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Resultados 1601-1610 de 4,308
Impact of an experimental eutrophication on the processes of bioerosion on the reef: One Tree Island, Great Barrier Reef, Australia Texto completo
2017
Chazottes, Veronique | Hutchings, Pat | Osorno, Alicia
The components of bioerosion were investigated during ENCORE (The Effect of Nutrient Enrichment on Coral Reefs) over 2years of controlled additions of dissolved inorganic nitrogen and phosphorus. The study was carried out at One Tree Island, southern Great Barrier Reef, Australia. Rates of microbioerosion and external erosion by grazing were significantly higher at the enriched sites than at the control sites. Rates of accretion by coralline algae were also significantly higher at enriched sites. In contrast, rates of macroboring were not significantly different between enriched and control sites.This study highlights the importance of improving water quality on the reef to reduce rates of bioerosion given that quantities of dead coral substrates have recently substantially increased as a result of coral bleaching (Hughes et al., 2015) and several Crown of Thorns plagues (Fabricius et al., 2010; De'ath et al., 2012), on the Great Barrier Reef.
Mostrar más [+] Menos [-]Characteristics of picoplankton abundances during a Thalassiosira diporocyclus bloom in the Taiwan Bank in late winter Texto completo
2017
Jiang, Xin | Li, Jiajun | Ke, Zhixin | Xiang, Chenhui | Tan, Yehui | Huang, Liangmin
To understand the variations of picoplankton (Prochlorococcus, Synechococcus, picoeukaryotes, and heterotrophic bacteria) abundances during diatom bloom, the distribution of picoplankton in the Taiwan Bank, South China Sea was investigated using flow cytometry during a Thalassiosira diporocyclus bloom in March 2016. The results indicated an abrupt abundance decrease for Prochlorococcus, Synechococcus, and picoeukaryotes within the bloom area while the abundance of heterotrophic bacteria showed no significant difference between the bloom and non-bloom areas. We found two sub-groups of heterotrophic bacteria: high- and low-nucleic acid content (HNA and LNA) bacteria with HNA dominated in the bloom area whereas LNA dominated in the non-bloom area. Among the picoplankton components, HNA represented the highest (61.1%) carbon biomass in the bloom area while picoeukaryotes represented the highest (37.6%) in the non-bloom area. Our findings implied that heterotrophic bacteria, especially HNA, played an essential role during the diatom bloom.
Mostrar más [+] Menos [-]Inhalation - Route of EDC exposure in seabirds (Larus argentatus) from the Southern Baltic Texto completo
2017
Falkowska, Lucyna | Grajewska, Agnieszka | Staniszewska, Marta | Nehring, Iga | Szumiło-Pilarska, Emilia | Saniewska, Dominika
Despite the presence of endocrine disrupting mercury, PAHs, alkylphenols and bisphenol A in inhaled air, scientific literature lacks information on their penetration into the lungs. Large lung capacity in birds makes this route of penetration more significant than in other animals.The studies were conducted on lungs of herring gulls found in the Gulf of Gdansk area. The results were juxtaposed with other tissues, including the intestines, which reflect the main, alimentary penetration route of harmful substances into the organism. It was determined that the capacity of bird's lungs, affects the efficiency with which mercury is absorbed from the air. Birds found to have high mercury concentrations in lungs had low PAHs concentrations, what was determined by the fact that the birds foraged in two different areas, as well as on different trophic levels. The alimentary route of phenol derivatives into the organism was of greater significance than inhalation.
Mostrar más [+] Menos [-]Associations between metal exposure and lesion formation in offshore Gulf of Mexico fishes collected after the Deepwater Horizon oil spill Texto completo
2017
Granneman, Jennifer E. | Jones, David L. | Peebles, Ernst B.
The objectives of this study were to: (1) examine patterns of short- and long-term metal exposure within the otoliths of six offshore fish species in varying states of health, as indicated by the presence of external skin lesions, and (2) determine if there was a change in otolith metal concentrations concurrent with the Deepwater Horizon (DWH) oil spill. Otoliths collected from 2011 to 2013 in the Gulf of Mexico (GOM) were analyzed for a suite of trace metals known to be associated with DWH oil. We found that lesioned fish often had elevated levels of otolith 60Ni and 64Zn before, during, and after the DWH oil spill. In addition, metal exposure varied according to species-specific life history patterns. These findings indicate that lesioned individuals were exposed to a persistent source of trace-metals in the GoM prior to the oil spill.
Mostrar más [+] Menos [-]Are environmental risk estimations linked to the actual environmental impact? Application to an oil handling facility (NE Spain) Texto completo
2017
Valdor, Paloma F. | Puente, Araceli | Gómez, Aina G. | Ondiviela, Bárbara | Juanes, J. A. (José A.)
The environmental risk analysis of aquatic systems includes the evaluation of the likelihood that adverse ecological effects may occur as a result of exposure to one or more stressors. In harbor areas, pollution is provided by a complex mixture of substances with different levels of toxicity, persistence and bioaccumulation, which complicates the hazards characterization and their multiple effects. A study of the relationship between the environmental impact and the environmental risk assessment at a specific isolated oil handling facility was undertaken. The environmental risk of the oil handling facility, considering the consequences of specific pollutants, was estimated and the associated environmental impact was quantified based on a ‘weights of evidence’ approach. The contamination quantified at the potentially affected area around the monobuoy of Tarragona has proved to be related with environmental risk estimations but the lines of evidence obtained do not allow us to assert that the activity developed at this facility has an associated environmental impact.
Mostrar más [+] Menos [-]The impact of two oil spill events on the water quality along coastal area of Kenting National Park, southern Taiwan Texto completo
2017
Chen, Chung-Chi | Tew, Kwee Siong | Ho, Ping-Ho | Ko, Fung-Chi | Hsieh, Hung-Yen | Meng, Pei-Jie
In 2009, the container ship Colombo Queen and the oil tanker W-O BUDMO grounded off Jialeshui and Houwan, respectively, in southern Taiwan. Water quality was monitored at each site to evaluate the environmental impact caused by the resulting oil spills. The results show that the PAHs, turbidity, and other nutrients increased shortly after oil spill, however levels of these parameters eventually returned to baseline levels. On the other hand, DO saturation, pH and chl. a decreased initially, reached maxima after 10days, and returned to the baseline levels after 14days. The chl. a concentration, pH and DO saturation fluctuated in a similar pattern at both sites during the oil spills, likely driven by algal blooms. In this study, we documented a full environmental recovery at coastal areas before, during and after the oil spills.
Mostrar más [+] Menos [-]An ecotoxicological approach to evaluate the effects of tourism impacts in the Marine Protected Area of La Maddalena (Sardinia, Italy) Texto completo
2017
Moschino, V. | Schintu, M. | Marrucci, A. | Marras, B. | Nesto, N. | Da Ros, L.
In the Marine Protected Area of La Maddalena Archipelago, environmental protection rules and safeguard measures for nautical activities have helped in reducing anthropogenic pressure; however, tourism related activities remain particularly significant in summer. With the aim of evaluating their impacts, the biomarker approach using transplanted Mytilus galloprovincialis as sentinel organisms coupled with POCIS deployment was applied. Mussels, translocated to four marine areas differently impacted by tourism activities, were sampled before, during and after the tourist season. Moreover, endocrine disruptors in passive samplers POCIS and the cellular toxicity of whole POCIS extracts on mussel haemocytes were evaluated to integrate ecotoxicological information. Lysosomal biomarkers, condition index and mortality rate, as well as metals in tissues suggested an alteration of the health status of mussels transplanted to the most impacted sites. The cellular toxicity of POCIS extracts was pointed out, notwithstanding the concentrations of the examined compounds were always below the detection limits.
Mostrar más [+] Menos [-]Estimating oil pollution risk in environmentally sensitive areas of petrochemical terminals based on a stochastic numerical simulation Texto completo
2017
Xie, Cheng | Deng, Jian | Zhuang, Yuan | Sun, Hao
This paper presents a method based on the oceanic current model and the oil spill model to evaluate the pollution risk of sensitive resources when oil spills occur. Moreover, this study proposes a novel impact index based on the risk theory to improve the risk assessment accuracy. The impact probability and the first impact time of the oil spill are calculated through a stochastic numerical simulation. The risk assessment content is enriched by establishing an impact model that considers the impact of sensitive index and spillage. Finally, the risk score of sensitive resources in an oil spill accident is visualized for formulating a scientific and effective protection priority order in a contamination response strategy. This study focuses on integrating every possible impact factor that plays a role in risk assessment and helps to provide a better theoretical support for protecting sensitive resources.
Mostrar más [+] Menos [-]Near-surface distribution of pollutants in coastal waters as assessed by novel polyethylene passive samplers Texto completo
2017
Aminot, Yann | Belles, Angel | Alary, Claire | Readman, James W.
We report a novel and inexpensive method to provide high resolution vertical measurements of temporally integrated organic contaminants in surface and sub-surface waters in polluted coastal environments. It employs a strip of polyethylene deployed as a passive sampler. Verifications are confirmed via conventional spot sample analyses and against Performance Reference Compound (PRC) calibration methods. Analytes targeted include 16 Polycyclic Aromatic Hydrocarbons, 15 personal care products, 8 organophosphorus flame retardants, 4 antifouling ‘booster’ biocides and 15 n-alkanes. Whilst all contaminants typically revealed homogeneous concentrations from 10 cm to 3 m depth in the selected harbour (<30% variations), many increased sharply at the air-sea interface. The passive sampler was shown to afford better resolution than could be achieved using conventional analytical techniques at the surface microlayer (SML). Whilst hydrophobicity appeared to be a key factor for the enrichment of many determinants, less correlation was found for the emerging contaminants.
Mostrar más [+] Menos [-]Litter assessment on 99 Cuban beaches: A baseline to identify sources of pollution and impacts for tourism and recreation Texto completo
2017
Botero, C.M. | Anfuso, G. | Milanes, C. | Cabrera, A. | Casas, G. | Pranzini, E. | Williams, A.T.
Litter presence was assessed on the entire Cuban coastline, and includes 99 beaches from all Cuban regions, during field work carried out in 2012 and 2015. A standard method verified in several countries was applied, which classified beaches for nine types of litter into four grades (A-excellent to D-poor). Almost half of the Cuban beaches obtained excellent cleanliness scores, although many needed to be better managed. In this baseline, the most common types of residue were general litter (8% grade D and 35% grades B/C) and potentially harmful litter (<68% with grade A). Resort beaches and those with international visitors showed the best litter management. Tourism Impacts seems to be related to visitor origin therefore choices to develop sustainable tourism in rural and village beaches (64%) appears low, if beach cleaning gross investment is focused on resort beaches (24%). Finally, this paper highlights geographical distribution and types of litter patterns.
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