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Identifying the spatial pattern and the drivers of the decline in the eastern English Channel chlorophyll-a surface concentration over the last two decades Full text
2024
Huguet, Antoine | Barillé, Laurent | Soudant, Dominique | Petitgas, Pierre | Gohin, Francis | Lefebvre, Alain
It has been established from previous studies that chlorophyll-a surface concentration has been declining in the eastern English Channel. This decline has been attributed to a decrease in nutrient concentrations in the rivers. However, the decrease in river discharge could also be a cause. In our study, rivers outflows and in-situ data have been compared to time series of satellite-derived chlorophyll-a concentrations. Dynamic Linear Model has been used to extract the dynamic and seasonally adjusted trends of several environmental variables. The results showed that, for the 1998–2019 period, chlorophyll-a levels stayed significantly lower than average and satellite images revealed a coast to offshore gradient. Chlorophyll-a concentration of coastal stations appeared to be related to the declining fluxes of phosphate while offshore stations were more related to nitrate-nitrite. Therefore, we can exclude that the climate variability, through river flows alone, has a dominant effect on the decline of chlorophyll-a concentration.
Show more [+] Less [-]Sediment grain size and benthic community structure in the eastern English Channel: Species-dependent responses and environmental influence Full text
2024
Chauvel, Nathan | Raoux, Aurore | Weill, Pierre | Dezilleau, Laurent | Méar, Yann | Murat, Anne | Poizot, Emmanuel | Foveau, Aurélie | Desroy, Nicolas | Thiébaut, Éric | Dauvin, Jean-claude | Pezy, Jean-philippe
This study addresses the scarcity of evidence on the relationship between benthic communities and coarse-grained sediments in the eastern English Channel. The region's geological history contributes to its predominantly coarse sediment composition. The study employs ternary plots to visualize benthic species' preferences and tolerance for sediment types, revealing their effectiveness. Redundancy Analyses (RDA) and species-level quantile regressions explore the influence of grain size on benthic species distribution. The results indicate a moderate impact of grain size, influenced by hydrodynamics. Estuaries, particularly the Seine Estuary, significantly shape benthic species distribution. Quantile regressions underscore the varied responses of benthic communities along the grain size gradient. The study underscores the importance of considering coarse sediments, offering insights into the complex relationship between benthic communities and sediment characteristics.
Show more [+] Less [-]Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene Full text
2024
Lee, Guan-hong | Jung, Nathalie | Dellapenna, Tim | Ra, Kongtae | Chang, Jongwi | Kong, Gee Soo | Nahm, Wook-hyun | Park, Buhm Soon | Jeong, Hyeryeong
Estuaries, vital coastal ecosystems, face growing threats from industrialization. To understand the pace of sedimentary changes and heavy metal pollution at the anthropogenically altered and industrialized Nakdong River Estuary in South Korea, we used sediment coring to reconstruct environmental change. Estuarine dam construction in 1934 shifted the sedimentary system from sand to mud, coinciding with a post-1930s mercury increase due to coal burning. Mercury concentrations in other South Korean regions surged in the 1970s, indicating proximity to emission sources matters. However, most heavy metal levels (Cu, Cd, Zn, Ag) sharply rose in the 1960s and 1970s with regional industrialization. Modern heavy metal concentrations doubled pre-industrial levels, underscoring human activities as the primary driver of Nakdong Estuary environmental changes. This emphasizes the need for a balanced approach to development and environmental preservation.
Show more [+] Less [-]Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island Full text
2024
Sababadichetty, Loik | Miltgen, Guillaume | Vincent, Bryan | Guilhaumon, François | Lenoble, Veronique | Thibault, Margot | Bureau, Sophie | Tortosa, Pablo | Bouvier, Thierry | Jourand, Philippe
Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island Full text
2024
Sababadichetty, Loik | Miltgen, Guillaume | Vincent, Bryan | Guilhaumon, François | Lenoble, Veronique | Thibault, Margot | Bureau, Sophie | Tortosa, Pablo | Bouvier, Thierry | Jourand, Philippe
The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 107 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.
Show more [+] Less [-]Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island Full text
2024
Sababadichetty, Loik | Miltgen, Guillaume | Vincent, Bryan | Guilhaumon, François | Lenoble, Véronique | Thibault, Margot | Bureau, Sophie | Tortosa, Pablo | Bouvier, Thierry | Jourand, Philippe | Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE [Réunion]) ; Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS) | Centre Hospitalier Universitaire de La Réunion (CHU La Réunion) | Processus Infectieux en Milieu Insulaire Tropical (PIMIT) ; Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-IRD-Centre National de la Recherche Scientifique (CNRS) | Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM) | Institut méditerranéen d'océanologie (MIO) ; Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) | The Ocean Cleanup | Interactions moléculaires et réactivité chimique et photochimique (IMRCP) ; Institut de Chimie de Toulouse (ICT) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT) ; Institut National des Sciences Appliquées - Toulouse (INSA Toulouse) ; Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse) ; Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) | Cyclotron Réunion Océan Indien (CYROI) ; Université de La Réunion (UR)-Centre Hospitalier Universitaire de La Réunion (CHU La Réunion) | MARine Biodiversity Exploitation and Conservation - MARBEC (UMR MARBEC) ; Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM) | This study was supported by funds from the Structure Federative de Recherche Biosecurite en milieu Tropical (BIOST), Universite de la Reunion (France) and Institut de Recherche pour le Developpement (IRD). Project ID: BMRPLAST.
NGS raw data 16SrDNA sequences are deposited in zenodo data bank: https://doi.org/10.5281/zenodo.8063253. | International audience | Highlights: • Severe marine plastic pollution impacts Southwest Indian Ocean insular ecosystems. • Plastic debris from Southwest Indian Ocean host rich microbiomes. • Proteobacteria dominate such marine plastic microbiomes. • These debris carry a consequent culturable bacterial flora including potential pathogens. • AMR bacteria hitchhike on these plastics.Abstract: The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km 2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 10 7 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.
Show more [+] Less [-]Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island Full text
2024
Sababadichetty, Loik | Miltgen, Guillaume | Vincent, Bryan | Guilhaumon, François | Lenoble, Véronique | Thibault, Margot | Bureau, Sophie | Tortosa, Pablo | Bouvier, Thierry | Jourand, Philippe
The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 107 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.
Show more [+] Less [-]Presenting a new model of municipal waste management cost reduction priorities based on the Gray-TOPSIS model Full text
2024
Seyed Rasoul Salehi | Reza Raoufi | Katayoon Varshosaz | Seyed Mohammad Mirhosseini | Reza Jalilzadeh Yengejeh
The role of economic factors is significant in the municipal waste management. The present descriptive-applied study aimed to present a new model of municipal waste management cost reduction priorities based on the Gray-TOPSIS model in Ahvaz City in 2022. Following the collection of data on the current municipal waste management, effective criteria influencing cost reduction in municipal waste management were determined through document analysis. Expert analysis was also utilized to identify factors impacting cost reduction in municipal waste management. The Gray-TOPSIS methodology was applied to prioritize solutions for cost reduction in municipal waste management. Through calculating the Kendall agreement index, 20 solutions for cost reduction in waste management were categorized and prioritized into educational, political, cultural, and executive groups. The findings revealed that while political measures such as approving laws related to municipal waste management and incentive and punitive policies with special weightings of 0.804 and 0.799, respectively, are the most effective solutions for reducing waste management costs, overall, educational process-related solutions with an average weighting of 0.686 have a higher priority than other processes. Government support and public education through various means, especially non-governmental media and social networks, are potential solutions for reducing municipal waste management costs in Ahvaz City under current conditions.
Show more [+] Less [-]Identifying and ranking indicators affecting the environment with the aim of providing a guide on the establishment and operation of exhibition sites using BWM multi-criteria decision making method Full text
2024
Davoud Adineh | Reza Amirnezhad | Keyvan Saeb | Aptin x Aptin Rahnavard | Farid Gholamreza Fahimi
The exhibition industry serves as a huge platform for face-to-face participation and the formation of potential economic and business relationships in the current century. These gatherings cost greatly in terms of energy resources are responsible for the emission of greenhouse gases and other pollutants into the water, air, and soil. The present study seeks to investigate and identify the pollutant indices resulting from the activities of the exhibition industry, its respective services and preparing guide on the organization of exhibition sites. For this purpose, the most important environmental criteria influenced by the industry were first identified through the Delphi method and were then classified into nine main priority groups based on multi-criteria decision-making and the best/ worst method(BWM[1]) method. The environmental index of the region was thus selected as the most important criterion whereas the social and economic indices were determined to be the least important criteria. Moreover, 58 sub-indices of the main indices were also weighed and prioritized based on the pairwise comparison. As a result, the sub-criterion of environmentally sensitive region ranked first while the sub-criterion of impact on the local and regional identity was identified as the least important influential sub-criterion. Weighing and prioritization of the indices were eventually the main foundation for the compilation of the exhibition site construction and operation instructions, and persistent monitoring of some indices such as the indoor air quality and consumed energy can reduce the negative environmental consequences of exhibition activities significantly.
Show more [+] Less [-]Antibacterial effects of copper- and silver-coated carbon nanotubes synthesized by plasma-enhanced chemical vapor deposition on Staphylococcus aureus and Escherichia coli: a comparative study Full text
2024
Pooya Sepehr | Seyed Majid Borghei | Morad Ebrahimkhas | Nasim Nobari
The use of copper (Cu) and silver (Ag) nanoparticles in coatings can eliminate surface microbial contamination. This study compared antibacterial activity of Cu- (Cu/CNTs) and Ag-coated carbon nanotubes (Ag/CNTs) synthesized by plasma-enhanced chemical vapor deposition (PECVD) against Escherichia coli and Staphylococcus aureus. Initially, the PECVD technique was applied to deposit the CNTs on high-resistivity silicon wafers previously decorated by nickel catalyst using an Electron Beam Gun. Then, the nanotubes were coated by Cu and Ag thin films in a vacuum evaporator using the Direct Current (DC) Magnetron Sputtering method. Finally, the antibacterial effects were determined by Standard Plate Count (SPC, with film thicknesses of 0, 10, 30 and 60 nm) and Disk Diffusion Test (based on zone of inhibition (ZOI) with nanoparticle concentrations of 5, 10 and 15 µg/mL). According to the SPC findings, the highest antibacterial activity of Cu/CNTs was found for the film thickness of 60 nm against E. coli (66%), and the lowest activity was related to the film thickness of 19 nm against S. aureus (28.8%). The antibacterial activity of Ag/CNTs was about 70% against E. coli with the highest thickness and about 34.12% against S. aureus. The lowest ZOI was measured for the bare CNTs at a concentration of 5 µg/mL (12 mm), and the highest ZOI was related to Ag/CNTs with a concentration of 15 µg/mL against S. aureus (18 mm). To conclude, the carbon nanotube composites coated with copper or silver nanoparticles can be used to control bacterial growth in aqueous solutions.
Show more [+] Less [-]Scenario-based land use management to restore natural areas and reducing soil erosion rate in a competing land uses condition Full text
2024
Khadijeh Haji | Abazar Esmali-Ouri | Raoof Mostafazadeh | Habib Nazarnejad
Identifying the contribution of different land uses plays a crucial role in preventing erosion and prioritizing land management activities. This research aimed to assess the impacts of various land use scenarios on mitigating soil erosion in the North West Urmia region of Iran. In addition to the current scenario, 12 land use management scenarios were identified based on the observed trend in changes in land use patterns throughout the study area utilizing GIS. The RUSLE was used, and the necessary input parameters of the RUSLE model, were prepared. The erosion mapping has been done using overlaying the input layers. The baseline scenario (current condition) resulted in an erosion amount of 17.22 (t/ha/yr). Introducing soil conservation techniques in dry farming on steep terrain, as depicted in scenario 6 (conservation and restoration of plowed rangelands), resulted in a reduction of the erosion rate from 17.22 to 9.75 (t/ha/yr). On the other hand, scenario 20, characterized by severe rangeland degradation and overgrazing, exhibited the highest estimated erosion rate at 30.42 (t/ha/yr). In contrast, the most substantial erosion reduction of 43.37% was evident in scenario 6 (conservation and restoration of plowed rangelands). It was observed that the P-factor (support practice factor) had a more pronounced impact than the C-factor (crop/vegetation and management factor) in mitigating erosion. These findings suggest the potential for utilizing a scenario-based framework to evaluate the impact of management scenarios on erosion and prioritize soil and water management measures and strategies.
Show more [+] Less [-]Prediction of Ground-Level Air Pollution Using Artificial Neural Network in Tehran Full text
2024
Afshin Khoshand | Mahshid Shahbazi Sehrani | Hamidreza Kamalan | Siamak Bodaghpour
Novel technologies and subsequent pollutions are serious threats to the environment and public health. The environmental pollutions, especially air pollution, are currently leading environmental concerns in developing countries, including Iran. In the present study, the air quality and meteorological data were employed to achieve potent models based on an Artificial Neural Network (ANN) for the prediction of air pollution in Tehran, Iran. The developed models manage to predict daily concentrations of various air pollutants such as O3, PM10, NO2, CO, and PM2.5. The required data were collected daily through the Air Quality Organization from all air quality stations of Tehran within a four-year period (from 2012 to 2015). Training the models was on the basis of Multi-Layer Perceptron (MLP) with the Back Propagation (BP) algorithm using MATLAB program. The results indicated appropriate agreement between the observed and predicted concentrations, as the values of the coefficient of multiple determinations (R2) for all models were more than 0.83. In conclusion, the studied meteorological parameters are effective on all pollutants concentrations.
Show more [+] Less [-]Investigating multiple human pressure types in the southern Caspian Sea Basin Rivers at different spatial scales toward Integrating Water Resource Management (IWRM) in Iran Full text
2024
Hossein Mostafavi | Azad Teimori
Water security problems are becoming more and more challenging in Iran for several reasons such as population growth, urbanization, land-use change, unsustainable water use and climate change. All the mentioned reasons result in an increase in the human exploitation of water resources and consequently increasing anthropogenic impacts on rivers, flood plains, and fresh groundwater. Therefore, assessment of the human pressures on rivers is particularly important to find areas where water resources are threatened and subjected to rapidly increasing anthropogenic effects. By this integrated approach, a successful Integrated Water Resources Management will be achieved to guide policy makers for best protection, restoration and management. In this regard, Southern Caspian Sea Basin Rivers (including Kura-South Caspian and Caspian Highland ecoregions) were studied in terms of human pressure types. Human pressures were analyzed at different spatial scales, and finally seven main pressure types (i.e. Land use, Hydrology, Morphology, Connectivity, Water quality, Biology) were defined in which the abundance and distributions of each pressure type was different. According to this study, most areas were impacted by land use pressure type followed by water quality. Moreover, most areas were threatened by multiple pressures.
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