Acidic Lakes Research Articles

Browning affects pelagic productivity in northern lakes by surface water warming and carbon fertilization.

Global change impacts important environmental drivers for pelagic gross primary production (GPP) in northern lakes, such as temperature, light, nutrient, and inorganic carbon availability. Separate and/or synergistic impacts of these environmental drivers on pelagic GPP remain largely unresolved. Here, we assess key drivers of pelagic GPP by combining detailed depth profiles of summer pelagic GPP with environmental and climatic data across 45 small and shallow lakes across northern Sweden (20 boreal, 6 subarctic, and 19 arctic lakes). We found that across lakes summer pelagic GPP was strongest associated with lake water temperatures, lake carbon dioxide (CO2 ) concentrations impacted by lake water pH, and further moderated by dissolved organic carbon (DOC) concentrations influencing light and nutrient conditions. We further used this dataset to assess the extent of additional DOC-induced warming of epilimnia (here named internal warming), which was especially pronounced in shallow lakes (decreasing 0.96°C for every decreasing m in average lake depth) and increased with higher concentrations of DOC. Additionally, the total pools and relative proportion of dissolved inorganic carbon and DOC, further influenced pelagic GPP with drivers differing slightly among the boreal, subarctic and Arctic biomes. Our study provides novel insights in that global change affects pelagic GPP in northern lakes not only by modifying the organic carbon cycle and light and nutrient conditions, but also through modifications of inorganic carbon supply and temperature. Considering the large-scale impacts and similarities of global warming, browning and recovery from acidification of lakes at higher latitudes throughout the northern hemisphere, these changes are likely to operate on a global scale.

Analysis of the Mechanism of Acid Mine Drainage Neutralization Using Fly Ash as an Alternative Material: A Case Study of the Extremely Acidic Lake Robule in Eastern Serbia

Acid mine drainage (AMD) is a waste from mining sites, usually acidic, with high concentrations of sulfates and heavy metal ions. This study investigates the AMD neutralization process using fly ash (FA) as an alternative material. Samples of FA from coal-fired power plants in Serbia (“Nikola Tesla” (EF) and “Kostolac” (KOST)) were analyzed and used. The results were compared with the treatment efficiency of commercial neutralization agent (NaOH). The alkaline nature of FA was the basis for use in the treatment process of the extremely acid Lake Robule (pH 2.46), located in the mining areas of eastern Serbia. The optimal S/L ratio for the AMD neutralization process determined for EF was 25 wt.%, and for KOST it was 20 wt.%. The mechanism of the neutralization process was analyzed using the ANC test and PHREEQC program. The element concentrations and pH values in solutions indicated that FA samples could neutralize Lake Robule with more than 99% of Al, Fe, Cu, Zn, and more than 89% of Pb precipitated. Formation of insoluble (oxy)hydroxide forms (Fe3+ and Al3+ ions) creates favorable conditions for co-precipitation of other trace metals (Cu, Zn, Ni, Pb, and Cd) from AMD, which is further enhanced by cation adsorption on FA particles. FA proved to be a more effective neutralization agent than NaOH due to its adsorption effect, while among the FA samples, KOST was more effective due to the aging process through the carbonization reaction. Using FA as an alternative material is a promising and sustainable method for treating AMD, with economic and environmental benefits.

Morphostructure and Hydrogeochemical Analysis of Geothermal Systems in Karaha Bodas and Talaga Bodas Field, West Java

The Karaha Bodas and Talaga Bodas are two geothermal fields which are located in Tasikmalaya, West Java. The Karaha Bodas and Talaga Bodas fields have geothermal prospects with the discovery of several surface manifestations in the form of hot springs, fumaroles, and acid lakes. The orientation of the structure that developed in the two fields showed a different orientation. However, no research explains the relationship between the geothermal system in the Karaha Bodas field and the Talaga Bodas field, and the potential of Cipacing and Pamoyanan. The survey location is in Garut and Tasikmalaya, West Java. The investigation method used is qualitative (morphostructure analysis) and quantitative (hydrogeochemical analysis) methods. Data processing using DEM (Digital Elevation Model) for morphostructure analysis, and water chemistry from the Karaha Bodas, Talaga Bodas, and Cipacing fields for hydrogeochemical analysis. The analysis shows that the relationship between the Karaha Bodas and Talaga Bodas geothermal systems is typical a geothermal system, with having two different heat sources, the Talaga Bodas field as an upflow zone, and the Karaha Bodas field with Cipacing and Pamoyanan potentials as an outflow zone.Keywords: Conceptual model, geothermal system, hydrogeochemical, Karaha Bodas, morphostructure, Talaga Bodas.

Decoupling of chemical and biological recovery from acidification in a montane lake, Vermont, USA

Decoupling of chemical and biological recovery from acidification in a montane lake, Vermont, USA

Discovery of novel enzymes from extreme environments through metagenomic approaches: A mini-review

Extremophilic microorganisms are able to survive under extreme conditions of temperature, pH, salinity and pressure, such as hypersaline soils, hydrothermal vents, acidic coal mines and soda lakes. These microorganisms have special genetic and physiological modifications to survive under abiotic and biotic stresses. Extremozymes are considered as an important source for different industrial and biotechnological applications. With the advent of meta-omics approaches, the discovery of novel enzymes has accelerated. Using function- and sequence-based metagenomics, a large number of enzymes have been identified and characterized directly from extreme environments. Many extremozymes such as proteases, amylases, esterases, cellulases, chitinases, oxidoreductases and hydrolases have special properties to work at a wide range of salt, pH and temperature. In this review, the discovery and industrial applications of novel enzymes from extreme environments through metagenomic approaches have been discussed. We have also explained the screening methods of novel extremozymes through function- and sequence-based metagenomics.

Microbial community composition, and not pH, influences lake sediment function

AbstractLake sediment microbial communities vary across ecosystems and are often differentiated across pH. Additionally, these pH‐mediated differences in community composition are often correlated with changes in sediment functioning, such as methane and carbon dioxide production. However, few studies have experimentally tested pH effects on community assembly or considered how microbial community composition influences ecosystem function independent of differences in the environment. We used common garden experiments to test hypotheses about how pH influences microbial community assembly and function in lake sediments. Using inoculum from three acidic lakes and three near‐neutral lakes, we found that both pH environment and inoculum source significantly influenced sediment microbial community assembly. However, inoculum source had a larger effect size for both the sediment methanogen and nonmethanogen communities, indicating important roles of dispersal and drift. Additionally, inoculum source, but not pH environment, significantly influenced sediment methane and carbon dioxide production. This research is one of the first to experimentally test the influence of pH on sediment microbial community composition, and in doing so, we show the community composition significantly influences sediment function independent of pH. Understanding how lake sediment microbial communities are influenced by environment is the first step toward mechanistically linking changes in community composition to ecosystem function, and we provide critical evidence for how changes in microbial community assembly with environmental change will likely alter carbon cycling in lake sediments.

Responses of a shallow temperate lake ecosystem to major late-Holocene terrestrial vegetation shifts

Major terrestrial vegetation shifts (MTVSs) resulting from either human activities or natural processes can exert substantial pressure on lakes mainly through impacts on catchment biogeochemical cycles and groundwater circulation. To better understand the links between terrestrial vegetation dynamics and lake ecosystem structure and functions over long temporal scales, in this study, we reconstructed the responses of shallow Lake Spore (N Poland) to major late-Holocene vegetation shifts. We combined newly acquired data from pollen and spores, Cladocera, TOC/N, δ13C, and δ15N analyses of bulk organic matter with the already published results from sediment dating and analyses of several biotic and geochemical proxies. Statistical analysis of the abundance data for all the major terrestrial pollen taxa and reconstruction of vegetation openness derived from the REVEALS model indicated five MTVSs, each followed by a change in the lake environment. Changes in Lake Spore trophic status at MTVS1 (~2.82 kyr BP) and MTVS2 (~2.17 kyr BP) were attributed to the reorganization of the catchment’s nutrient cycling associated with a decline (MTVS1) and subsequent regeneration (MTVS2) of deciduous tree stands in the area. A distinct drop in the CaCO3 content of the lake sediments that started at MTVS4 (~0.57 kyr BP) likely occurred due to the substantial depletion of the water calcium pool following an abrupt transition from a tree-dominated to an herb-dominated landscape. Our record also suggested slight lake acidification following a spread of Pinus sylvestris at MTVS1 (~2.82 kyr BP) and MTVS3 (~1.10 kyr BP) and a lake level rise concurrent with the sharp increase in landscape openness at MTVS4 (~0.57 kyr BP).

Stream-pit lake interactions in an abandoned mining area affected by acid drainage (Iberian Pyrite Belt)

Opencast mining of sulfide ore deposits may lead to the formation of anthropogenic acidic lakes with highly polluted waters. In these systems, it is crucial to understand the hydrological connections between surface and groundwater and their contribution to the pollutant load delivered to the downgradient streams. This study characterizes the interactions between surface and groundwater in an acidic pit lake using different geochemical tracers (i.e., REE and other trace metals). The San Telmo pit lake, located in one of the most pollutant sources of the Iberian Pyrite Belt (IPB), can be considered as a flow-through pit lake except during dry periods, when it behaves as a terminal lake due to lower inputs by surface waters and higher outputs by evaporation. Results based on geochemical tracers indicate that the main inputs to the pit lake come from surface waters, with minor groundwater inputs rich in As, Cr, Cu, Fe and Pb. The contaminant load released from the mining area is very high (e.g., median values of 520 kg/day of Fe and 38 kg/day of Zn), causing the degradation of the fluvial network downstream. Most of released pollutants come from waste dumps located at the W of the mining zone (~50–70% of Al, Cd, Mg, Mn, Ni, SO4 and Zn and > 70% for Cu, Cr, Fe and, V), while the contribution of the water coming out the pit lake and other dumps is much lower. Thus, remediation efforts to improve the area and fluvial courses downstream must focus on the W waste dumps.

Effects of freshwater acidification and countermeasures

Nowadays, pollution has become a serious problem with the development of industry and the exploitation of the earth’s resources. Acid rain and lake acidification caused by pollutants such as sulfur dioxide and nitric oxide has caused serious effects in many places. Nowadays people do not know the ecological influence of acidification, how to detect it and how it recovers. This paper examines the effects of acid rain on fish, plants and microorganisms in freshwater lakes, as well as how to detect acid rain and how to manage and recover from it. The results are not always clear, but there is a lot of evidence that acidification is changing lakes in many aspects, whether living or non-living things, small or widespread factors, acidified freshwater is no longer what it used to be. By examining those problems, people can protect the environment more effectively. Reducing the occurrence of acid rain and the damage it causes in the future. The significance of this paper is analyzing the ecological influence of acid rain, studying and discussing the negative impact on species, and giving some solutions for people, governments and companies for acidification. Furthermore, lake water self-cleaning is also considered in the solution as well. Acid rain causes acidification of the soil, which has a negative impact on agriculture. And it also damages the breeding environment of animals, reducing their reproductive success. For example, fish, microorganisms, and plants can be negatively affected by acidification of the lake water, even leading to extinction.

Dissolution of a submarine carbonate platform by a submerged lake of acidic seawater

Abstract. Submarine sinkholes are found on carbonate platforms around the world. They are thought to form and grow when groundwater interactions generate conditions corrosive to carbonate minerals. Because their morphology can restrict mixing and water exchange, the effects of biogeochemical processes can accumulate such that the sinkhole water properties considerably diverge from the surrounding ocean. Studies of sinkhole waters can therefore reveal new insights into marine biogeochemical cycles; thus sinkholes can be considered “natural laboratories” where the response of marine ecosystems to environmental variations can be investigated. We conducted the first measurements in recently discovered sinkholes on Luymes Bank, part of Saba Bank in the Caribbean Netherlands. Our measurements revealed a plume of gas bubbles rising from the seafloor in one of the sinkholes, which contained a constrained body of dense, low-oxygen ([O2] = 60.2 ± 2.6 µmol kg−1), acidic (pHT = 6.24 ± 0.01) seawater that we term the “acid lake”. Here, we investigate the physical and biogeochemical processes that gave rise to and sustain the acid lake, the chemistry of which is dominated by the bubble plume. We determine the provenance and fate of the acid lake's waters, which we deduce must be continuously flowing through. We show that the acid lake is actively dissolving the carbonate platform, so the bubble plume may provide a novel mechanism for submarine sinkhole formation and growth. It is likely that the bubble plume is ephemeral and that other currently non-acidic sinkholes on Luymes Bank have previously experienced acid lake phases. Conditions within the acid lake were too extreme to represent future marine environmental responses to anthropogenic CO2 emissions on human timescales but may reflect the impact of proposed schemes to mitigate climate change by the deliberate addition of CO2 and/or alkalinity to seawater. Other Luymes Bank sinkholes did host conditions analogous to projections for the end of the 21st century and could provide a venue for studies on the impacts of anthropogenic CO2 uptake by the ocean.

Coexistence of Lobelia dortmanna and Cladium mariscus, an ecological and paleobotanical study

Lobelia dortmanna L. (Lobeliaceae family) is an indicator species that is predominantly found in oligotrophic and acidic lakes. They are mainly distributed in northwestern Europe. Their occurrence in Poland is highly threatened by the increasing grade of human activity and environmental eutrophication; however, new sites of Lobelia were discovered in the last few decades, for example, in Lake Krzywce Wielkie situated in Bory Tucholskie National Park (BTNP), Poland. The existence of Lobelia in this lake was unexpected because Cladium mariscus was also found in the lake. Cladium has different ecological demands and is regarded as a species typical of calcareous habitats where calcium is found in abundance in the substrate. To explain the coexistence of both species in Krzywce Wielkie, pollen analysis of organic sediments was performed for four short cores collected from the littoral zone of the lake and for one long deep-water core. Additionally, macrofossil analysis was done for all the short cores. Pollen analysis revealed the existence of Cladium from the early Holocene period up to the present time. Pollen and seeds of Lobelia were found to be present since the beginning of the 20th century. Development of L. dortmanna and Myriophyllum alterniflorum populations and a decrease in the number of aquatic macrophytes in the eutrophic water indicate oligotrophication of water. This process started following the construction of drainage canal and the consequent water level decrease. This situation can be attributed to the abandonment of the agricultural areas adjoining the lake, which causes a decrease in the inflow of nutrients into the lake. Development of pine forest and establishment of BTNP enabled the protection and conservation of the surrounding catchment areas, thus restricting the potential eutrophication of the habitats.

High Mercury Concentrations of European Perch (Perca fluviatilis) in Boreal Headwater Lakes with Variable History of Acidification and Recovery

High dissolved organic carbon and low pH are often associated with elevated mercury content of fish in boreal lakes, but less is known about the fish mercury dynamics in lakes recovering from acidification stress. We measured total mercury concentration (THg) in muscle of European perch (Perca fluviatilis) and evaluated the overall correlation with environmental and growth variables in 24 boreal headwater lakes in the 2010s. We found negative correlations of length-corrected perch THg with lake pH and perch growth, but no correlation with dissolved organic carbon. The main emphasis in the present study was focused to a subset of ten lakes in southern Finland with known perch THg during severe acidification in the 1980–1990s. The comparison of perch THg concentrations in the 2010s with values determined in the 1980–1990s showed a sharp increase in most acidic lakes where the perch populations suffered from severe acid stress in the 1980s. This increase was attributed to growth condensation caused by sharp decrease in perch growth during recovery of reproduction capacity and the consequent increases in population densities of perch. Our results highlight the importance of perch growth rate and population density for understanding the variability of fish Hg in boreal headwater lakes, where recovery from acidification can lead to higher mercury concentration of fish in certain cases.

Draft Genome Sequences of Acidithrix sp. Strain C25 and Acidocella sp. Strain C78, Acidophiles Isolated from Iron-Rich Pelagic Aggregates (Iron Snow).

ABSTRACTWe report the draft genome sequences of two acidophiles, the Fe-oxidizing bacterium Acidithrix sp. strain C25 and the putative Fe-reducing Acidocella sp. strain C78. Both strains were isolated from iron-rich pelagic aggregates (iron snow) collected below the redoxcline at a 5-m depth in an acidic pit lake located in Germany (51°31′8.2″N, 13°41′34.7″E).

Insights into Autotrophic Activities and Carbon Flow in Iron-Rich Pelagic Aggregates (Iron Snow).

Pelagic aggregates function as biological carbon pumps for transporting fixed organic carbon to sediments. In iron-rich (ferruginous) lakes, photoferrotrophic and chemolithoautotrophic bacteria contribute to CO2 fixation by oxidizing reduced iron, leading to the formation of iron-rich pelagic aggregates (iron snow). The significance of iron oxidizers in carbon fixation, their general role in iron snow functioning and the flow of carbon within iron snow is still unclear. Here, we combined a two-year metatranscriptome analysis of iron snow collected from an acidic lake with protein-based stable isotope probing to determine general metabolic activities and to trace 13CO2 incorporation in iron snow over time under oxic and anoxic conditions. mRNA-derived metatranscriptome of iron snow identified four key players (Leptospirillum, Ferrovum, Acidithrix, Acidiphilium) with relative abundances (59.6–85.7%) encoding ecologically relevant pathways, including carbon fixation and polysaccharide biosynthesis. No transcriptional activity for carbon fixation from archaea or eukaryotes was detected. 13CO2 incorporation studies identified active chemolithoautotroph Ferrovum under both conditions. Only 1.0–5.3% relative 13C abundances were found in heterotrophic Acidiphilium and Acidocella under oxic conditions. These data show that iron oxidizers play an important role in CO2 fixation, but the majority of fixed C will be directly transported to the sediment without feeding heterotrophs in the water column in acidic ferruginous lakes.

Drought coincident with aeolian activity in a Great Lakes coastal dune setting during the Algoma Phase (3.1–2.4 ka), southwest Michigan

Aeolian studies of Lake Michigan’s coastal dunes have yet to elucidate what factors control their episodic activity over the past 5000 years. High lake levels exposing sand along with increased storminess is generally accepted for high perched dunes. This hypothesis, however, remains poorly tested for low perched dunes along the southeast Lake Michigan coastline. Here, small lakes in the lee of dune complexes contain aeolian sand and various biological proxies. Age and sedimentation rate models from Gilligan Lake cores guide analysis of aeolian sand, charcoal, pollen, and diatoms at high resolution (1 cm [10.4 yr/cm]) during the high-water Algoma Phase (3.1–2.4 ka) of the upper Great Lakes. The diatoms record a transition from a deep, more acidic lake to a shallower, more alkaline lake with fewer wetlands. This transition is accompanied by a stepped increase in the amount of aeolian sand. There is a weak correlation (R2 0.5, p < 0.01) between increasing abundances of charcoal chunks and sand. Peaks of sand follow peaks in charcoal threads and sheets, suggesting fire played a role in removing vegetation, presaging the landscape for increases in storminess. Arboreal pollen records a transition from a mesic forest Fagus-Acer-Quercus-Abies assemblage suggestive of moister conditions to one richer in mesic hardwoods tolerant of drier conditions. Together, the environmental proxy data record a shallowing lake concomitant with increasing aeolian sand, suggesting that drought-like conditions along the coastline conditioned the landscape for renewed aeolian activity. Once initiated, increased storminess and shoreline erosion maintained dune activity through increased sediment supply.

Changes in acidity, DOC, and water clarity of Adirondack lakes over a 30-year span

Lake surveys conducted in 1987–88 and 2018–19 show changes in the chemical and optical properties of Adirondack lakes recovering from acidification. Among chronically acidified lakes (1980s pH < 5.5, ANC < 0 µeq L−1), increases in pH and reductions in monomeric Al were accompanied by significant increases in light attenuation, DOC, and CDOM. DOC-specific dissolved color (CDOM:DOC) doubled over the 30-year span, and is the likely factor accounting for loss of water clarity in Adirondack lakes during recovery from acidification. Monitoring data (1994–2002) from a subset of these lakes show that reductions in light attenuation were accompanied by stronger thermal stratification and greater hypolimnetic oxygen depletion. Lakes most affected by acidification experienced greater loss of water clarity during recovery relative to moderately acidified lakes. These findings are consistent with the hypothesis that lake acidification resulted in a reduction in light attenuation by CDOM resulting in greater water clarity in acidified lakes, and that this process has been reversed following regional declines in sulfate deposition.

Ancient, Acidic Lakes May Have Harbored Life

A new analysis of South African sediments hints that acidic lakes may have leached minerals necessary for biotic life.

Taxonomic and functional analyses of intact microbial communities thriving in extreme, astrobiology-relevant, anoxic sites

BackgroundExtreme terrestrial, analogue environments are widely used models to study the limits of life and to infer habitability of extraterrestrial settings. In contrast to Earth’s ecosystems, potential extraterrestrial biotopes are usually characterized by a lack of oxygen.MethodsIn the MASE project (Mars Analogues for Space Exploration), we selected representative anoxic analogue environments (permafrost, salt-mine, acidic lake and river, sulfur springs) for the comprehensive analysis of their microbial communities. We assessed the microbiome profile of intact cells by propidium monoazide-based amplicon and shotgun metagenome sequencing, supplemented with an extensive cultivation effort.ResultsThe information retrieved from microbiome analyses on the intact microbial community thriving in the MASE sites, together with the isolation of 31 model microorganisms and successful binning of 15 high-quality genomes allowed us to observe principle pathways, which pinpoint specific microbial functions in the MASE sites compared to moderate environments. The microorganisms were characterized by an impressive machinery to withstand physical and chemical pressures. All levels of our analyses revealed the strong and omnipresent dependency of the microbial communities on complex organic matter. Moreover, we identified an extremotolerant cosmopolitan group of 34 poly-extremophiles thriving in all sites.ConclusionsOur results reveal the presence of a core microbiome and microbial taxonomic similarities between saline and acidic anoxic environments. Our work further emphasizes the importance of the environmental, terrestrial parameters for the functionality of a microbial community, but also reveals a high proportion of living microorganisms in extreme environments with a high adaptation potential within habitability borders.4ky3Zi4SfdfTiNhAX3nKcyVideo abstract

The legacy of regional industrial activity: Is loon productivity still negatively affected by acid rain?

Metal mining and smelting in Sudbury, Ontario, Canada, began in the 1880s and peaked in the 1950s and 1960s. By the mid-1970s, thousands of lakes had been acidified by sulfur dioxide (SO2) emitted from Sudbury metal smelters. Common loons (Gavia immer) are top predators in lakes across Ontario, and lake acidification has resulted in loss of prey for developing chicks and declines in common loon breeding productivity. Acidifying emissions have declined greatly since the 1960s, but many lakes remain acidic. We evaluated chemical recovery and loon breeding success in 69 single-loon-pair (small), variably acidified lakes near Sudbury using 38 years of loon survey and water chemistry data (1982–2019). Lake pH increased, particularly in lakes that were more acidic and closer to Sudbury, but 65% of lakes that were highly acidic in the 1980s remained below pH 6.0 (where biological damage can occur) in 2019. Furthermore, over half of our study lakes showed hydrochemical properties indicative of acid impairment (e.g., high relative sulfate levels, low base cation concentrations, high aluminum and manganese concentrations). More acidic lakes were associated with lower loon productivity, and overall, loon breeding effort and success declined over four decades on these lakes. The legacy of acid rain continues to negatively impact small lakes near Sudbury, and we hypothesize that loons may be more vulnerable to population declines in areas throughout their range that were directly and heavily degraded due to acidifying emissions.

Ambio's legacy on monitoring, impact, and management of acid rain : This article belongs to Ambio's 50th Anniversary Collection. Theme: Acidification.

Early studies published in Ambio showed large-scale acidification of lakes in southern Sweden and Norway from acid rain. These studies were important for delimiting various scientific issues and thus for eventually contributing to legislation, which reduced emissions of sulfur dioxide and nitrogen oxides and helped to mitigate this major environmental problem. Long-term studies and monitoring in Sweden and Norway and at Hubbard Brook Experimental Forest in New Hampshire helped guide this legislation in Europe and in theUSA.