Lake Acidification Recovery can be Monitored using Chrysophycean Microfossils

1989 ◽  
Vol 46 (8) ◽  
pp. 1309-1312 ◽  
Author(s):  
Sushil S. Dixit ◽  
Aruna S. Dixit ◽  
John P. Smol
Keyword(s):  
Low Ph ◽  
Lake Acidification ◽  
Metal Mining ◽  
Ph Change ◽  
Swan Lake ◽  
Acidification Recovery ◽  
Inferred Ph ◽  
Smelting Activity ◽  
Undisturbed Sediments ◽  
Mining And Smelting

Chrysophyte scales in a sediment core from Swan Lake, Sudbury, Ontario were studied to examine their sensitivity for inference of recent lakewater pH change. The study indicates that, corresponding to an increase in metal mining and smelting activity in the Sudbury basin, lake acidification commenced in 1940. However, as a result of reductions in SO2 emissions in the early 1970's, the lake's pH has recovered from its chronic low pH of 4.0 in 1977 to its high of 5.6 in 1987. The chrysophyte-inferred pH recovery mirrors the increase in measured lakewater pH. The study identifies the potential of chrysophytes to document recent pH recovery in soft-water lakes containing undisturbed sediments. The approach offers promise for understanding the response in lakes of poorly buffered regions to decreased atmospheric loadings of SO2 and in establishing and implementing SO2 mitigation standards.

scholarly journals Filament formation by metabolic enzymes is a specific adaptation to an advanced state of cellular starvation

2014 ◽  
Author(s):  
Ivana Petrovska ◽  
Elisabeth Nüske ◽  
Matthias C Munder ◽  
Gayathrie Kulasegaran ◽  
Liliana Malinovska ◽  
...  
Keyword(s):  
Metabolic Enzymes ◽  
Low Ph ◽  
General Mechanism ◽  
Filament Formation ◽  
Ph Change ◽  
Cooperative Process ◽  
A Cell ◽  
Enzymatic Inactivation ◽  
Physical Organization

One of the key questions in biology is how the metabolism of a cell responds to changes in the environment. In budding yeast, starvation causes a drop in intracellular pH, but the functional role of this pH change is not well understood. Here, we show that the enzyme glutamine synthetase (Gln1) forms filaments at low pH and that filament formation leads to enzymatic inactivation. Filament formation by Gln1 is a highly cooperative process, strongly dependent on macromolecular crowding, and involves back-to-back stacking of cylindrical homo-decamers into filaments that associate laterally to form higher order fibrils. Other metabolic enzymes also assemble into filaments at low pH. Hence, we propose that filament formation is a general mechanism to inactivate and store key metabolic enzymes during a state of advanced cellular starvation. These findings have broad implications for understanding the interplay between nutritional stress, the metabolism and the physical organization of a cell.

Common loon reproduction and chick feeding on acidified lakes in the Adirondack Park, New York

1988 ◽  
Vol 66 (4) ◽  
pp. 804-810 ◽  
Author(s):  
Karl E. Parker
Keyword(s):  
New York ◽  
Food Resource ◽  
Resource Depletion ◽  
Low Ph ◽  
Lake Acidification ◽  
Common Loon ◽  
Feeding Problems ◽  
Short Term ◽  
Lake Acidity ◽  
Adirondack Lakes

The effects of lake acidification on common loon reproduction were studied on a total of 24 Adirondack lakes from May through August in 1983 and 1984. The lakes ranged in size from 10.5 to 179 ha; pH ranged from 4.65 to 6.77 and alkalinity from −66 to 111 μequiv./L. Although loons nesting on small, low-pH lakes had a high fledging rate, possibly because of reduced disturbance or predation, no significant relationship (P > 0.10) was found between lake acidity status and loon reproductive success. No chick mortality could be attributed to lake acidification, but chicks on low-pH lakes were generally fed prey much smaller or much larger than those normally preferred. A pair nesting on a fishless lake fed aquatic insects to their constantly begging chick, spending two to four times longer feeding the chick compared with loons on lakes with fish. This pair, alternating absences, flew to another lake to feed, and on three occasions returned to the nesting lake carrying a fish. Loons on the low-pH study lakes apparently adapted, at least in the short term, to food resource depletion associated with acidification. Despite this, acidification creates potentially severe feeding problems for chicks by reducing prey diversity and quantity.

Palaeolimnological changes related to acid deposition and land-use in the catchments of two Norwegian soft-water lakes

1990 ◽  
Vol 327 (1240) ◽  
pp. 385-389 ◽  
Keyword(s):  
Land Use ◽  
Acid Deposition ◽  
Soft Water ◽  
The Other ◽  
Lake Acidification ◽  
Close Connection ◽  
Nitrogen Compounds ◽  
Atmospheric Contamination ◽  
High Acid ◽  
Inferred Ph

This is a palaeolimnological study of two Norwegian soft-water lakes, one receiving high, the other low, deposition of sulphur and nitrogen compounds. At the site with low acid deposition inferred pH has oscillated between 5.6 and 5.9 and there is little evidence of atmospheric contamination. At the site with high acid deposition, many centuries of stability are followed by a rapid acidification from pH around 5 in 1900 to the present (1986) level of pH 4.4. In this lake, the sedimentary record indicates a close connection between acid deposition and recent lake acidification.

scholarly journals pH Control in Recirculating Aquaculture Systems for Pāua (Haliotis iris)

2021 ◽  
Author(s):  
◽  
Jonathan P Wright
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Air Flow ◽  
Ph Control ◽  
Low Ph ◽  
Ph Change ◽  
Prismatic Layer ◽  
Industrial Grade ◽  
Recirculating Aquaculture Systems ◽  
Counter Current

<p>In high intensity recirculated aquaculture systems (RAS), metabolic carbon dioxide can accumulate quickly and have a significant impact on the pH of the culture water. A reduction in growth rate and increased shell deformation have been observed in farmed abalone that has been attributed to reduced pH levels that occur in RAS due to accumulation of CO2 in the culture water. The overall aim of this research programme was to assess two methods of pH control (physical vs. chemical) used in land-based aquaculture systems for the culture of the New Zealand abalone, pāua. In the first study the efficiency of physical carbon dioxide removal from seawater using a cascade column degassing unit was considered. Hydraulic loading, counter current air flow, packing media height, and water temperature were manipulated with the goal of identifying the most effective column configuration for degassing. Three influent water treatments were tested between a range of pH 7.4 to 7.8 (~3.2 to 1.2 mg L-1 CO2 respectively). For all influent CO2 concentrations the resulting pH change between influent and effluent water (immediately post column) were very low, the most effective configuration removed enough CO2 to produce a net gain of only 0.2 of a pH unit. Manipulating water flow, counter current air flow and packing media height in the cascade column had only minor effects on removal efficiency when working in the range of pH 7.4 – 7.8. A secondary study was undertaken to examine the effects on pāua growth of adding chemicals to increase alkalinity. Industrial grade calcium hydroxide (Ca(OH)2) is currently used to raise pH in commercial pāua RAS, however it is unknown if the addition of buffering chemicals affects pāua growth. Replicate pāua tanks were fed with seawater buffered with either sodium hydroxide, food grade Ca(OH)2 or industrial grade Ca(OH)2, with the aim of identifying the effects of buffered seawater on the growth of juvenile pāua (~30 mm shell length). Growth rate ([micrometre]/day) was not significantly affected by the addition of buffering chemicals into the culture water, and the continued use of industrial grade Ca(OH)2 is recommended for the commercial production of pāua in RAS. Shell dissolution is observed in cultured pāua reared in low pH conditions, however there is limited information surrounding the direct effect of lowered pH on the rate of biomineralisation and shell dissolution in abalone. A preliminary investigation was undertaken to examine shell mineralogy, the rate of biomineralisation and shell dissolution of pāua grown at pH 7.6 and 7.9 to determine their sensitivity to lowered pH. It was found that the upper prismatic layer of juvenile pāua shell (~40 mm) was composed almost exclusively of the relatively stable polymorph calcite, that suggests pāua are relatively tolerant to a low pH environment, compared to other abalone species that have proportionately more soluble aragonite in their prismatic layer. Regardless of shell composition, significant shell dissolution was observed in pāua reared in water of pH 7.6. Over the duration of the trial, the rate of mineralisation ([micrometre]/day) was significantly different between pāua reared in pH 7.6 and in pH 7.9 water. However, after a period of acclimation, low pH did not appear to effect rate of mineralisation in pāua.</p>

scholarly journals Spatial Distributions, Pollution Assessment, and Qualified Source Apportionment of Soil Heavy Metals in a Typical Mineral Mining City in China

2018 ◽  
Vol 10 (9) ◽  
pp. 3115 ◽  
Author(s):  
Li Hua ◽  
Xue Yang ◽  
Yajun Liu ◽  
Xiuli Tan ◽  
Yong Yang
Keyword(s):  
Heavy Metals ◽  
Ecological Risk ◽  
Principal Component ◽  
Pollution Assessment ◽  
Distribution Patterns ◽  
Metal Mining ◽  
Southeastern Part ◽  
The Mean ◽  
High Concentrations ◽  
Mining And Smelting

Daye is a city in China known for its rich mineral resources, with a history of metal mining and smelting that dates back more than 3000 years. To analyze the spatial distribution patterns, ecological risk, and sources of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) in soils, 213 topsoil samples were collected in the main urban area of Daye in September 2016. The mean concentrations of Cd, Cu, Pb, and Zn were higher than the corresponding background values, with the mean concentration of Cd being almost seven times its background value. Spatially, the high concentrations of Cd, Mn, Pb, and Zn were mainly concentrated in the southeastern part of the region due to nonferrous metal mining and smelting. However, the high concentrations of Co and Cu were concentrated in the central part of the study area, resulted from copper mining and smelting. The data of the geoaccumulation index showed that the contamination levels ranged from no pollution (Co, Cr, Mn, and Ni) to heavy contamination (Cd, Cu, and Pb). Ecological risk assessment showed that Cd posed a high, serious, and even severe ecological risk in 53.78% of the area of Daye. According to the results of the principal component analysis, mineral exploitation and smelting involving a variety of minerals (ES_M), mining exploitation, and smelting of copper ore (ES_C), and natural sources are the three main sources of heavy metals in these soils. Furthermore, the absolute principal component scores showed that 69.21% and 23.17% of the heavy metal concentrations were ascribed to ES_M and ES_C, respectively.

Soil Algal Colonization and Its Ecological Role in an Environment Polluted by Past Zn–Pb Mining and Smelting Activity

2010 ◽  
Vol 215 (1-4) ◽  
pp. 339-348 ◽  
Author(s):  
J. Cabala ◽  
O. Rahmonov ◽  
M. Jablonska ◽  
E. Teper
Keyword(s):  
Ecological Role ◽  
Smelting Activity ◽  
Mining And Smelting

scholarly journals pH Control in Recirculating Aquaculture Systems for Pāua (Haliotis iris)

2021 ◽  
Author(s):  
◽  
Jonathan P Wright
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Air Flow ◽  
Ph Control ◽  
Low Ph ◽  
Ph Change ◽  
Prismatic Layer ◽  
Industrial Grade ◽  
Recirculating Aquaculture Systems ◽  
Counter Current

<p>In high intensity recirculated aquaculture systems (RAS), metabolic carbon dioxide can accumulate quickly and have a significant impact on the pH of the culture water. A reduction in growth rate and increased shell deformation have been observed in farmed abalone that has been attributed to reduced pH levels that occur in RAS due to accumulation of CO2 in the culture water. The overall aim of this research programme was to assess two methods of pH control (physical vs. chemical) used in land-based aquaculture systems for the culture of the New Zealand abalone, pāua. In the first study the efficiency of physical carbon dioxide removal from seawater using a cascade column degassing unit was considered. Hydraulic loading, counter current air flow, packing media height, and water temperature were manipulated with the goal of identifying the most effective column configuration for degassing. Three influent water treatments were tested between a range of pH 7.4 to 7.8 (~3.2 to 1.2 mg L-1 CO2 respectively). For all influent CO2 concentrations the resulting pH change between influent and effluent water (immediately post column) were very low, the most effective configuration removed enough CO2 to produce a net gain of only 0.2 of a pH unit. Manipulating water flow, counter current air flow and packing media height in the cascade column had only minor effects on removal efficiency when working in the range of pH 7.4 – 7.8. A secondary study was undertaken to examine the effects on pāua growth of adding chemicals to increase alkalinity. Industrial grade calcium hydroxide (Ca(OH)2) is currently used to raise pH in commercial pāua RAS, however it is unknown if the addition of buffering chemicals affects pāua growth. Replicate pāua tanks were fed with seawater buffered with either sodium hydroxide, food grade Ca(OH)2 or industrial grade Ca(OH)2, with the aim of identifying the effects of buffered seawater on the growth of juvenile pāua (~30 mm shell length). Growth rate ([micrometre]/day) was not significantly affected by the addition of buffering chemicals into the culture water, and the continued use of industrial grade Ca(OH)2 is recommended for the commercial production of pāua in RAS. Shell dissolution is observed in cultured pāua reared in low pH conditions, however there is limited information surrounding the direct effect of lowered pH on the rate of biomineralisation and shell dissolution in abalone. A preliminary investigation was undertaken to examine shell mineralogy, the rate of biomineralisation and shell dissolution of pāua grown at pH 7.6 and 7.9 to determine their sensitivity to lowered pH. It was found that the upper prismatic layer of juvenile pāua shell (~40 mm) was composed almost exclusively of the relatively stable polymorph calcite, that suggests pāua are relatively tolerant to a low pH environment, compared to other abalone species that have proportionately more soluble aragonite in their prismatic layer. Regardless of shell composition, significant shell dissolution was observed in pāua reared in water of pH 7.6. Over the duration of the trial, the rate of mineralisation ([micrometre]/day) was significantly different between pāua reared in pH 7.6 and in pH 7.9 water. However, after a period of acclimation, low pH did not appear to effect rate of mineralisation in pāua.</p>

scholarly journals Long-Term Adaptation of Acidophilic Archaeal Ammonia Oxidisers Following Different Soil Fertilisation Histories

2021 ◽  
Author(s):  
Jun Zhao ◽  
Baozhan Wang ◽  
Xue Zhou ◽  
Mohammad Saiful Alam ◽  
Jianbo Fan ◽  
...  
Keyword(s):  
Community Composition ◽  
High Throughput Sequencing ◽  
Environmental Changes ◽  
Agricultural Soils ◽  
Terrestrial Ecosystems ◽  
Low Ph ◽  
Ph Change ◽  
Monooxygenase Gene ◽  
Ammonia Oxidising Archaea

AbstractAmmonia oxidising archaea (AOA) are ecologically important nitrifiers in acidic agricultural soils. Two AOA phylogenetic clades, belonging to order-level lineages of Nitrososphaerales (clade C11; also classified as NS-Gamma-2.3.2) and family-level lineage of Candidatus Nitrosotaleaceae (clade C14; NT-Alpha-1.1.1), usually dominate AOA population in low pH soils. This study aimed to investigate the effect of different fertilisation histories on community composition and activity of acidophilic AOA in soils. High-throughput sequencing of ammonia monooxygenase gene (amoA) was performed on six low pH agricultural plots originating from the same soil but amended with different types of fertilisers for over 20 years and nitrification rates in those soils were measured. In these fertilised acidic soils, nitrification was likely dominated by Nitrososphaerales AOA and ammonia-oxidising bacteria, while Ca. Nitrosotaleaceae AOA activity was non-significant. Within Nitrososphaerales AOA, community composition differed based on the fertilisation history, with Nitrososphaerales C11 only representing a low proportion of the community. This study revealed that long-term soil fertilisation selects for different acidophilic nitrifier communities, potentially through soil pH change or through direct effect of nitrogen, potassium and phosphorus. Comparative community composition among the differently fertilised soils also highlighted the existence of AOA phylotypes with different levels of stability to environmental changes, contributing to the understanding of high AOA diversity maintenance in terrestrial ecosystems.

Decreased Survival and Calcium Uptake by the Crayfish Orconectes virilis in Low pH

1980 ◽  
Vol 37 (3) ◽  
pp. 364-372 ◽  
Author(s):  
D. F. Malley
Keyword(s):  
Acid Rain ◽  
Lake Water ◽  
Calcium Uptake ◽  
Physiological Responses ◽  
Low Ph ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Molt Cycle ◽  
Experimental Lakes Area ◽  
Acidification Of Lake

As part of a study of the effects of the experimental whole-lake acidification of Lake 223 in the Experimental Lakes Area on the population of the crayfish Orconectes virilis physiological responses of adults from this population to low pH were examined in the laboratory. Crayfish survived pH 4.0 for 10 d when they were not moulting but suffered mortality when they were in postmolt stages. Postmolt crayfish held at pH 5.0 for 10 d survived but showed slower progression of molt cycle stages and of calcification of the exoskeleton than individuals held at pH 6.0 or in lake water at about pH 6.7. Uptake of Ca++ by postmolt crayfish measured by the use of 45Ca as a tracer was inhibited by pH below 5.75 and ceased altogether below pH 4.0 when these levels of acidity were applied acutely.Key words: Orconectes virilis, crayfish, molt cycle, mortality, pH, calcification, postmolt calcium uptake, acid rain, lake acidification

scholarly journals Filament formation by metabolic enzymes is a specific adaptation to an advanced state of cellular starvation

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Ivana Petrovska ◽  
Elisabeth Nüske ◽  
Matthias C Munder ◽  
Gayathrie Kulasegaran ◽  
Liliana Malinovska ◽  
...  
Keyword(s):  
Metabolic Enzymes ◽  
Low Ph ◽  
General Mechanism ◽  
Filament Formation ◽  
Ph Change ◽  
Cooperative Process ◽  
A Cell ◽  
Enzymatic Inactivation ◽  
Physical Organization

One of the key questions in biology is how the metabolism of a cell responds to changes in the environment. In budding yeast, starvation causes a drop in intracellular pH, but the functional role of this pH change is not well understood. Here, we show that the enzyme glutamine synthetase (Gln1) forms filaments at low pH and that filament formation leads to enzymatic inactivation. Filament formation by Gln1 is a highly cooperative process, strongly dependent on macromolecular crowding, and involves back-to-back stacking of cylindrical homo-decamers into filaments that associate laterally to form higher order fibrils. Other metabolic enzymes also assemble into filaments at low pH. Hence, we propose that filament formation is a general mechanism to inactivate and store key metabolic enzymes during a state of advanced cellular starvation. These findings have broad implications for understanding the interplay between nutritional stress, the metabolism and the physical organization of a cell.

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