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النتائج 31 - 40 من 302
Phthalates and organophosphate esters in surface water, sediments and zooplankton of the NW Mediterranean Sea: exploring links with microplastic abundance and accumulation in the marine food web
2021
Schmidt, Natascha | Castro-jiménez, Javier | Oursel, Benjamin | Sempéré, Richard
In this study, surface seawater, sediment and zooplankton samples were collected from three different sampling stations in Marseille Bay (NW Mediterranean Sea) and were analyzed for both microplastics and organic plastic additives including seven phthalates (PAEs) and nine organophosphate esters (OPEs). PAE concentrations ranged from 100 to 527 ng L-1 (mean 191±123 ng L-1) in seawater, 12 to 610 ng g-1 dw (mean 194±193 ng g-1 dw) in sediment and 0.9 to 47 μg g-1 dw (mean 7.2±10 μg g-1 dw) in zooplankton, whereas OPE concentrations varied between 9-1013 ng L-1 (mean 243±327 ng L-1) in seawater, 13-49 ng g-1 dw (mean 25±11 ng g-1 dw) in sediment and 0.4-4.6 μg g-1 dw (mean 1.6±1.0 μg g-1 dw) in zooplankton. Microplastic counts in seawater ranged from 0 to 0.3 items m-3 (mean 0.05±0.05 items m-3). We observed high fluctuations in contaminant concentrations in zooplankton between different sampling events. However, the smallest zooplankton size class generally exhibited the highest PAE and OPE concentrations. Field-derived bioconcentration factors (BCFs) showed that certain compounds are prone to bioaccumulate in zooplankton, including some of the most widely used chlorinated OPEs, but with different intensity depending on the zooplankton size-class. The concentration of plastic additives in surface waters and the abundance of microplastic particles were not correlated, implying that they are not necessarily good indicators for each other in this compartment. This is the first comprehensive study on the occurrence and temporal variability of PAEs and OPEs in the coastal Mediterranean based on the parallel collection of water, sediment and differently sized zooplankton samples.
اظهر المزيد [+] اقل [-]Nanoplastics exposure modulate lipid and pigment compositions in diatoms
2020
Gonzalez-fernandez, Carmen | Le Grand, Fabienne | Bideau, Antoine | Huvet, Arnaud | Paul-pont, Ika | Soudant, Philippe
The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS–NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 μg mL−1) and a high (5 μg mL−1) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom’ cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.
اظهر المزيد [+] اقل [-]Tools and constraints in monitoring interactions between marine litter and megafauna: Insights from case studies around the world
2019
Claro, F | Fossi, Mc | Ioakeimidis, C | Baini, M | Lusher, Al | Mc Fee, W | Mcintosh, Rr | Pelmatti, T | Sorce, M | Galgani, Francois | Hardesky, Bd
Adverse impacts of marine litter is documented on >1400 species, including marine megafauna (fish, birds, sea turtles and mammals). The primary impacts include ingestion and entanglement, and there is increasing concern about chemical contamination via ingestion. Numerous survey approaches and monitoring programs have been developed and implemented around the world. They may aim to provide data about parameters such as species distribution and interactions with anthropogenic activities. During the Sixth International Marine Debris Conference, a session was dedicated to the tools and constraints in monitoring interactions between litter and megafauna. In the present paper, we summarize 7 case studies which discuss entanglement and ingestion including macro- and micro-debris in several taxa and across multiple geographic regions. We then discusses the importance of tools and standardizing methods for assessment and management purposes, in the context of international environmental policies and marine litter strategies.
اظهر المزيد [+] اقل [-]Impact of chronic cadmium exposure at environmental dose on escape behaviour in sea bass (Dicentrarchus labrax L.; Teleostei, Moronidae)
2008
Faucher, Karine | Fichet, Denis | Miramand, Pierre | Lagardere, Jean-paul
The effect of chronic exposure to a low concentration (0.5 mu g l(-1)) of cadmium ions was investigated on escape behaviour of sea bass, Dicentrarchus labrax, using video analysis. Observations were also performed on the microanatomy of lateral system neuromasts. When fish were exposed for 4 h per day over 8 days to the cadmium ions, most of both types of neuromasts observed remained intact. However, some of them presented damaged sensory maculae. Whereas before cadmium exposure, fish responded positively to nearly all the lateral system stimulations, after exposure they decreased by about 10% their positive responses to Stimulations. From the 15th day after the beginning of cadmium exposure, neuromasts presented progressively less damage, cadmium accumulation in gills and scales decreased significantly and fish escape behaviour had recovered. This study presents a new concept in ecotoxicology: using behavioural change to reveal the effects of pollution levels, scarcely detectable by currently used techniques (physiological responses). (C) 2007 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Metal record of copper-based antifouling paints in sediment core following marina construction and operation
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 [-]Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene
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 [-]Identifying the spatial pattern and the drivers of the decline in the eastern English Channel chlorophyll-a surface concentration over the last two decades
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 [-]Active mussel biomonitoring for the health status assessment of the Western Mediterranean Sea
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 [-]Occurrence and distribution of PAHs in stranded dolphin tissues from the Northwestern Mediterranean
2023
Dron, Julien | Wafo, Emmanuel | Boissery, Pierre | Dhermain, Frank | Bouchoucha, Marc | Chamaret, Philippe | Lafitte, Daniel
There are few cetacean tissue-specific polycyclic aromatic hydrocarbon (PAH) concentration studies in the Mediterranean, despite this region is among the most subjected to chemical contamination. PAH analyses were conducted in different tissues of striped dolphins (Stenella coeruleoalba, N = 64) and bottlenose dolphins (Tursiops truncatus, N = 9) stranded along the French Mediterranean coastline from 2010 to 2016. Comparable levels were measured in S. coeruleoalba and T. trucantus (1020 and 981 ng g−1 lipid weight in blubber, 228 and 238 ng g−1 dry weight in muscle, respectively). The results suggested a slight effect of maternal transfer. The greatest levels were recorded by urban and industrial centers, and decreasing temporal trends were observed in males muscle and kidney, but not in other tissues. As a conclusion, the elevated levels measured could represent a serious threat to dolphins populations in this region, particularly by urban and industrial centers.
اظهر المزيد [+] اقل [-]Sponge organic matter recycling: Reduced detritus production under extreme environmental conditions
2023
Maggioni, Federica | Bell, James J. | Pujo-pay, Mireille | Shaffer, Megan | Cerrano, Carlo | Lemonnier, Hugues | Letourneur, Yves | Rodolfo-metalpa, Riccardo
Sponges are a key component of coral reef ecosystems and play an important role in carbon and nutrient cycles. Many sponges are known to consume dissolved organic carbon and transform this into detritus, which moves through detrital food chains and eventually to higher trophic levels via what is known as the sponge loop. Despite the importance of this loop, little is known about how these cycles will be impacted by future environmental conditions. During two years (2018 and 2020), we measured the organic carbon, nutrient recycling, and photosynthetic activity of the massive HMA, photosymbiotic sponge Rhabdastrella globostellata at the natural laboratory of Bouraké in New Caledonia, where the physical and chemical composition of seawater regularly change according to the tide. We found that while sponges experienced acidification and low dissolved oxygen at low tide in both sampling years, a change in organic carbon recycling whereby sponges stopped producing detritus (i.e., the sponge loop) was only found when sponges also experienced higher temperature in 2020. Our findings provide new insights into how important trophic pathways may be affected by changing ocean conditions.
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