  
pp. 320-327 ◽  
Author(s):  
D. W. Schindler ◽  
T. Ruszczynski ◽  
E. J. Fee
Keyword(s):  
Surface Waters ◽  
Standing Crop ◽  
Nutrient Concentrations ◽  
Precambrian Shield ◽  
Water Interaction ◽  
Anoxic Hypolimnion ◽  
Long Term Trends

Injection of nutrients into the anoxic hypolimnion of a small Precambrian Shield lake for 5 yr caused less of a eutrophication problem than discharging nutrients into surface waters. Phytoplankton standing crop and production in the whole lake averaged only 10–21% of values in a nearby lake fertilized at the surface. Five-year averages for the epilimnion only were still lower: 5–8% of those in the surface-fertilized lake. Analysis of long-term trends in chlorophyll and nutrient concentrations revealed much slower rates of increase than in surface-fertilized lakes.Key words: eutrophication, hypolimnion injection, sediment–water interaction, nutrients, experimental lakes

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

Long-term trends in nutrient concentrations in Polish coastal rivers

2015 ◽  
Vol 118 ◽  
pp. 37-46 ◽  
Author(s):  
Anna Jarosiewicz ◽  
Krystian Obolewski ◽  
Małgorzata Ożgo
Keyword(s):  
Nutrient Concentrations ◽  
Coastal Rivers ◽  
Long Term Trends

scholarly journals Seasonal variation in aragonite saturation in surface waters of Puget Sound – a pilot study

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Gregory Pelletier ◽  
Mindy Roberts ◽  
Mya Keyzers ◽  
Simone R. Alin
Keyword(s):  
Pilot Study ◽  
Surface Waters ◽  
Puget Sound ◽  
Phytoplankton Production ◽  
Carbonate System ◽  
Saturation State ◽  
Aragonite Saturation ◽  
Spatially Distributed ◽  
Long Term Trends

A pilot study of sampling, using monthly marine flights over spatially distributed stations, was conducted with the aim to characterize the carbonate system in Puget Sound over a full year-long period. Surface waters of Puget Sound were found to be under-saturated with respect to aragonite during October–March, and super-saturated during April–September. Highest pCO2 and lowest pH occurred during the corrosive October–March period. Lowest pCO2 and highest pH occurred during the super-saturated April–September period. The monthly variations in pCO2, pH, and aragonite saturation state closely followed the variations in monthly average chlorophyll a. Super-saturated conditions during April–September are likely strongly influenced by photosynthetic uptake of CO2 during the phytoplankton growing season. The relationship between phytoplankton production, the carbonate system, and aragonite saturation state suggests that long-term trends in eutrophication processes may contribute to trends in ocean acidification in Puget Sound.

scholarly journals Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

2016 ◽  
Author(s):  
M. Camino-Serrano ◽  
E. Graf Pannatier ◽  
S. Vicca ◽  
S. Luyssaert ◽  
M. Jonard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Atmospheric Deposition ◽  
Soil Solution ◽  
Surface Waters ◽  
European Forests ◽  
Icp Forests ◽  
Level Ii ◽  
Long Term Trends

Abstract. Dissolved organic carbon (DOC) in soil solution is connected to DOC in surface waters through hydrological flows. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site-studies has failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result from acidification recovery. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analys is at two levels: 1) to the entire European dataset and 2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC across Europe with temporal slopes of soil solution DOC ranging between −16.8 % yr−1 and +23 % yr−1 (median= +0.4 % yr−1). The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing DOC concentrations with increasing mean nitrate (NO3−) deposition and decreasing DOC concentrations with decreasing me an sulphate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduct ion of SO42− deposition could be confirmed in N-poorer forests, in agreement with observations in surface waters, this was not the case in N-richer forests. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.

scholarly journals Trends in nitrogen deposition and leaching in acid-sensitive streams in Europe

2001 ◽  
Vol 5 (3) ◽  
pp. 299-310 ◽  
Author(s):  
R. F. Wright ◽  
C. Alewell ◽  
J. M. Cullen ◽  
C. D. Evans ◽  
A. Marchetto ◽  
...  
Keyword(s):  
Surface Waters ◽  
Nitrogen Saturation ◽  
Inorganic Nitrogen ◽  
N Deposition ◽  
N Saturation ◽  
The Past ◽  
Run Off ◽  
Nitrate Concentrations ◽  
Long Term Trends

Abstract. Long-term records of nitrogen in deposition and streamwater were analysed at 30 sites covering major acid sensitive regions in Europe. Large regions of Europe have received high inputs of inorganic nitrogen for the past 20 - 30 years, with an approximate 20% decline in central and northern Europe during the late 1990s. Nitrate concentrations in streamwaters are related to the amount of N deposition. All sites with less than 10 kgN ha-1 yr-1 deposition have low concentrations of nitrate in streamwater, whereas all sites receiving > 25 kgN ha-1 yr-1 have elevated concentrations. Very few of the sites exhibit significant trends in nitrate concentrations; similar analyses on other datasets also show few significant trends. Nitrogen saturation is thus a process requiring many decades, at least at levels of N deposition typical for Europe. Declines in nitrate concentrations at a few sites may reflect recent declines in N deposition. The overall lack of significant trends in nitrate concentrations in streams in Europe may be the result of two opposing factors. Continued high deposition of nitrogen (above the 10 kgN ha-1 yr-1 threshold) should tend to increase N saturation and give increased nitrate concentrations in run-off, whereas the decline in N deposition over the past 5 – 10 years in large parts of Europe should give decreased nitrate concentrations in run-off. Short and long-term variations in climate affect nitrate concentrations in streamwater and, thus, contribute "noise" which masks long-term trends. Empirical data for geographic pattern and long-term trends in response of surface waters to changes in N deposition set the premises for predicting future contributions of nitrate to acidification of soils and surface waters. Quantification of processes governing nitrogen retention and loss in semi-natural terrestrial ecosystems is a scientific challenge of increasing importance. Keywords: Europe, acid deposition, nitrogen, saturation, recovery, water

scholarly journals Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

2016 ◽  
Vol 13 (19) ◽  
pp. 5567-5585 ◽  
Author(s):  
Marta Camino-Serrano ◽  
Elisabeth Graf Pannatier ◽  
Sara Vicca ◽  
Sebastiaan Luyssaert ◽  
Mathieu Jonard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Atmospheric Deposition ◽  
Soil Solution ◽  
Surface Waters ◽  
N Deposition ◽  
Icp Forests ◽  
Level Ii ◽  
Long Term Trends ◽  
Increasing Trends

Abstract. Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result of recovery from acidification. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analysis at two levels: (1) to the entire European dataset and (2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC. The rate change in soil solution DOC ranged between −16.8 and +23 % yr−1 (median  = +0.4 % yr−1) across Europe. The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing trends in DOC concentrations with increasing mean nitrate (NO3−) deposition and increasing trends in DOC concentrations with decreasing mean sulfate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduction of SO42− deposition could be confirmed in low to medium N deposition areas, in agreement with observations in surface waters, this was not the case in high N deposition areas. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.

Long-term trends in catchment export and lake concentrations of base cations in the Dorset study area, central Ontario

2008 ◽  
Vol 65 (5) ◽  
pp. 809-820 ◽  
Author(s):  
L A Molot ◽  
Peter J Dillon
Keyword(s):  
Surface Waters ◽  
Base Cations ◽  
Base Cation ◽  
Monovalent Cation ◽  
Eastern North America ◽  
Dry Period ◽  
Forested Catchments ◽  
Long Term Trends ◽  
High Runoff

Decreases in exchangeable base cation reservoirs, base cation export, and lake concentrations have been reported for acid-sensitive regions in Europe and eastern North America. These decreases have produced smaller than anticipated increases in alkalinity in surface waters in response to reductions in sulphate emissions and may have ecological consequences. This study presents annual export rates of Ca, Mg, K, and Na from 20 forested catchments between 1978 and 1998 and concentrations in seven downstream lakes between 1975 and 2005 in an acid-sensitive region of central Ontario, Canada. In contrast to monovalent cation export, decreases in divalent cation export continued after an extended dry period ended. Lake concentration trends showed three distinct periods. The first period (1975–1976 to 1982–1983) coincided with high runoff and was characterized by relatively high Ca, Mg, and K concentrations. This was followed by a 10-year period of fluctuations around the long-term mean. Concentrations then dropped below the long-term means and remained 5%–20% below the means until 2004–2005. The latter trend in lake concentrations suggests that export likely remained low but stable after May 1998 (the last month for which export data are available). Na increased between 250% and 350% in Dickie and Harp lakes as a result of road salt contamination.

Digital maps of hydrobionts and surface waters quality, the Baikal natural territory

2021 ◽  
Vol 967 (1) ◽  
pp. 2-12
Author(s):  
E.L. Lubsanova
Keyword(s):  
Water Pollution ◽  
Surface Waters ◽  
Aquatic Organisms ◽  
Blind People ◽  
Near Surface ◽  
Digital Maps ◽  
Long Term Trends ◽  
Constituent Elements ◽  
Natural Territory

The author provides information on a developed method of geoinformation mapping hydrobionts in order to automatize digital cartographic images formation with spatial-andtemporal distribution of species and long-term trends of freezing surface waters’quality changes at studying relationships in the functioning of hydrobiological communities. The features of technique with the description of technical stages for creating databases and constituent elements of geoinformation software by the example of designing a regional geoservice with interactive plankton-and-benthos-aquatic-organisms’ maps in the Baikal natural territory are presented. Signs mapping the classes of water pollution by hydrobiological indicators on points available for recognition by colour-blind people are offered to be applied in cartographic material. They are easily reproduced on objects near surface streams in cases of water pollution for warning the population.

Sign in / Sign up

Export Citation Format

Share Document