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Offshore platforms: Comparison of five benthic indicators for assessing the macrozoobenthic stress levels
2014
Spagnolo, A. | Punzo, E. | Santelli, A. | Scarcella, G. | Strafella, P. | Grati, F. | Fabi, G.
Within the European Water Framework Directive, many studies have been conducted to evaluate the sensitivity/robustness of a variety of indices in relation to natural or anthropogenic disturbance events. However, these indices have rarely been applied to verify the impacts of disturbances in offshore environments, though the Marine Strategy Framework Directive recommends their use for assessing benthic community conditions and functionality. The aim of this paper was to determine which biotic indicator performed the best for detecting the impacts of offshore structures on benthic populations in the Adriatic Sea. The impacts of four rigs were investigated six months after their installation, and the H′, AMBI, m-AMBI, BENTIX, and BOPA indices were assessed. Although these five indices delivered some contradictory results because of the differences in their structure and discrepancies in their assignment of species sensitivity, the BENTIX, H′ and BOPA indices appear to evaluate stress levels better than the AMBI and m-AMBI indices, which tend to provide results that are slightly overly optimistic.
Afficher plus [+] Moins [-]Study of pollutant distribution in the Guaxindiba Estuarine System – SE Brazil
2014
Fonseca, E.M. | Baptista Neto, J.A. | Pereira, M.P.S. | Silva, C.G. | Arantes Junior, J.D.
The Guaxindiba Estuarine System is located in the northeast portion of Guanabara Bay. Despite the location inside an environmental protection zone, the main affluent of the river runs through the extremely urbanized area of the cities of Niterói and São Gonçalo. In order to understand the contamination levels of the estuary, 35 surface sediment samples were collected along the river and estuarine area and analyzed for the presence of heavy metals, PAHs, organochlorated pesticides, polychlorinated biphenyl and other contaminants. The analyzed data revealed a greatly affected environment with respect to most of these substances. The results suggested propitious deposits of contaminants, with high concentrations of organic matter and fine sediment. The levels of heavy metal in the entire estuarine system were high compared with the local background. The total mean concentrations of As, Cd, Pb, Cu, Zn, Hg, Cr and Ni in the surface sediments were: 3.74; 0.03; 19.3; 15.0; 99.0; n.d.; 29.0; and 22.0mg/kg, respectively, confirming, in certain cases, the high capacity of the environment to concentrate pollution.
Afficher plus [+] Moins [-]Cryptosporidium and Giardia in tropical recreational marine waters contaminated with domestic sewage: Estimation of bathing-associated disease risks
2014
Betancourt, Walter Q. | Duarte, Diana C. | Vásquez, Rosa C. | Gurian, Patrick L.
Sewage is a major contributor to pollution problems involving human pathogens in tropical coastal areas. This study investigated the occurrence of intestinal protozoan parasites (Giardia and Cryptosporidium) in tropical recreational marine waters contaminated with sewage. The potential risks of Cryptosporidium and Giardia infection from recreational water exposure were estimated from the levels of viable (oo) cysts (DIC+, DAPI+, PI−) found in near-shore swimming areas using an exponential dose response model. A Monte Carlo uncertainty analysis was performed in order to determine the probability distribution of risks. Microbial indicators of recreational water quality (enterococci, Clostridium perfringens) and genetic markers of sewage pollution (human-specific Bacteroidales marker [HF183] and Clostridium coccoides) were simultaneously evaluated in order to estimate the extent of water quality deterioration associated with human wastes. The study revealed the potential risk of parasite infections via primary contact with tropical marine waters contaminated with sewage; higher risk estimates for Giardia than for Cryptosporidium were found. Mean risks estimated by Monte Carlo were below the U.S. EPA upper bound on recreational risk of 0.036 for cryptosporidiosis and giardiasis for both children and adults. However, 95th percentile estimates for giardiasis for children exceeded the 0.036 level. Environmental surveillance of microbial pathogens is crucial in order to control and eradicate the effects that increasing anthropogenic impacts have on marine ecosystems and human health.
Afficher plus [+] Moins [-]Simulation of the potential effects of CO2 leakage from carbon capture and storage activities on the mobilization and speciation of metals
2014
de Orte, Manoela Romanó | Sarmiento, Aguasanta M. | DelValls, T Ángel | Riba, Inmaculada
One of the main risks associated with carbon capture and storage (CCS) activities is the leakage of the stored CO2, which can result in several effects on the ecosystem. Laboratory-scale experiments were performed to provide data on the possible effects of CO2 leakage from CCS on the mobility of metals previously trapped in sediments. Metal-contaminated sediments were collected and submitted to acidification by means of CO2 injection using different pH treatments. The test lasted 10days, and samples were collected at the beginning and at the end of the experiment for metal analysis. The results revealed increases in the mobility of metals such as Co, Cu, Fe, Pb and Zn due to pH decreases. Geochemical modeling demonstrated that acidification influenced the speciation of the metals, increasing the concentrations of their free forms. These data suggest the possible sediment contamination consequences of accidental CO2 leakage during CCS activities.
Afficher plus [+] Moins [-]A temporal and spatial assessment of TBT concentrations at dredged material disposal sites around the coast of England and Wales
2014
Bolam, Thi | Barry, Jon | Law, Robin J. | James, David | Thomas, Boby | Bolam, Stefan G.
Despite legislative interventions since the 1980s, contemporary concentrations of organotin compounds in marine sediments still impose restrictions on the disposal of dredged material in the UK. Here, we analyse temporal and spatial data to assess the effectiveness of the ban on the use of TBT paints in reducing concentrations at disposal sites.At a national scale, there was a statistically significant increase in the proportion of samples in which the concentration was below the limit of detection (LOD) from 1998 to 2010. This was observed for sediments both inside and outside the disposal sites. However, this temporal decline in organotin concentration is disposal site-specific. Of the four sites studied in detail, two displayed significant increases in proportion of samples below LOD over time. We argue that site-specificity in the effectiveness of the TBT ban results from variations in historical practices at source and unique environmental characteristics of each site.
Afficher plus [+] Moins [-]Monitoring in the Western Pacific region shows evidence of seagrass decline in line with global trends
2014
Short, Frederick T. | Coles, Robert | Fortes, Miguel D. | Victor, Steven | Salik, Maxwell | Irwan Isnain, | Andrew, Jay | Seno, Aganto
Seagrass systems of the Western Pacific region are biodiverse habitats, providing vital services to ecosystems and humans over a vast geographic range. SeagrassNet is a worldwide monitoring program that collects data on seagrass habitats, including the ten locations across the Western Pacific reported here where change at various scales was rapidly detected. Three sites remote from human influence were stable. Seagrasses declined largely due to increased nutrient loading (4 sites) and increased sedimentation (3 sites), the two most common stressors of seagrass worldwide. Two sites experienced near-total loss from of excess sedimentation, followed by partial recovery once sedimentation was reduced. Species shifts were observed at every site with recovering sites colonized by pioneer species. Regulation of watersheds is essential if marine protected areas are to preserve seagrass meadows. Seagrasses in the Western Pacific experience stress due to human impacts despite the vastness of the ocean area and low development pressures.
Afficher plus [+] Moins [-]Assessing coastal reclamation suitability based on a fuzzy-AHP comprehensive evaluation framework: A case study of Lianyungang, China
2014
Feng, Lan | Zhu, Xiaodong | Sun, Xiang
Coastal reclamation suitability evaluation (CRSE) is a difficult, complex and protracted process requiring the evaluation of many different criteria. In this paper, an integrated framework employing a fuzzy comprehensive evaluation method and analytic hierarchy process (AHP) was applied to the suitability evaluation for coastal reclamation for future sustainable development in the coastal area of Lianyungang, China. The evaluation results classified 6.63%, 22.99%, 31.59% and 38.79% of the coastline as suitable, weakly suitable, unsuitable and forbidden, respectively. The evaluation results were verified by the marine pollution data and highly consistent with the water quality status. The fuzzy-AHP comprehensive evaluation method (FACEM) was found to be suitable for the CRSE. This CRSE can also be applied to other coastal areas in China and thereby be used for the better management of coastal reclamation and coastline protection projects.
Afficher plus [+] Moins [-]Out of sight, out of mind: Threats to the marine biodiversity of the Canary Islands (NE Atlantic Ocean)
2014
Riera, Rodrigo | Becerro, Mikel A. | Stuart-Smith, Rick D. | Delgado, Juan D. | Edgar, Graham J.
Lack of knowledge of the marine realm may bias our perception of the current status and threats to marine biodiversity. Less than 10% of all ecological literature is related to the ocean, and the information we have on marine species that are threatened or on the verge of extinction is scarce. This lack of information is particularly critical for isolated areas such as oceanic archipelagos. Here we review published and grey literature on the current status of marine organisms in the Canary Islands as a case description of the consequences that current out-of-sight out-of-mind attitudes may have on this unique environment. Global change, as represented by coastal development, pollution, exotic species and climate change, are currently affecting the distribution and abundance of Canarian marine organisms, and pose multiple threats to local species and communities. Environmental risks are significant at community and species levels, particularly for threatened species. Failure to address these trends will result in shifts in local biodiversity with important ecological, social, and economic consequences. Scientists, policy makers, educators, and relevant societal groups need to collaborate to reverse deleterious coastal biodiversity trends.
Afficher plus [+] Moins [-]The effect of sand composition on the degradation of buried oil
2014
Fernández-Fernández, Sandra | Bernabeu, Ana M. | Rey, Daniel | Mucha, Ana P. | Almeida, C. Marisa R. | Bouchette, Frédéric
The potential effects of the mineralogical composition of sediment on the degradation of oil buried on sandy beaches were investigated. Toward that purpose, a laboratory experiment was carried out with sandy sediment collected along NW Iberian Peninsula beaches, tar-balls from the Prestige oil spill (NW Spain) and seawater. The results indicate that the mineralogical composition is important for the physical appearance of the oil (tar-balls or oil coatings). This finding prompted a reassessment of the current sequence of degradation for buried oil based on compositional factors. Moreover, the halo development of the oil coatings might be enhanced by the carbonate concentration of the sand. These findings open new prospects for future monitoring and management programs for oiled sandy beaches.
Afficher plus [+] Moins [-]Underwater noise pollution in a coastal tropical environment
2014
Bittencourt, L. | Carvalho, R.R. | Lailson-Brito, J. | Azevedo, A.F.
Underwater noise pollution has become a major concern in marine habitats. Guanabara Bay, southeastern Brazil, is an impacted area of economic importance with constant vessel traffic. One hundred acoustic recording sessions took place over ten locations. Sound sources operating within 1km radius of each location were quantified during recordings. The highest mean sound pressure level near the surface was 111.56±9.0dB re 1μPa at the frequency band of 187Hz. Above 15kHz, the highest mean sound pressure level was 76.21±8.3dB re 1μPa at the frequency 15.89kHz. Noise levels correlated with number of operating vessels and vessel traffic composition influenced noise profiles. Shipping locations had the highest noise levels, while small vessels locations had the lowest noise levels. Guanabara Bay showed noise pollution similar to that of other impacted coastal regions, which is related to shipping and vessel traffic.
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