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Результаты 2451-2460 из 7,979
Rapid assessment tool for oil spill planning and contingencies
2021
Meza-Padilla, Rafael | Enriquez, Cecilia | Appendini, Christian M.
The Rapid Oil Spill Hazard Assessment is presented as a demonstration of concept for a tool providing a framework for managers and planners to assess potential impact areas of oil spills. The tool consists of precomputed oil spill scenarios derived from the analysis of twenty years of modeled current data using Self-Organizing Maps to identify 16 representative patterns. These patterns were used to provide boundary conditions for hydrodynamic and wave models to generate higher resolution current fields, used to drive a Lagrangian oil particle transport model creating the most probable oil spill dispersion patterns. To demonstrate the concept, the tool is applied to the Perdido region in the western Gulf of Mexico. A total of 896 oil spill simulations were performed, considering surface and bottom spills, and were stored in a database for easy access to map arrival probabilities and times to be used in risk and vulnerability analysis.
Показать больше [+] Меньше [-]Plastic ingestion by green turtles (Chelonia mydas) over 33 years along the coast of Texas, USA
2021
Choi, Daniel Y. | Gredzens, Christian | Shaver, Donna J.
Despite exponential growth of anthropogenic marine debris in recent decades, plastic ingestion by marine turtles in the Gulf of Mexico is not well understood. Gastrointestinal tracts were examined from 464 green turtles that stranded in Texas between 1987 and 2019, and 226 turtles ingested plastic (48.7%). This number doubled from 32.5% in 1987–1999 to 65.5% in 2019, but mass of ingested items was lowest in 2019. No turtles showed evidence of death directly related to plastic ingestion. Compared to other regions, plastic ingestion was low. Small turtles (<25 cm straight carapace length) ingested plastic more frequently and in greater amounts than larger turtles. Small turtles also ingested more hard plastic while larger turtles ingested more sheet-like and thread-like plastics, which may correspond to size-based habitat shifts. This is among the largest marine turtle ingestion studies to date and demonstrates an increasing prevalence of plastic ingestion.
Показать больше [+] Меньше [-]Sustainability manifesting as a multi-material and -sited network effect: How boat-sourced sewage management facilities serve as governance artefacts advancing sustainability in nautical tourism
2021
Vantola, Renne | Luoma, Emilia | Parviainen, Tuuli | Lehikoinen, Annukka
Marinas are a part of coastal areas' touristic appeal, but also hotspots for boat-sourced pollution. Considering the manifestation of sustainability in marina operation, we utilize actor-network theory (ANT) in demonstrating a conceptual systems analysis on boat-sourced sewage management (BSSM) as one important socio-eco-technical sub-system of sustainable nautical tourism. We describe a multi-material collective of dynamically interacting human and non-human entities to understand how and under what conditions BSSM facilities advance the sustainability of marina operation. Our analysis insightfully uncovers BSSM facilities as both core marina services and governance artefacts and reveals that managing boat-sourced sewage successfully is an outcome of a multi-sited network of heterogeneous elements that together enable both sustainable boating practices and marina operation. We suggest the presented ANT-based systemic thinking has potential for providing novel perspectives to sustainability analyses in diverse tourism-related contexts.
Показать больше [+] Меньше [-]Interactions between heavy metals and bacteria in mangroves
2021
Meng, Shanshan | Peng, Tao | Pratush, Amit | Huang, Tongwang | Hu, Zhong
Environmental heavy metal pollution has become a serious problem in recent years. Therefore, our study investigated seven heavy metal-contaminated mangroves (Beihai, Fangchenggang, Hainan, Hongkong, Shenzhen, Yunxiao, and Zhanjiang) in southern China, and found that they were particularly polluted with Zn and Pb. These heavy metals were mainly distributed in the surface sediments of the mangroves. Among these seven mangroves, the Shenzhen mangrove was the most polluted site, whereas the Beihai mangrove was the least polluted. Moreover, the bacterial communities in the mangroves were significantly associated with heavy metal contamination. For instance, Fusibacter was significantly correlated with Pb, Zn, Cu, Co, Ni, Cd, and Ag (P < 0.05, R = −0.47). Syntrophorhabdus was also significantly correlated with heavy metals (P < 0.05, R = 0.63). Furthermore, Geo-Chip analyses were conducted to demonstrate the involvement of many functional genes in heavy metal transport, particularly Ni transport. Our results also demonstrated that the heavy metals could be transported by various bacteria. For example, Pseudomonas and Burkholderia were involved in various heavy metal transportation mechanisms, particularly for Ni and Zn, suggesting that these bacteria could be used for heavy metal remediation. Therefore, our study provides insights into the interactions between bacterial communities and heavy metals, which could enable the development of novel mangrove protection strategies.
Показать больше [+] Меньше [-]Deepwater Horizon 2010: Subsea dispersants protected responders from VOC exposure
2021
Zhao, Lin | Mitchell, Douglas A. | Prince, Roger C. | Walker, Ann Hayward | Arey, J Samuel | Nedwed, Tim J.
Controversy remains on the use of Sub-Sea Dispersant Injection (SSDI) during the Deepwater Horizon (DWH) spill to minimize the exposure of responders on surface vessels to volatile organic compounds (VOC). Here, we use extensive evidence (>90,000 VOC measurements) collected near the oil well MC252 site during the DWH spill and demonstrate at a high level of statistical confidence that SSDI enhanced the safety and health conditions of the responders at the water surface through the reduction of airborne VOC concentrations in a dose-dependent manner. VOC levels on ships' decks were clearly diminished (p < 0.001) during subsea dispersant use, and incidents of peak concentrations (>50 ppm VOC) that could have been an immediate concern to worker health were reduced by a factor of ~6 to 19 when dispersants were delivered at the intended rate. SSDI thus played an important role in minimizing potential exposure to VOC, and should be embedded in guidelines and regulations for dispersant use.
Показать больше [+] Меньше [-]Decoupling of biotic and abiotic patterns in a coastal area affected by chronic metal micronutrients disturbances
2021
Glasner, B. | Henríquez-Castillo, C. | Alfaro, F.D. | Trefault, N. | Andrade, S. | De la Iglesia, R.
Coastal systems are highly productive areas for primary productivity and ecosystem services and host a large number of human activities. Since industrialization, metal micronutrients in these regions have increased. Phytoplankton use metals as micronutrients in metabolic processes, but in excess, had deleterious effects. In coastal systems, picoeukaryotes represent a diverse and abundant group with widespread distribution and fundamental roles in biogeochemical cycling. We combined different approaches to explore picoeukaryotes seasonal variability in a chronically metal polluted coastal area at the south-eastern Pacific Ocean. Through remote and field measurements to monitor environmental conditions and 18S rRNA gene sequencing for taxonomic profiling, we determined metal chronic effect on picoeukaryote community's structure. Our results revealed a stable richness and a variable distribution of the relative abundance, despite the physicochemical seasonal variations. These results suggest that chronic metal contamination influences temporal heterogeneity of picoeukaryote communities, with a decoupling between abiotic and biotic patterns.
Показать больше [+] Меньше [-]Spatial distribution and source identification of persistent organic pollutants in the sediments of the Yeşilırmak River and coastal area in the Black Sea
2021
Dinç, Burak | Çelebi, Ahmet | Avaz, Gülsen | Canlı, Oltan | Güzel, Bariş | Eren, Beytullah | Yetis, Ulku
Surface sediments from the Yeşilırmak River and the near coastal area in the Black Sea were collected using sediment traps to assess the spatial distributions of persistent organic pollutants and find their potential sources. Analyses were carried out to determine the concentrations of the persistent organic pollutants of seventeen polychlorinated dibenzo-p-dioxins and dibenzofurans, sixteen polycyclic aromatic hydrocarbons, seven polychlorinated biphenyls, and eight organochlorine pesticides using high-resolution gas chromatography–mass spectrometry and gas chromatography-tandem mass spectrometry systems. Analysis showed that the three main components of persistent organic pollutants (polychlorinated dibenzo-p-dioxins and dibenzofurans, polycyclic aromatic hydrocarbons, and organochlorine pesticides) primary sources are industrial activities. In addition, the widespread occurrence of persistent organic pollutants in the watershed surface sediments taken from the Yeşilırmak River basin showed that agricultural and urban areas are also diffuse persistent organic pollutants sources.
Показать больше [+] Меньше [-]Marine litter on a highly urbanized beach at Southeast Brazil: A contribution to the development of litter monitoring programs
2021
Ribeiro, Victor V. | Pinto, Mariana A.S. | Mesquita, Raul K.B. | Moreira, Lucas Buruaem | Costa, Monica F. | Castro, Ítalo Braga
Seasonal distribution of Marine Litter (ML) on Santos beaches was assessed using a citizen science strategy. Plastics and cigarette butts (CB) were the dominant items in all sampling campaigns. Seasonal distribution did not result in significant differences for most items. Plastic and CB amounts were high in summer compared to autumn. For all sampled sites the presence of beach users influenced ML densities. However, results showed that some sites presented an additional influence of local hydrodynamic. Moderate amounts of hazardous items including metal, glass, CB, sanitary waste and plastic tubes used to pack and market illicit drugs represented between 20.8 and 31% of all ML over the seasons. The beaches of Santos were classified as dirty in autumn and spring and as extremely dirty in winter and summer. These findings can serve as a baseline to support mitigating actions by public authorities and start monitoring programs of ML not only in Santos but also in other urbanized beaches.
Показать больше [+] Меньше [-]The intrusion of polluted Fly River mud into Torres Strait
2021
Wolanski, E. | Petus, C. | Lambrechts, J. | Brodie, J. | Waterhouse, J. | Tracey, D.
There is a concern that the Fly River plume from Papua New Guinea (PNG) may be delivering mine-derived polluted mud along the southern PNG coast into the northern Torres Strait, which is the northernmost extent of the Great Barrier Reef. To quantify this threat, the mud transport dynamics along the southern PNG coast were studied using the SLIM model. The model was qualitatively verified using historical field data on sediment dynamics and compared with more recent satellite-derived turbidity data. During strong south east winds and spring tides, about 5.4% of the Fly River mud discharge enters the Torres Strait, in agreement with previous field-derived results. The annual net movement of mud is westward, thus polluted Fly River mud progressively intrudes into Torres Strait. This intrusion is slow and may take a century to reach in significant quantities at Saibai Island, the nearest Australian island to the Fly River. Field data are needed to fully validate the model and provide greater confidence in these results.
Показать больше [+] Меньше [-]Legacy and emerging antifouling biocide residues in a tropical estuarine system (Espirito Santo state, SE, Brazil)
2021
Abreu, Fiamma Eugenia Lemos | Batista, Rodrigo Moço | Castro, Ítalo Braga | Fillmann, Gilberto
The contamination by antifouling biocide residues (booster biocides - diuron, Irgarol, chlorothalonil, dichlofluanid and DCOIT; butyltin compounds-BTs (TBT, DBT and MBT); and antifouling paint particles-APPs) was appraised in sediments of Vitoria Estuarine System (VES). Even at its historical lower (ΣBTs ≤113 ng Sn g⁻¹ dry wt), the current environmental levels of BTs in areas with a predominance of boatyards still pose a risk to the local biota and human population. DCOIT, among booster biocides, was the most frequently detected, especially in boatyards (≤40 ng g⁻¹ dry wt) and Vitoria Port (64 ng g⁻¹ dry wt), while APPs were also detected mainly in sediments of boatyards (≤5,969 μg g⁻¹ dry wt). Since levels of diuron and DCOIT in APPs were as high as 1,670,000 and 899,000 ng g⁻¹ dry wt, respectively, they are acting as secondary sources of these antifouling biocides. Therefore, VES is threatened by antifouling biocide residues due to the multiple diffuse sources of contamination, showing the need for more efforts on public policies (including temporal trend monitoring studies).
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