scholarly journals Interactive effects of copper and calcium in Daphnia pulex

2016 ◽  
Author(s):  
Andrew Liorti ◽  
Teresa Crease ◽  
Andreas Heyland
Keyword(s):  
Water Chemistry ◽  
Calcium Uptake ◽  
Anthropogenic Activities ◽  
Daphnia Pulex ◽  
Copper Toxicity ◽  
Radioactive Tracer ◽  
Interactive Effects ◽  
Natural Environments ◽  
Toxicity Screening ◽  
High Calcium

<p>Many freshwater habitats around the world suffered dramatic water chemistry changes over the last century mostly due to anthropogenic activities, including an overall reduction in pH due to high sulfur emissions and unsustainable forestry practices. One consequence of this change in water chemistry is a drop in available calcium concentration, which creates problems for aquatic organisms that rely on dissolved calcium to build their exo- or endoskeletons and reinforce their carapace during regular molts. <em>Daphnia</em> populations in shield lakes in northern Ontario are also exposed to other stressors, including copper, which persists at high concentrations in many of these freshwater lakes and ponds due to mining and other human activities. Copper toxicity on animals is influenced by the availability of other competing ions, such as calcium. Using our newly developed high throughput toxicity screening system, we show that mortality of <em>Daphnia pulex</em> increases with exposure to low calcium (0.05 mg L<sup>-1</sup>) and high copper (300 µg L<sup>-1</sup>). When these two stressors were combined, we found that copper was less toxic at high calcium concentrations, indicating a protective effect of calcium against copper toxicity. We then established basic calcium uptake kinetics in <em>D. pulex</em> using radioactive tracer <sub>45</sub>Ca and provide evidence that copper, at environmentally relevant concentrations, competes with calcium uptake based on K<sub>m</sub> and V<sub>max</sub>. Our data show that both calcium decline and copper increase in aquatic ecosystems may negatively impact natural <em>Daphnia</em> populations, and that interactions between these two metals may occur in natural environments that result in fitness consequences for zooplankton. </p>

scholarly journals Water Quality and Hydrogeochemical Characteristics of Some Karst Water Sources in Apuseni Mountains, Romania

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 857
Author(s):  
Maria-Alexandra Hoaghia ◽  
Ana Moldovan ◽  
Eniko Kovacs ◽  
Ionut Cornel Mirea ◽  
Marius Kenesz ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Chemistry ◽  
Major Ions ◽  
Anthropogenic Activities ◽  
Water Sources ◽  
Main Process ◽  
Karst Water ◽  
Rock Interaction ◽  
Apuseni Mountains ◽  
Karst Waters

Human activities and natural factors determine the hydrogeochemical characteristics of karst groundwaters and their use as drinking water. This study assesses the hydrogeochemical characteristics of 14 karst water sources in the Apuseni Mountains (NW Romania) and their potential use as drinking water sources. As shown by the Durov and by the Piper diagrams, the chemical composition of the waters is typical of karst waters as it is dominated by HCO3− and Ca2+, having a circumneutral to alkaline pH and total dissolved solids ranging between 131 and 1092 mg L−1. The relation between the major ions revealed that dissolution is the main process contributing to the water chemistry. Limestone and dolostone are the main Ca and Mg sources, while halite is the main Na and Cl source. The Gibbs diagram confirmed the rock dominance of the water chemistry. The groundwater quality index (GWQI) showed that the waters are of excellent quality, except for two waters that displayed medium and good quality status. The quality of the studied karst waters is influenced by the geological characteristics, mainly by the water–rock interaction and, to a more limited extent, by anthropogenic activities. The investigated karst waters could be exploited as drinking water resources in the study area. The results of the present study highlight the importance of karst waters in the context of good-quality water shortage but also the vulnerability of this resource to anthropogenic influences.

scholarly journals Ozone Response of Leaf Physiological and Stomatal Characteristics in Brassica juncea L. at Supraoptimal Temperatures

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
Jong Kyu Lee ◽  
Myeong Ja Kwak ◽  
Sang Hee Park ◽  
Han Dong Kim ◽  
Yea Ji Lim ◽  
...  
Keyword(s):  
Brassica Juncea ◽  
Agricultural Production ◽  
Stomatal Density ◽  
Anthropogenic Activities ◽  
Interactive Effects ◽  
Target Concentration ◽  
Stomatal Characteristics ◽  
Elevated O3 ◽  
Significant Difference ◽  
Supraoptimal Temperatures

Plants are affected by the features of their surrounding environment, such as climate change and air pollution caused by anthropogenic activities. In particular, agricultural production is highly sensitive to environmental characteristics. Since no environmental factor is independent, the interactive effects of these factors on plants are essential for agricultural production. In this context, the interactive effects of ozone (O3) and supraoptimal temperatures remain unclear. Here, we investigated the physiological and stomatal characteristics of leaf mustard (Brassica juncea L.) in the presence of charcoal-filtered (target concentration, 10 ppb) and elevated (target concentration, 120 ppb) O3 concentrations and/or optimal (22/20 °C day/night) and supraoptimal temperatures (27/25 °C). Regarding physiological characteristics, the maximum rate of electron transport and triose phosphate use significantly decreased in the presence of elevated O3 at a supraoptimal temperature (OT conditions) compared with those in the presence of elevated O3 at an optimal temperature (O conditions). Total chlorophyll content was also significantly affected by supraoptimal temperature and elevated O3. The chlorophyll a/b ratio significantly reduced under OT conditions compared to C condition at 7 days after the beginning of exposure (DAE). Regarding stomatal characteristics, there was no significant difference in stomatal pore area between O and OT conditions, but stomatal density under OT conditions was significantly increased compared with that under O conditions. At 14 DAE, the levels of superoxide (O2-), which is a reactive oxygen species, were significantly increased under OT conditions compared with those under O conditions. Furthermore, leaf weight was significantly reduced under OT conditions compared with that under O conditions. Collectively, these results indicate that temperature is a key driver of the O3 response of B. juncea via changes in leaf physiological and stomatal characteristics.

scholarly journals Resistance to Broad-Spectrum Antibiotics in Aquatic Systems: Anthropogenic Activities Modulate the Dissemination ofblaCTX-M-Like Genes

2012 ◽  
Vol 78 (12) ◽  
pp. 4134-4140 ◽  
Author(s):  
Marta Tacão ◽  
António Correia ◽  
Isabel Henriques
Keyword(s):  
Anthropogenic Activities ◽  
Resistant Bacteria ◽  
Natural Environments ◽  
M Gene ◽  
Extended Spectrum Beta Lactamase ◽  
Culture Independent ◽  
Microbiological Parameters ◽  
Clinical Environments ◽  
Environment Study ◽  
Resistant Strains

ABSTRACTWe compared the resistomes within polluted and unpolluted rivers, focusing on extended-spectrum beta-lactamase (ESBL) genes, in particularblaCTX-M. Twelve rivers from a Portuguese hydrographic basin were sampled. Physicochemical and microbiological parameters of water quality were determined, and the results showed that 9 rivers were classified as unpolluted (UP) and that 3 were classified as polluted (P). Of the 225 cefotaxime-resistant strains isolated, 39 were identified as ESBL-producing strains, with 18 carrying ablaCTX-Mgene (15 from P and 3 from UP rivers). Analysis of CTX-M nucleotide sequences showed that 17 isolates produced CTX-M from group 1 (CTX-M-1, -3, -15, and -32) and 1 CTX-M that belonged to group 9 (CTX-M-14). A genetic environment study revealed the presence of different genetic elements previously described for clinical strains. ISEcp1was found in the upstream regions of all isolates examined. Culture-independentblaCTX-M-like libraries were comprised of 16 CTX-M gene variants, with 14 types in the P library and 4 types in UP library, varying from 68% to 99% similarity between them. Besides the much lower level of diversity among CTX-M-like genes from UP sites, the majority were similar to chromosomal ESBLs such asblaRAHN-1. The results demonstrate that the occurrence and diversity ofblaCTX-Mgenes are clearly different between polluted and unpolluted lotic ecosystems; these findings favor the hypothesis that natural environments are reservoirs of resistant bacteria and resistance genes, where anthropogenic-driven selective pressures may be contributing to the persistence and dissemination of genes usually relevant in clinical environments.

scholarly journals A Mini-Review of Strategies for Quantifying Anthropogenic Activities in Microplastic Studies in Aquatic Environments

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 198
Author(s):  
Chun-Ting Lin ◽  
Ming-Chih Chiu ◽  
Mei-Hwa Kuo
Keyword(s):  
Anthropogenic Activities ◽  
Primary Source ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Watershed Scale ◽  
Effective Management ◽  
Potential Harm ◽  
Scale Measure ◽  
Management Policies ◽  
Gis Software

Microplastic pollution is no longer neglected worldwide, as recent studies have unveiled its potential harm to ecosystems and, even worse, to human health. Numerous studies have documented the ubiquity of microplastics, reflecting the necessity of formulating corresponding policies to mitigate the accumulation of microplastics in natural environments. Although anthropogenic activities are generally acknowledged as the primary source of microplastics, a robust approach to identify sources of microplastics is needed to provide scientific suggestions for practical policymaking. This review elucidates recent microplastic studies on various approaches for quantifying or reflecting the degree to which anthropogenic activities contribute to microplastic pollution. Population density (i.e., often used to quantify anthropogenic activities) was not always significantly correlated with microplastic abundance. Furthermore, this review argues that considering potential sources near sample sites as characteristics that may serve to predict the spatial distribution of microplastics in aquatic environments is equivocal. In this vein, a watershed-scale measure that uses land-cover datasets to calculate different percentages of land use in the watershed margins delineated by using Geographic Information System (GIS) software is discussed and suggested. Progress in strategies for quantifying anthropogenic activities is important for guiding future microplastic research and developing effective management policies to prevent microplastic contamination in aquatic ecosystems.

scholarly journals Interactive Effects of Copper Pipe, Stagnation, Corrosion Control, and Disinfectant Residual Influenced Reduction of Legionella pneumophila during Simulations of the Flint Water Crisis

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 730 ◽  
Author(s):  
Rebekah L. Martin ◽  
Owen R. Strom ◽  
Amy Pruden ◽  
Marc A. Edwards
Keyword(s):  
Water Chemistry ◽  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Interactive Effects ◽  
Residual Chlorine ◽  
Drinking Water Source ◽  
Corrosion Control ◽  
Copper Pipe ◽  
Chlorine Demand ◽  
Flint River

Flint, MI experienced two outbreaks of Legionnaires’ Disease (LD) during the summers of 2014 and 2015, coinciding with use of Flint River as a drinking water source without corrosion control. Using simulated distribution systems (SDSs) followed by stagnant simulated premise (i.e., building) plumbing reactors (SPPRs) containing cross-linked polyethylene (PEX) or copper pipe, we reproduced trends in water chemistry and Legionella proliferation observed in the field when Flint River versus Detroit water were used before, during, and after the outbreak. Specifically, due to high chlorine demand in the SDSs, SPPRs with treated Flint River water were chlorine deficient and had elevated L. pneumophila numbers in the PEX condition. SPPRs with Detroit water, which had lower chlorine demand and higher residual chlorine, lost all culturable L. pneumophila within two months. L. pneumophila also diminished more rapidly with time in Flint River SPPRs with copper pipe, presumably due to the bacteriostatic properties of elevated copper concentrations caused by lack of corrosion control and stagnation. This study confirms hypothesized mechanisms by which the switch in water chemistry, pipe materials, and different flow patterns in Flint premise plumbing may have contributed to observed LD outbreak patterns.

Influence of Water Chemistry on Size Structure of Zooplankton Assemblages

1990 ◽  
Vol 47 (10) ◽  
pp. 1937-1943 ◽  
Author(s):  
Alan J. Tessier ◽  
Richard J. Horwitz
Keyword(s):  
Water Chemistry ◽  
Significant Variation ◽  
Size Structure ◽  
Water Hardness ◽  
Hard Water ◽  
The Body ◽  
Zooplankton Abundance ◽  
High Calcium ◽  
Influence Of Water ◽  
Physical And Chemical

A stratified-random selection of all lakes in the northeastern United States was sampled for zooplankton composition, and physical and chemical characteristics during midsummer 1986. In all, 146 lakes were sampled from five geographic subregions and three categories of water alkalinity. There was no significant variation in total zooplankton abundance among regions or alkalinity categories; however, the body-size structure of assemblages was dependent on both alkalinity and geographic subregion. The largest change in size structure occurred at alkalinity levels > 150 μeq∙L−1 and pH > 7.0, and appeared less related to change in pH than to variation in water hardness. This shift of size structure was caused by a loss of large-bodied zooplankton and an increase in small rotifers with decreasing water hardness. Exploratory analysis revealed that lake stratification also explained significant variation in zooplankton size structure, but was largely independent of the effects of water chemistry. We hypothesize that the association of large zooplankton with hard water is casual; large-bodied cladocerans may require high calcium levels.

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