خيارات البحث
النتائج 1 - 10 من 35
Stress response to trace elements mixture of different embryo-larval stages of Paracentrotus lividus
2022
El Idrissi, Ouafa | Santini, J. | Bonnin, M. | Demolliens, M. | Aiello, A. | Gobert, Sylvie | Pasqualini, V. | Ternengo, S.
peer reviewed | This study investigated for the first time the oxidative biomarkers responses in all larval stages of sea urchin. The contamination effects were reproduced by using contaminated seawater to concentrations measured in the area adjacent to an old asbestos mine at factors of 5 and 10. The results suggested that the concentrations were not sufficiently high to induce a major oxidative stress. The biometric differences make this method a more sensitive approach for assessing the effects on sea urchin larvae. Measurements of specific activities of antioxidant enzymes at each stage suggested a high capacity of the larvae to respond to oxidative stress. This normal activity of the organism must be considered in future research. This work also highlighted the importance of spawners provenance in ecotoxicological studies. These data are essential to better understand the stress responses of sea urchin larvae and provide baseline information for later environmental assessment research.
اظهر المزيد [+] اقل [-]Active and passive biomonitoring of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in small Mediterranean harbours
2023
Castrec, Justine | Pillet, Marion | Receveur, Justine | Fontaine, Quentin | Le Floch, Stéphane | Churlaud, Carine | Lejeune, Pierre | Gobert, Sylvie | Thomas, Hélène | Marengo, Michel
peer reviewed | Quality of the marine environment in the Mediterranean port areas (QUAMPO) | Pollution particularly affects coastal ecosystems due to their proximity to anthropic sources. Among those en- vironments, harbours are subjected to marine traffic but also to accidental and chronic pollution. These areas are thus exposed to complex mixtures of contaminants such as trace elements and organic contaminants which can impact marine species, habitats, and ecosystem services. The monitoring of these compounds is thus a crucial issue for assessment of environmental health. In this context, the aim of the present work was to evaluate the chemical contamination of harbours in Corsica (NW Mediterranean) by measuring the bioaccumulation of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in mussels, limpets, and sea cu- cumbers. The human health risks associated with seafood consumption were also assessed. Results reveal a relatively low contamination in the Corsican harbours studied compared to larger Mediterranean ports and suggest that the potential health risk for consumers eating seafood is low.
اظهر المزيد [+] اقل [-]Partial recovery of macrozoobenthos on the northwestern shelf of the Black Sea.
2024
Chevalier, Séverine | Beauchard, Olivier | Teacă, Adrian | Soetaert, Karline | Grégoire, Marilaure
peer reviewed | The northwestern shelf of the Black Sea has been affected by eutrophication and bottom hypoxia since the sixties. Consequently, the macrozoobenthos has suffered a well-established decline in biodiversity. However, the nature of the current benthic communities remains questionable. From 1995 to 2017, we compiled species and abiotic data for 138 sites over the shelf. Through an appropriate multivariate analytical approach, we identified benthic community changes solely due to organic pollution variations. Our results show signs of recovery with an increase in biodiversity and proportion of species vulnerable to organic enrichment. These changes were related to a decrease in riverine loads and subsequent eutrophication. However, some long-lived species typical of the area still did not exhibit noticeable recovery, which suggests that either the recovery process has not yet been achieved or some environmental conditions are still not met to warrant a sea floor ecosystem state substantially healthy. | 14. Life below water
اظهر المزيد [+] اقل [-]Trace elements in migratory species arriving to Antarctica according to their migration range
2023
Padilha, J A | Carvalho, G O | Espejo, W | Pessôa, A R L | Cunha, L S T | Costa, E S | Torres, J P M | Lepoint, Gilles | Das, Krishna | Dorneles, Paulo Renato
peer reviewed | The levels of eighteen trace elements (TEs) were evaluated in association with stable isotopes (δ15N, δ34S, and δ13C) in feathers and eggs of five migratory species breeding on the Antarctic Peninsula to test the factors that influence their exposure to contaminants. The feathers of seabirds migrating to the Northern Hemisphere (South polar skua) have concentrations (mean ± SD, μg. g-1) of Li (1.71 ± 2.08) and Mg (1169.5 ± 366.8) one order of magnitude higher than southern migrants, such as Snowy sheathbill Li (0.01 ± 0.005) and Mg (499.6 ± 111.9). Feathers had significantly higher concentrations for 11 of a total of 18 metals measured compared to eggs. South polar skua have higher concentrations of all TEs in eggs compared to antarctic tern. Therefore, the present study showed that migration and trophic ecology (δ15N, δ13C, and δ34S) influence Fe, Mn, Cu, and Se concentrations in feathers of Antarctic seabirds. The concentrations of Cu, Mn, Rb, Zn, Pb, Cd, Cr are higher than previously reported, which may be due to increased local and global human activities.
اظهر المزيد [+] اقل [-]Partial recovery of macrozoobenthos on the northwestern shelf of the Black Sea.
2024
Chevalier, Séverine | Beauchard, Olivier | Teacă, Adrian | Soetaert, Karline | Grégoire, Marilaure
peer reviewed | The northwestern shelf of the Black Sea has been affected by eutrophication and bottom hypoxia since the sixties. Consequently, the macrozoobenthos has suffered a well-established decline in biodiversity. However, the nature of the current benthic communities remains questionable. From 1995 to 2017, we compiled species and abiotic data for 138 sites over the shelf. Through an appropriate multivariate analytical approach, we identified benthic community changes solely due to organic pollution variations. Our results show signs of recovery with an increase in biodiversity and proportion of species vulnerable to organic enrichment. These changes were related to a decrease in riverine loads and subsequent eutrophication. However, some long-lived species typical of the area still did not exhibit noticeable recovery, which suggests that either the recovery process has not yet been achieved or some environmental conditions are still not met to warrant a sea floor ecosystem state substantially healthy. | 14. Life below water
اظهر المزيد [+] اقل [-]Production and sedimentation of peptide toxins nodularin-R and microcystin-LR in the northern Baltic Sea
2009
Kankaanpää, Harri T. | Sjövall, Olli | Huttunen, Maija | Olin, Miikka | Karlsson, Krister | Hyvärinen, Kirsi | Sneitz, Laura | Härkönen, Janne | Sipiä, Vesa O. | Meriluoto, Jussi A.O.
This seven-year survey was primarily targeted to quantification of production of nodularin-R (NOD-R), a cyclic pentapeptide hepatotoxin, in Baltic Sea cyanobacteria waterblooms. Additionally, NOD-R and microcystin-LR (MC-LR; a cyclic heptapeptide toxin) sedimentation rates and NOD-R sediment storage were estimated. NOD-R production (70-2450 μg m⁻³; 1 kg km⁻² per season) and sedimentation rates (particles; 0.03-5.7 μg m⁻² d⁻¹; 0.3 kg km⁻² per season) were highly variable over space and time. Cell numbers of Nodularia spumigena did not correlate with NOD-R quantities. Dissolved NOD-R comprised 57-100% of total NOD-R in the predominantly senescent, low-intensity phytoplankton blooms and seston. Unprecedentedly intensive MC-LR sedimentation (0.56 μg m⁻² d⁻¹) occurred in 2004. Hepatotoxin sedimentation rates highly exceeded those of anthropogenic xenobiotics. NOD-R storage in surficial sediments was 0.4-20 μg kg⁻¹ (0.1 kg km⁻²). Loss of NOD-R within the chain consisting of phytoplankton, seston and soft sediments seemed very effective. Production of nodularin-R in pelagic Baltic Sea takes place in a scale of up to kilograms per square kilometre.
اظهر المزيد [+] اقل [-]An assessment of metal contamination along the Irish coast using the seaweed Ascophyllum nodosum (Fucales, Phaeophyceae)
2008
Morrison, L. | Baumann, H.A. | Stengel, D.B.
The relative abundance and variation of Cr, Co, Cd and Pb in Ascophyllum nodosum and intertidal surface sediments from six locations around the coast were assessed over six seasons. Higher Cd and Pb levels in Galway Docks and Cork Harbour were attributed to localised inputs of these metals from municipal and domestic waste, while at a reference site (Ballyconneely), high algal Cr concentrations were considered a function of geological setting rather than anthropogenic loading. Little seasonal variation was observed, with the exception of higher Co levels in plants in winter, associated with growth dynamics and increased fluvial inputs. In comparison with previously published data for metals in A. nodosum from the North Atlantic, with the exception of localised hot spots, the Irish coastline is still a relatively pristine environment. A. nodosum may be successfully and easily used as a biomonitor of metal contamination in coastal waters. This paper provides details of an easily applicable, cost-effective and ecologically relevant approach to assessing the degree of metal contamination in coastal environments.
اظهر المزيد [+] اقل [-]Modelling of oil spills in confined maritime basins: The case for early response in the Eastern Mediterranean Sea
2015
Alves, Tiago M. | Kokinou, Eleni | Zodiatis, George | Lardner, Robin | Panagiotakis, Costas | Radhakrishnan, Hari
Oil spill models are combined with bathymetric, meteorological, oceanographic, and geomorphological data to model a series of oil spill accidents in the Eastern Mediterranean Sea. A total of 104 oil spill simulations, computed for 11 different locations in the Levantine Basin, show that oil slicks will reach the coast of Cyprus in four (4) to seven (7) days in summer conditions. Oil slick trajectories are controlled by prevailing winds and current eddies. Based on these results, we support the use of chemical dispersants in the very few hours after large accidental oil spills. As a corollary, we show shoreline susceptibility to vary depending on: a) differences in coastline morphology and exposure to wave action, b) the existence of uplifted wave-cut platforms, coastal lagoons and pools, and c) the presence of tourist and protected environmental areas. Mitigation work should take into account the relatively high susceptibility of parts of the Eastern Mediterranean.
اظهر المزيد [+] اقل [-]Tidal influence on the distribution of hydrophobic organic contaminants in the Seine Estuary and biomarker responses on the copepod Eurytemora affinis
2009
Cailleaud, K. | Forget-Leray, J. | Peluhet, L. | LeMenach, K. | Souissi, S. | Budzinski, H.
To elucidate tidally related variations of hydrophobic organic contaminant (HOC) bioavailability and the impact of these contaminants on estuarine ecosystems, both PCB and PAH concentrations were investigated in the dissolved phase and in the suspended particulate material (SPM) of the Seine Estuary. Both PAH and PCB highest levels were observed in surface and bottom water when SPM remobilizations were maximum, in relation to higher speed currents. In parallel, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities were investigated in the copepod Eurytemora affinis. Significant decreasing AChE levels were measured during the tidal cycle and between surface and bottom copepods related to salinity and to HOC concentration variations. Significant increasing GST levels were also observed when HOC concentrations in the water column were the highest. This study underlined the need to standardize sampling procedures for biomonitoring studies in order to avoid interfering factors that could modify biomarker responses to chemical exposure. Variations of contamination of E. affinis and enzymatic responses have been studied over a tide cycle in view to improve the use of this copepod for biomonitoring.
اظهر المزيد [+] اقل [-]The application of a weight of evidence approach to compare the quality of coastal sediments affected by acute (Prestige 2002) and chronic (Bay of Algeciras) oil spills
2008
Morales-Caselles, Carmen | Riba, Inmaculada | Sarasquete, Carmen | DelValls, T Ángel
To evaluate sediment quality in different areas affected by oil spills, a weight of evidence approach was employed by including a complete set of parameters as part of four lines of evidence: sediment contamination, biological effects (including biomarkers) and bioaccumulation under laboratory conditions, toxicity in field conditions and benthic community structure. The methodology was applied to sediments from the Bay of Algeciras (S Spain) chronically impacted by different spills, and the Galician Coast (NW Spain) acutely impacted by an oil spill (Prestige 2002). Results obtained have elucidated the sources and fates of pollutants and the type of risk involved for the ecosystem. Factorial analysis revealed that the main factors were those containing toxicity, chemistry and benthic community variables indicating degradation in Algeciras. It has been demonstrated that the impact associated with chronic event of contamination by oil spills are significantly more dangerous and polluted than those related to acute effects. Chronic inputs due to the continuous entrance of contaminants result in much more harm to coastal ecosystems than major but precise environmental impacts.
اظهر المزيد [+] اقل [-]