خيارات البحث
النتائج 171 - 180 من 680
The French Mussel Watch Program reveals the attenuation of coastal lead contamination over four decades النص الكامل
2024
Barreira, João | Ferreira Araujo, Daniel | Knoery, Joël | Briant, Nicolas | Machado, Wilson | Grouhel, Anne
The mid-20th century industrial peak caused severe global lead (Pb) marine contamination. Although Europe initiated Pb emission reduction regulations in the 1980s, the short- and long-term impacts remain unclear. This study investigates the evolution of Pb contamination on the French coast through elemental and isotope analysis in oysters and mussels from the French “Mussel Watch” Program. Observations at 114 monitoring stations over four decades have shown decreasing Pb levels in these bivalve mollusks. In 1988, 95 % exceeded the background reference values; this level had dropped to 39 % by 2021. The Pb isotope ratios in bivalves from eight target sites revealed a reduction in bioaccumulated anthropogenic Pb, albeit without complete elimination. The long residence time of legacy Pb combined with inputs from diffuse urban sources likely explains the persistent presence of anthropogenic Pb on the French coast. This study endorses the importance of continuous biomonitoring to evaluate environmental regulations and policies.
اظهر المزيد [+] اقل [-]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 النص الكامل
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.
اظهر المزيد [+] اقل [-]Identifying the spatial pattern and the drivers of the decline in the eastern English Channel chlorophyll-a surface concentration over the last two decades النص الكامل
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.
اظهر المزيد [+] اقل [-]Sediment grain size and benthic community structure in the eastern English Channel: Species-dependent responses and environmental influence النص الكامل
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.
اظهر المزيد [+] اقل [-]Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene النص الكامل
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.
اظهر المزيد [+] اقل [-]Organophosphate ester additives and microplastics in benthic compartments from the Loire estuary (French Atlantic coast) النص الكامل
2024
Castro-jiménez, Javier | Aminot, Yann | Bely, Nadege | Pollono, Charles | Idjaton, B.i.t. | Bizzozero, Lucie | Pierre-duplessix, Olivier | Phuong, N.n. | Gasperi, J.
We report the first empirical confirmation of the co-occurrence of organophosphate esters (OPEs) additives and microplastics (MPs) in benthic compartments from the Loire estuary. Higher median concentrations of MPs (3387 items/kg dw), ∑13tri-OPEs (12.0 ng/g dw) and ∑4di-OPEs (0.7 ng/g dw) were measured in intertidal sediments with predominance of fine particles, and under higher anthropogenic pressures, with a general lack of seasonality. Contrarily, Scrobicularia plana showed up to 4-fold higher ∑tri-OPE concentrations in summer (reaching 37.0 ng/g dw), and similar spatial distribution. Polyethylene predominated in both compartments. Tris(2-ethylhexyl) phosphate (TEHP), its degradation metabolite (BEHP) and tris-(2-chloro, 1-methylethyl) phosphate (TCIPP) were the most abundant OPEs in sediments, while TCIPP predominated in S. plana. The biota-sediment accumulation factors suggest bioaccumulation potential for chlorinated-OPEs, with higher exposure in summer. No significant correlations were generally found between OPEs and MPs in sediments suggesting a limited role of MPs as in-situ source of OPEs.
اظهر المزيد [+] اقل [-]Metal record of copper-based antifouling paints in sediment core following marina construction and operation النص الكامل
2024
Cunha, Bruno | Garnier, Jeremie | Ferreira Araujo, Daniel | Tonhá, Myller | Souto-oliveira, Carlos Eduardo | Ruiz, Izabel | Feitas E Silva, Flavio Henrique | Almeida, Tati | Freydier, Remi | Seyler, Patrick | Babinski, Marly
Marinas are central hubs of global maritime leisure and transport, yet their operations can deteriorate the environmental quality of sediments. In response, this study investigated the metal contamination history associated with antifouling paint uses in a sediment core collected from Bracuhy marina (Southeast Brazil). Analysis target major and trace elements (Cu, Zn, Pb, Cd and Sn), rare earth elements (REEs), and Pb isotopes. The modification in Pb isotopic ratios and REEs pattern unequivocally revealed sediment provenance disruption following the marina construction. Metal distribution in the sediment core demonstrates that concentrations of Cu and Zn increased by up to 15 and 5 times, respectively, compared to the local background. This severe Cu and Zn contamination coincides with the onset of marina operations and can be attributed to the use of antifouling paints.
اظهر المزيد [+] اقل [-]Persistent organic pollutants and trace metals in selected marine organisms from the Akanda National Park, Gabon (Central Africa) النص الكامل
2024
Sardenne, Fany | Le Loch, Francois | Bodin, Nathalie | Mve-beh, Jean-hervé | Munaron, Jean-marie | Mbega, Jean-daniel | Nzigou, Aime Roger | Sadio, Oumar | Budzinski, Hélène | Leboulanger, Christophe
Akanda National Park (ANP) is composed of mangrove ecosystems bordering Libreville, Gabon's capital. The contamination of aquatic resources from the ANP by persistent organic pollutants (POPs) and trace metals (TMs) was never evaluated. To provide a basis for their monitoring in the ANP, five species (two fish, two mollusks, and one crustacean) were analyzed from three sampling sites in 2017. Contamination levels for POPs and TMs were below maximum acceptable limits for seafood, including Cd and Pb. No DDT was found in any sample. Inter-specific differences were more obvious than the differences among sites, although the results may be biased by an unbalanced sampling design. The oyster Crassostrea gasar was the most contaminated species, making this species a good candidate to assess environmental contamination in the area. The studied species also contained essential elements, such as Fe, Zn and Mn at interesting levels in a nutritional point of view.
اظهر المزيد [+] اقل [-]Active mussel biomonitoring for the health status assessment of the Western Mediterranean Sea النص الكامل
2024
Benito, Denis | Briand, Marine | Herlory, Olivier | Izagirre, Urtzi | Bouchoucha, Marc | Briaudeau, Tifanie
The Western Mediterranean coast is under the influence of anthropogenic pressures, including land use, increasing amounts of dangerous waste and habitat destruction. In 2021, the French RINBIO network (http://www.ifremer.fr/envlit/) originally dedicated to assess chemical contamination in the region, focused on biological effects produced by contaminants and the interaction with natural variability in mussels using an active caging strategy. Cell and tissue level biomarkers were applied for 17 sampling sites divided in three sub-regions categorized by different environmental conditions. Results provide critical information for ecosystem health assessment using mussels as sentinel species in the Western Mediterranean Sea. The influence of natural and confounding factors (trophic condition, reproductive cycle, caging strategy), on biological responses to mild chemical contamination, was discussed and discriminated for health status assessment. Results provide valuable data available as reference values for the assessment of biomarkers and histopathological alterations for large-scale active biomonitoring campaigns in the Western Mediterranean Sea.
اظهر المزيد [+] اقل [-]Mismanaged plastic waste and the environmental Kuznets curve: A quantile regression analysis النص الكامل
2024
Rom, Punloeuvivorth | Guillotreau, Patrice
The relationship between economic growth, governance, and environmental outcomes, particularly mismanaged plastic waste (MPW) leaking out to the ocean, has been a focal point of policy and academic debates. This study aims to understand the dynamics of income and control of corruption across different levels of MPW. Utilizing Quantile Regression models, we explore the generalized and quantile-specific relationships between the variables. The findings confirm the validity of the Environmental Kuznets Curve (EKC), revealing an initial increase in MPW with economic growth, followed by a decline after surpassing a specific economic threshold. However, the EKC is not validated for all quantiles and the shifting point may vary across the distribution. Moreover, control of corruption emerged as a significant factor in determining MPW levels, emphasizing its moderating role at the highest levels of mismanagement. This study underscores the need for synergizing economic strategies with robust environmental policies, guided by strong governance mechanisms.
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