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 A Brief Review of the Structure, Cytotoxicity, Synthesis, and Biodegradation of Microcystins

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2147
Author(s):  
Anjali Krishnan ◽  
Xiaozhen Mou
Keyword(s):  
Health Hazard ◽  
Aquatic Organisms ◽  
Water Soluble ◽  
Cyanobacterial Blooms ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Exposure Pathway ◽  
Environmental Transformation ◽  
Cyclic Heptapeptide ◽  
Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms pose an environmental health hazard due to the release of water-soluble cyanotoxins. One of the most prevalent cyanotoxins in nature is microcystins (MCs), a class of cyclic heptapeptide hepatotoxins, and they are produced by several common cyanobacteria in aquatic environments. Once released from cyanobacterial cells, MCs are subjected to physical chemical and biological transformations in natural environments. MCs can also be taken up and accumulated in aquatic organisms and their grazers/predators and induce toxic effects in several organisms, including humans. This brief review aimed to summarize our current understanding on the chemical structure, exposure pathway, cytotoxicity, biosynthesis, and environmental transformation of microcystins.

scholarly journals Natural and human-induced factors controlling the phreatic groundwater geochemistry of the Longgang River basin, South China

2020 ◽  
Vol 12 (1) ◽  
pp. 203-219
Author(s):  
Wei Li ◽  
Xiaohong Chen ◽  
Linshen Xie ◽  
Gong Cheng ◽  
Zhao Liu ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
Chemical Evolution ◽  
South China ◽  
Major Ions ◽  
Negative Impact ◽  
Flow Direction ◽  
Anthropogenic Activities ◽  
Ionic Composition ◽  
Primary Source ◽  
Ammonia Concentration

AbstractGroundwater chemical evolution is the key to ensuring the sustainability of local society and economy development. In this study, four river sections and 59 groundwater wells are investigated in the Longgang River (L.R.) basin in South China. Comprehensive hydrochemical analysis methods are adopted to determine the dominant factors controlling the chemical evolution of the local phreatic groundwater and the potential impact of human activities on groundwater quality. The results indicate that the ionic composition of the local phreatic groundwater is dominated by Ca2+ (0.9–144.0 mg/L), HCO3− (4.4–280.0 mg/L), and SO42− (1.0–199.0 mg/L). Ca–Mg–HCO3, Ca–Na–HCO3, and Na–Ca–HCO3 are the major groundwater hydrochemical facies. Water–rock interactions, such as the dissolution of calcite and dolomite, are the primary source of the major ions in the local groundwater. Cation-exchange reaction has its effects on the contents of Ca2+, Mg2+, and Na+. Ammonia concentration of the sampling sections in the L.R. increases from 0.03 to 2.01 mg/L along the flow direction. Groundwater nitrate in the regions of the farmland is attributed to the lowest level of the groundwater quality standards of China, while the same test results are obtained for heavy metals in the industrial park and landfill, suggesting a negative impact of the anthropogenic activities on the local phreatic groundwater quality.

scholarly journals Aquatic environments in the One Health context: modulating the antimicrobial resistance phenomenon

2020 ◽  
Vol 32 ◽  
Author(s):  
Juliana Alves Resende ◽  
Vânia Lúcia da Silva ◽  
Claudio Galuppo Diniz
Keyword(s):  
Antimicrobial Resistance ◽  
One Health ◽  
Anthropogenic Activities ◽  
Treatment Strategies ◽  
Chemical Pollution ◽  
Resistant Bacteria ◽  
Aquatic Environments ◽  
Antimicrobial Substances ◽  
Antimicrobial Resistance Genes ◽  
The One

Abstract: From an anthropocentric perspective, aquatic environments are important to maintain health and survival, however, as they are sometimes managed based on misconception, they are considered a convergent pathway for anthropogenic residues and sanitation. Thus, it is observed that these ecosystems have been threatened by chemical pollution due to xenobiotics, especially from a more contemporary approach, by the selective pressure associated with antimicrobials. There are several studies that report the enrichment of antimicrobial resistant bacteria and mobilizable antimicrobial resistance genes in aquatic and adjacent ecosystems. From the perspective of the emerging and reemerging number of diseases related to the interplay of human, animal, and environmental factors, a new conception arose to address these issues holistically, which is known as the One Health approach. Scientific and political discourse on this conception should lead to effective action plans for preventing and controlling the spread of infectious diseases in open environment, including those impacted by anthropogenic activities. Therefore, nowadays, discussions on antimicrobial resistance are becoming broader and are requiring a multi-disciplinary view to address health and environmental challenges, which includes aquatic environment management. Water may represent one of the most important ecosystems for the in antimicrobial resistance phenomenon that arises when a dynamic and singular microbial community may be influenced by several characteristics. As antimicrobial substances do not all degrade at the same time under the same treatment, strategies concerning their removal from the environment should consider their individualized chemical characteristics.

scholarly journals Progress in remote sensing of aquatic environments at the watershed scale

2019 ◽  
Vol 38 (8) ◽  
pp. 1182-1195
Author(s):  
Hongtao DUAN ◽  
Juhua LUO ◽  
Zhigang CAO ◽  
Kun XUE ◽  
Qitao XIAO ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Aquatic Environments ◽  
Watershed Scale

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.

The chemical fractionation and potential source identification of Cu, Zn and Cd on urban watershed

2015 ◽  
Vol 72 (8) ◽  
pp. 1428-1436 ◽  
Author(s):  
Jin Zhang ◽  
Pei Hua ◽  
Peter Krebs
Keyword(s):  
Heavy Metals ◽  
Source Identification ◽  
Primary Source ◽  
Principal Component ◽  
Chemical Fractionation ◽  
Aquatic Environments ◽  
Extreme Conditions ◽  
Brake Pad ◽  
Urban Watershed ◽  
Potential Source

This study showcases the chemical fractionation and primary source identification of Cu, Zn and Cd in road-deposited sediment. Results show that Zn and Cd were identified as easily mobilised and biologically available metals that pose high risks to the receiving aquatic environments. However, Cu was released in substantial amounts only under relatively extreme conditions. With the assistance of principal component analysis and chemical fractionation, two primary contributors to heavy metals in road-deposited sediment were tentatively identified as vehicle-related sources (especially, auto brake pad erosion for Cu and tyre debris for Zn) and atmospheric deposition (especially for Cd).

scholarly journals Diversity of Antimicrobial-Resistant Aeromonas Species Isolated from Aquatic Environments in Brazil

2020 ◽  
Author(s):  
Danieli Conte ◽  
Jussara Kasuko Palmeiro ◽  
Adriane de Almeida Bavaroski ◽  
Luiza Souza Rodrigues ◽  
Daiane Cardozo ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Aquatic Ecosystems ◽  
Bacterial Resistance ◽  
Genetic Relatedness ◽  
Anthropogenic Activities ◽  
Treatment Plant ◽  
Aeromonas Species ◽  
Aquatic Environments ◽  
Antimicrobial Resistance Genes

ABSTRACTIn the present study, we characterized antimicrobial resistance profile and genetic relatedness of Aeromonas spp. isolated from healthcare and urban effluents, wastewater treatment plant (WWTP), and river water. We detected the presence of genes responsible for the resistance to β-lactam, quinolone, and aminoglycoside. Enterobacterial Repetitive Intergenic Consensus PCR and multilocus sequence typing (MLST) were carried out to differentiate the strains and multilocus phylogenetic analysis (MLPA) was used to identify species. A total of 28 Aeromonas spp. cefotaxime-resistant strains were identified that carried a variety of resistance determinants, including uncommon GES-type β-lactamases. Multidrug-resistant Aeromonas spp. were found in hospital wastewater, WWTP, and sanitary effluent. Among these isolates, we detected A. caviae producing GES-1 or GES-5, as well as A. veronii harboring GES-7 or GES-16. We successfully identified Aeromonas spp. by using MLPA and found that A. caviae was the most prevalent species (85.7%). In contrast, it was not possible to determine sequence type of all isolates, suggesting incompleteness of the Aeromonas spp. MLST database. Our findings reinforce the notion about the ability of Aeromonas spp. to acquire determinants of antimicrobial resistance from the environment. Such ability can be enhanced by the release of untreated healthcare effluents, in addition to the presence of antimicrobials, recognized as potential factors for the spread of resistance. Thus, Aeromonas spp. could be included as priority pathogens under the One Health concept.IMPORTANCEAeromonas species are native bacteria in aquatic ecosystems worldwide. However, they have also been isolated from humans and animals. Globally, aquatic environments have been affected by anthropogenic activities. For example, the excessive use of antimicrobials in medical and veterinary practice causes the development of bacterial resistance. In addition, eliminated hospital and sanitary effluents can also serve as potential sources of bacteria carrying antimicrobial resistance genes. Thereby, impacted environments play an important role in the transmission of these pathogens, their evolution, and dissemination of genes conferring resistance to antimicrobials. Aeromonas spp. have been reported as a reservoir of antimicrobial resistance genes in the environment. In this study, we identified a great repertoire of antimicrobial resistance genes in Aeromonas spp. from diverse aquatic ecosystems, including those that encode enzymes degrading broad-spectrum antimicrobials widely used to treat healthcare-associated infections. These are a public health threat as they may spread in the population.

scholarly journals Effects of Antibiotics on Impacted Aquatic Environment Microorganisms

2020 ◽  
Author(s):  
Lívia Caroline Alexandre de Araújo ◽  
Sivoneide Maria da Silva ◽  
Rafael Artur de Queiroz Cavalcanti de Sá ◽  
Ana Vitoria Araujo Lima ◽  
Amanda Virginia Barbosa ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Mass Production ◽  
Aquatic Environment ◽  
Human Medicine ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Natural Ecosystems ◽  
Composition And Structure ◽  
Hospital Effluents

Due to their mass production and intense consumption in human medicine, veterinary, and aquaculture, antibiotics have been widely detected in different ecosystems, leading to a growing worldwide concern. These and their byproducts are being continuously discarded in natural ecosystems via excretion of human and animal urine and feces, also domestic and hospital effluents. Residues of these drugs can persist in natural environments through bioaccumulation due to their difficult biodegradation. Also, they have a gradual deposition in sediments, aquatic surfaces, and groundwater. Studies have shown the presence of these drugs in aquatic environments, which can trigger severe changes in the composition and structure of the bacterial community, such as the ability to develop and propagate genes resistant to these pollutants. In this context, this review aims to address the effects of the antibiotics on microorganisms present in impacted aquatic environments.

scholarly journals Discontinuity in equilibrium wave–current ripple size and shape caused by a winnowing threshold in cohesive sand–clay beds

2021 ◽  
Author(s):  
Xuxu Wu ◽  
Roberto Fernández ◽  
Jaco Baas ◽  
Jonathan Malarkey ◽  
Dan Parsons
Keyword(s):  
Clay Content ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Flume Experiments ◽  
Sand Ripples ◽  
Sudden Release ◽  
Bed Roughness ◽  
Current Ripple ◽  
Sudden Reduction ◽  
Combined Flows

Sediments composed of mixed cohesive clay and non-cohesive sand are widespread in a range of aquatic environments. The dynamics of ripples in mixed sand–clay substrates have been studied under pure current and pure wave conditions. However, the effect of cohesive clay on ripple development under combined currents and waves has not been examined, even though combined flows are common in estuaries, particularly during storms. Based on a series of large flume experiments on ripple development under combined flows, we identified a robust inverse relationship between initial bed clay content, C0, and ripple growth rate. The experimental results also revealed two distinct types of equilibrium combined-flow ripples on mixed sand–clay beds: (a) large asymmetrical ripples with dimensions and plan geometries comparable to clean-sand counterparts for C0 ≤ 10.6%; and (b) small, flat ripples for C0 > 11%. The increase in bed cohesion contributed to this discontinuity, expressed most clearly in a sharp reduction in equilibrium ripple height, and thus a significant reduction in bed roughness, which implies that the performance of existing ripple predictors can be improved by the incorporation of this physical cohesive effect. These improvements are particularly important for sediment transport and morphodynamic models in muddy estuarine environments. For C0 ≤ 10.6%, strong clay winnowing efficiency under combined flows resulted in the formation of equilibrium clean-sand ripples and clay loss at depths far below the ripple base. In natural environments, this ‘deep cleaning’ of bed clay may cause a concurrent sudden release of a large amount of pollutants during storms, and lead to a sudden reduction in post-storm resistance to erosion of mixed sand–clay substrates.

scholarly journals Shifting baselines in coral conservation

2019 ◽  
Vol 3 (1) ◽  
pp. 20-39 ◽  
Author(s):  
Irus Braverman
Keyword(s):  
Coral Reefs ◽  
Reef Coral ◽  
Historical Records ◽  
Effective Management ◽  
Symbiotic Algae ◽  
Space And Time ◽  
Shifting Baselines ◽  
The Future ◽  
Restoration Practices ◽  
Management Policies

Reef-building corals are increasingly exposed to warming ocean temperatures. Their immediate response to this rise in temperature is to expel their symbiotic algae and turn white, or bleach. It is mainly for these reasons that corals have been perceived by scientists as both a sign and a measure of the imminent catastrophe facing life in the oceans and, subsequently, on earth. To measure coral decline across space and time, coral scientists have come up with maps, indexes, and color-coded representations. Yet they soon realized that what they regard as today’s healthy reef is, in fact, yesterday’s depleted reef. This problem, referred to as the shifting baselines syndrome, renders most comparisons across time difficult and frustrates the ability to predict the future. The problem is exacerbated in the context of oceans, and further yet in the context of coral reefs, because of the lack of reliable historical records. In fact, many of the coral scientists I have interviewed perceive shifting baselines as one of the key challenges facing coral conservation scientists and managers in their attempts to accurately calculate coral decline—a project that is typically deemed necessary for effective management policies and restoration practices. My article will critically explore the application of, and the assumptions behind, the shifting baselines concept in the context of reef coral science. Specifically, I will draw on interviews with coral scientists to describe the practices and devices embedded in the creation of baselines for corals and, finally, I will explore how certain scientists are challenging the conceptions of nature and time that underlie their operations.

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