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Capability of Paraguaçu estuary (Todos os Santos Bay, Brazil) to form oil–SPM aggregates (OSA) and their ecotoxicological effects on pelagic and benthic organisms Texto completo
2017
For experiments concerning the formation of oil–suspended particulate matter (SPM) aggregates (OSA), oil and sediment samples were collected from Campos Basin and six stations of Paraguaçu estuary, Todos os Santos Bay, Brazil, respectively. The sediments samples were analyzed for organic matter determined by the EMBRAPA method, nitrogen determined by the Kjeldahl method, and phosphorus determined by the method described by Aspila. The oil trapped in OSA was extracted following the method described by Moreira. The experiment showed a relationship between the amount of organic matter and OSA formation and consequently the dispersion of the studied oil. On the basis of the buoyancy of OSA and the ecotoxicological effects on pelagic and benthic community, the priority areas for application of remediation techniques are Cachoeira, Maragogipe, and Salinas da Margarida because of the large amount of oil that accumulated at the bottom of the experiment flask (5.85%, 27.95%, and 38,98%; 4.2%, 17.66%, and 32.64%; and 11.82%, 8.07%, and 10.91% respectively).
Mostrar más [+] Menos [-]Anthropogenic debris in the nests of kelp gulls in South Africa Texto completo
2017
Anthropogenic debris results in detrimental interactions with many marine species. Several seabirds include debris items in their nests, which can lead to entanglement of chicks and adults, resulting in injury or death. Anthropogenic debris was found in 4–67% of kelp gull Larus dominicanus nests in seven colonies in the Western Cape, South Africa. Nests contained two types of litter: items included in the nest structure during construction (mainly ropes and straps), and regurgitated items (mainly bags and food wrappers) that probably accumulate primarily during the chick-rearing period. Debris used in nest construction was more likely to injure gulls, and was found mainly at coastal sites where there was little natural vegetation for construction. Distance to the nearest urban waste landfill significantly affected the occurrence of debris items in nests, especially dietary-derived items. The amount of debris in kelp gull nests highlights the need for improved debris management in South Africa.
Mostrar más [+] Menos [-]The effects of oil spills on marine fish: Implications of spatial variation in natural mortality Texto completo
2017
Langangen, Ø | Olsen, E. | Stige, L.C. | Ohlberger, J. | Yaragina, N.A. | Vikebø, F.B. | Bogstad, B. | Stenseth, N.C. | Hjermann, D.Ø
The effects of oil spills on marine fish: Implications of spatial variation in natural mortality Texto completo
2017
Langangen, Ø | Olsen, E. | Stige, L.C. | Ohlberger, J. | Yaragina, N.A. | Vikebø, F.B. | Bogstad, B. | Stenseth, N.C. | Hjermann, D.Ø
The effects of oil spills on marine biological systems are of great concern, especially in regions with high biological production of harvested resources such as in the Northeastern Atlantic. The scientific studies of the impact of oil spills on fish stocks tend to ignore that spatial patterns of natural mortality may influence the magnitude of the impact over time. Here, we first illustrate how spatial variation in natural mortality may affect the population impact by considering a thought experiment. Second, we consider an empirically based example of Northeast Arctic cod to extend the concept to a realistic setting. Finally, we present a scenario-based investigation of how the degree of spatial variation in natural mortality affects the impact over a gradient of oil spill sizes. Including the effects of spatial variations in natural mortality tends to widen the impact distribution, hence increasing the probability of both high and low impact events.
Mostrar más [+] Menos [-]The effects of oil spills on marine fish: Implications of spatial variation in natural mortality Texto completo
2017
Langangen, Øystein | Olsen, Erik Joel Steinar | Stige, Leif Christian | Ohlberger, Jan Philipp | Yaragina, Natalia A. | Vikebø, Frode Bendiksen | Bogstad, Bjarte | Stenseth, Nils Christian | Hjermann, Dag Øystein
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Mostrar más [+] Menos [-]The effects of oil spills on marine fish: Implications of spatial variation in natural mortality Texto completo
2017
Langangen, Øystein | Olsen, Erik Joel Steinar | Stige, Leif Christian | Ohlberger, Jan Philipp | Yaragina, Natalia A. | Vikebø, Frode Bendiksen | Bogstad, Bjarte | Stenseth, Nils Christian | Hjermann, Dag Øystein
The effects of oil spills on marine biological systems are of great concern, especially in regions with high biological production of harvested resources such as in the Northeastern Atlantic. The scientific studies of the impact of oil spills on fish stocks tend to ignore that spatial patterns of natural mortality may influence the magnitude of the impact over time. Here, we first illustrate how spatial variation in natural mortality may affect the population impact by considering a thought experiment. Second, we consider an empirically based example of Northeast Arctic cod to extend the concept to a realistic setting. Finally, we present a scenario-based investigation of how the degree of spatial variation in natural mortality affects the impact over a gradient of oil spill sizes. Including the effects of spatial variations in natural mortality tends to widen the impact distribution, hence increasing the probability of both high and low impact events.
Mostrar más [+] Menos [-]Susceptibility of seagrass to oil spills: A case study with eelgrass, Zostera marina in San Francisco Bay, USA Texto completo
2017
Fonseca, Mark | Piniak, Gregory A. | Cosentino-Manning, Natalie
Existing literature illustrates inconsistent responses of seagrasses to oil exposure, both in the field and in the laboratory. Here, we add a new study that combined morphometric, demographic and photophysiology assessments to determine the potential oiling impacts to eelgrass (Zostera marina) from the 2007 Cosco Busan event in San Francisco Bay. Shoot densities, reproductive status, and rhizome elongation of Z. marina were examined at sites with pre-spill data, and eelgrass photosynthetic efficiency was measured post-spill. Shoot densities and percent elongation of rhizome internodes formed after the oil spill varied but with no consistent relationship to adjacent shoreline cleanup assessment team (SCAT) oiling categories. Similarly, differences in seagrass photosynthetic efficiency were not consistent with SCAT oiling categories. While thresholds for negative impacts on seagrass in general remain to be defined, conclusive oiling indicators for degree and duration of exposure would be important considerations and need examination under controlled study.
Mostrar más [+] Menos [-]Spatial and seasonal trends of polychlorinated dioxins, furans and dioxin-like polychlorinated biphenyls in air using passive and active samplers and inhalation risk assessment Texto completo
2017
Francisco, Ana Paula | Nardocci, Adelaide Cássia | Tominaga, Maria Yumiko | da Silva, Camila Rodrigues | Assunção, João Vicente de
Thirty-five and eleven air samples were collected using, respectively, active samplers (filter + PUF) and passive samplers (PUF disks), over two consecutive four-month periods (spring and autumn-winter), in urban, urban/industrial, and rural (background) sites in São Paulo, Brazil. All the samples were extracted with toluene:acetone (9:1) in a Soxhlet apparatus, and the extracts were then purified. Analysis for polychlorinated dioxins and furans (PCDD/Fs) and for dioxin-like polychlorinated biphenyls (dl-PCBs) were made by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC-HRMS). Human exposure risk was evaluated using inhalation risk assessment. Results showed: (1) there are statistical differences for PCDD/F concentrations in air between periods 1 and 2 (p = 0.03), whereas dl-PCB levels were not statistically different (p = 0.52); (2) PCDD/F and dl-PCB air levels were in the following order: urban/industrial > urban > rural for both active and passive samples; (3) PCDD/F and dl-PCB concentrations ranged from 7.76 to 453 fg TEQ/m³ in active air samples, and from 6.11 to 469 fg TEQ/m³ in passive air samples; (4) sampling rates for PCDD/Fs by the two approaches used showed considerable differences; (5) average daily intake by inhalation ranged from 18.1 to 55.6 fg TEQ/kg day, respectively, for adults and children, representing 1.8–5.6% of the lower range of the Tolerable Daily Intake recommended by the World Health Organization. Based on these results, the inhalation risk for PCDD/Fs and dl-PCBs, for local São Paulo residents, should be considered low.
Mostrar más [+] Menos [-]Perfluorocarbon emissions from electrolytic reduction of rare earth metals in fluoride/oxide system Texto completo
2017
Lizhi, Zhang | Xiufeng, Wang | Bin, Gong
Perfluorocarbons (PFC) are important greenhouse gas. In the aluminum electrolysis industry, PFC emission had been valued. The electrolytic reduction of rare earth metals in fluoride/oxide system with carbon anode and tungsten cathode also has PFC emission. But the PFC emission in rare earth metals industry received less attention. The PFC emissions during the electrolysis were studied by tracking the change of CF4 concentration in the flue gas of neodymium electrolysis and dysprosium-iron alloy electrolysis. The results showed that there were continuous CF4 overflows in the electrolysis process. The CF4 was outburst when anode effect occurred. The anode effect was always accompanied with the low electrolysis temperature. In addition, because of the electrolytic dysprosium-iron alloy requires higher cell voltage, the PFC emissions are higher than rare earth electrolysis. In general, PFC emissions from rare earth metal electrolysis are quite same as the aluminum electrolysis industry.
Mostrar más [+] Menos [-]Phosphorus effects on radial oxygen loss, root porosity and iron plaque in two mangrove seedlings under cadmium stress Texto completo
2017
Dai, Minyue | Liu, Jingchun | Liu, Wenwen | Lu, Haoliang | Jia, Hui | Hong, Hualong | Yan, Chongling
Phosphorus is an indispensable element for plants, but its role in alleviating the cadmium toxicity of mangrove seedlings is poorly documented. In this study, mangrove seedlings were grown in hydroponics and exposed to various Cd and P treatments. Data suggested that the inhibitory effect of Cd on the rate of radial oxygen loss and root porosity was alleviated by P. A. marina had a higher rate of ROL and POR, indicating that it had a stronger adaptability to anaerobic environment. K. obovata induced a higher Fe concentration in iron plaque under co-application of Cd and P, which may relate to higher biomass. Furthermore, P increased Cd concentration in iron plaque, implying that iron plaque can be an obstacle to prevent Cd entering into the plant, but most Cd was still distributed in its roots. These findings highlight a novel mechanism of Cd detoxification with P addition in mangrove seedlings.
Mostrar más [+] Menos [-]Underestimation of chemical contamination in marine fish muscle tissue can be reduced by considering variable wet:dry weight ratios Texto completo
2017
Cresson, Pierre | Travers-Trolet, Morgane | Rouquette, Manuel | Timmerman, Charles-André | Giraldo, Carolina | Lefebvre, Sébastien | Ernande, Bruno
Underestimation of chemical contamination in marine fish muscle tissue can be reduced by considering variable wet:dry weight ratios Texto completo
2017
Cresson, Pierre | Travers-Trolet, Morgane | Rouquette, Manuel | Timmerman, Charles-André | Giraldo, Carolina | Lefebvre, Sébastien | Ernande, Bruno
Whether considered as a risk for human health or as ecological tracers, contaminants' concentrations measured in fish muscles are commonly expressed relative to wet or dry mass. Comparison of results required conversion factors (CF) but accurate values are scarce and case-specific. The present paper is aimed at investigating errors linked with the use of the theoretical value. Muscles dry and wet masses were measured in 15 fish species to determine the actual CF. Most CF were lower than the theoretical wet:dry ratio of 5 classically used, with variations at individual and species level. Muscle lipid content (inferred by C/N ratios) was a crucial factor explaining discrepancies, claiming for caution when working with lipid-rich species. The observed variability demonstrated that using the theoretical CF may be inaccurate, when actual CF largely differs from the theoretical value. Dedicated measurement is the better approach when accuracy is required.
Mostrar más [+] Menos [-]Underestimation of chemical contamination in marine fish muscle tissue can be reduced by considering variable wet:dry weight ratios Texto completo
2017
Cresson, Pierre | Travers-trolet, Morgane | Rouquette, Manuel | Timmerman, Charles-andre | Giraldo, Carolina | Lefebvre, Sebastien | Ernande, Bruno
Whether considered as a risk for human health or as ecological tracers, contaminants' concentrations measured in fish muscles are commonly expressed relative to wet or dry mass. Comparison of results required conversion factors (CF) but accurate values are scarce and case-specific. The present paper is aimed at investigating errors linked with the use of the theoretical value. Muscles dry and wet masses were measured in 15 fish species to determine the actual CF. Most CF were lower than the theoretical wet:dry ratio of 5 classically used, with variations at individual and species level. Muscle lipid content (inferred by C/N ratios) was a crucial factor explaining discrepancies, claiming for caution when working with lipid-rich species. The observed variability demonstrated that using the theoretical CF may be inaccurate, when actual CF largely differs from the theoretical value. Dedicated measurement is the better approach when accuracy is required.
Mostrar más [+] Menos [-]Bioturbation transports secondary microplastics to deeper layers in soft marine sediments of the northern Baltic Sea Texto completo
2017
Näkki, Pinja | Setälä, Outi | Lehtiniemi, Maiju
Microplastics (MPs) are observed to be present on the seafloor ranging from coastal areas to deep seas. Because bioturbation alters the distribution of natural particles on inhabited soft bottoms, a mesocosm experiment with common benthic invertebrates was conducted to study their effect on the distribution of secondary MPs (different-sized pieces of fishing line<1mm). During the study period of three weeks, the benthic community increased MP concentration in the depth of 1.7–5.1cm in the sediment. The experiment revealed a clear vertical gradient in MP distribution with their abundance being highest in the uppermost parts of the sediment and decreasing with depth. The Baltic clam Macoma balthica was the only study animal that ingested MPs. This study highlights the need to further examine the vertical distribution of MPs in natural sediments to reliably assess their abundance on the seafloor as well as their potential impacts on benthic communities.
Mostrar más [+] Menos [-]Aliphatic and polycyclic aromatic hydrocarbons in surface sediments collected from mangroves with different levels of urbanization in southern Brazil Texto completo
2017
Assunção, Maíra Algarve | Frena, Morgana | Santos, Ana Paula Stein | dos Santos Madureira, Luiz Augusto
Three mangroves located in southern Brazil, Carijós (CA), Rio Tavares (RT) and Itacorubi (ITA), with distinct anthropogenic influences, were assessed with regard to the presence of aliphatic and polycyclic aromatic hydrocarbons (PAH). In this study, the n-alkane concentrations ranged from 1.9μg g−1 (CA) to 55.6μg g−1 (ITA) (dry weight). The carbon preference index (CPI) ranged from 2.1 to 7.9 and values for the terrestrial/aquatic ratio (TAR) were >1. Thus, both indexes indicated the predominance of sediment of terrestrial origin, mainly comprised of higher plants. Concentrations of total PAH ranged from 6.8ng g−1 (RT) to 437.3ng g−1 (ITA). The PAH isomeric ratios indicated that these compounds originated mainly from pyrogenic sources. Nevertheless, levels of n-alkanes in the three mangroves were relatively low and they are considered typical of uncontaminated surface sediments, while the level of contamination with PAH was classified as low to moderate.
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