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A study of anthropogenic and climatic disturbance of the New River Estuary using a Bayesian belief network 全文
2014
Nojavan A., Farnaz | Qian, Song S. | Paerl, Hans W. | Reckhow, Kenneth H. | Albright, Elizabeth A.
The present paper utilizes a Bayesian Belief Network (BBN) approach to intuitively present and quantify our current understanding of the complex physical, chemical, and biological processes that lead to eutrophication in an estuarine ecosystem (New River Estuary, North Carolina, USA). The model is further used to explore the effects of plausible future climatic and nutrient pollution management scenarios on water quality indicators. The BBN, through visualizing the structure of the network, facilitates knowledge communication with managers/stakeholders who might not be experts in the underlying scientific disciplines. Moreover, the developed structure of the BBN is transferable to other comparable estuaries. The BBN nodes are discretized exploring a new approach called moment matching method. The conditional probability tables of the variables are driven by a large dataset (four years). Our results show interaction among various predictors and their impact on water quality indicators. The synergistic effects caution future management actions.
显示更多 [+] 显示较少 [-]De novo transcriptomic profile in the gonadal tissues of the intertidal whelk Reishia clavigera 全文
2014
Ho, Kevin K.Y. | Leung, Priscilla T.Y. | Ip, Jack C.H. | Qiu, J.W. | Leung, Kenneth M.Y.
The intertidal whelk Reishia clavigera (formerly named as Thais clavigera) is one of the most sensitive species to organotin-associated imposex. However, the limited information on mRNA transcriptome of the species has restricted the molecular investigation on such endocrine disruption. By means of Illumina sequencing, we obtained a global de novo transcriptome from the gonadal tissues of both male and female R. clavigera, with 197,324 assembled transcripts and 151,684 condensed non-redundant transcripts. Blast hit results from the NCBI’s non-redundant molluscan database showed that 28,948 transcripts were successfully annotated with significant matches at an e-value of ⩽1e−6. Among them, 1108 transcripts were assigned a well-defined gene ontology term. As the first transcriptomic study on the gonadal tissues of R. clavigera, this study has enhanced the information of mRNA transcriptome on this species and will thus facilitate mechanistic studies of chemical contaminants (e.g., organotins) on this common biomonitor species.
显示更多 [+] 显示较少 [-]The environmental release and fate of antibiotics 全文
2014
Manzetti, Sergio | Ghisi, Rossella
Antibiotics have been used as medical remedies for over 50years and have recently emerged as new pollutants in the environment. This review encompasses the fate of several antibiotics in the environment, including sulfonamides, nitrofurans, terfenadines, cephalosporins and cyclosporins. It investigates the cycle of transfer from humans and animals including their metabolic transformation. The results show that antibiotic metabolites are of considerable persistence and are localized to ground-water and drinking water supplies. Furthermore, the results also show that several phases of the cycle of antibiotics in the environment are not well understood, such as how low concentrations of antibiotic metabolites in the diet affect humans and animals. This review also shows that improved wastewater decontamination processes are remediating factors for these emerging pollutants. The results obtained here may help legislators and authorities in understanding the fate and transformation of antibiotics in the environment.
显示更多 [+] 显示较少 [-]Courage under fire: Seagrass persistence adjacent to a highly urbanised city–state 全文
2014
Yaakub, Siti Maryam | McKenzie, Len J. | Erftemeijer, Paul L.A. | Bouma, Tjeerd | Todd, Peter A.
Due to increasing development Southeast Asia’s coastlines are undergoing massive changes, but the associated impacts on marine habitats are poorly known. Singapore, a densely populated island city–state, is a quintessential example of coastal modification that has resulted in the (hitherto undocumented) loss of seagrass. We reconstructed the historic extent and diversity of local seagrass meadows through herbarium records and backwards extrapolation from contemporary seagrass locations. We also determined the current status of seagrass meadows using long-term monitoring data and identified the main threats to their presence in Singapore. Results show that, even though ∼45% of seagrass has been lost during the last five decades, species diversity remains stable. The main cause of seagrass loss was, and continues to be, land reclamation. We conclude that strict controls on terrestrial runoff and pollution have made it possible for seagrass to persist adjacent to this highly urbanised city–state.
显示更多 [+] 显示较少 [-]Hierarchy of factors exerting an impact on nutrient load of the Baltic Sea and sustainable management of its drainage basin 全文
2014
Kiedrzyńska, Edyta | Jóźwik, Adam | Kiedrzyński, Marcin | Zalewski, Maciej
The aim of the paper was to evaluate 23 catchment factors that determine total phosphorus and total nitrogen load to the Baltic Sea. Standard correlation analysis and clustering were used. Both phosphorus and nitrogen loads were found to be positively related to the number of pigs and the human population associated with wastewater treatment plants (WWTPs) per km2, while the number of cattle and agricultural area were found to influence nitrogen rather than phosphorus load, and the area of forests is negatively related to loads of both nutrients. Clustering indicates an overall north–south pattern in the spatial co-occurrence of socio-ecological factors, with some exceptions discussed in the paper. Positive steps in the Baltic Sea region have already been taken, but much remains to be done. The development of coherent response policies to reduce eutrophication in the Baltic Sea should be based on a comprehensive knowledge base, an appropriate information strategy and learning alliance platform in each drainage river catchments.
显示更多 [+] 显示较少 [-]Metal contamination of estuarine intertidal sediments of Moreton Bay, Australia 全文
2014
Morelli, Guia | Gasparon, Massimo
Trace element concentrations in surface intertidal sediments were analyzed to assess the level of contamination along the western side of Moreton Bay (Australia). The environmental risks posed by metals were evaluated using sediment quality guidelines, the Risk Assessment Code (RAC) and enrichment relative to background levels. Chromium, Ni, and Cu are the main contributors to sediment pollution. Sediments are also enriched in Zn, Cd and Pb by 1.5–3 times the regional background. Zinc, Cd and Co may pose high to very high risk to the aquatic biota due to their potential bioavailability, while Ni, As, Cu, Pb and Cr may pose medium risk at some of the investigated sites. Results emphasize the importance of using different methods for the assessment of sediment pollution at an estuarine site.
显示更多 [+] 显示较少 [-]Deep-sea faunal communities associated with a lost intermodal shipping container in the Monterey Bay National Marine Sanctuary, CA 全文
2014
Taylor, Josi R. | DeVogelaere, Andrew P. | Burton, Erica Janis | Frey, Oren | Lundsten, Lonny | Kuhnz, Linda Ann | Whaling, P.J. | Lovera, Christopher | Buck, Kurt R. | Barry, James P.
Carrying assorted cargo and covered with paints of varying toxicity, lost intermodal containers may take centuries to degrade on the deep seafloor. In June 2004, scientists from Monterey Bay Aquarium Research Institute (MBARI) discovered a recently lost container during a Remotely Operated Vehicle (ROV) dive on a sediment-covered seabed at 1281m depth in Monterey Bay National Marine Sanctuary (MBNMS). The site was revisited by ROV in March 2011. Analyses of sediment samples and high-definition video indicate that faunal assemblages on the container’s exterior and the seabed within 10m of the container differed significantly from those up to 500m. The container surface provides hard substratum for colonization by taxa typically found in rocky habitats. However, some key taxa that dominate rocky areas were absent or rare on the container, perhaps related to its potential toxicity or limited time for colonization and growth. Ecological effects appear to be restricted to the container surface and the benthos within ∼10m.
显示更多 [+] 显示较少 [-]Estimation of the annual flow and stock of marine debris in South Korea for management purposes 全文
2014
Jang, Yong Chang | Lee, Jongmyoung | Hong, Sunwook | Mok, Jin Yong | Kim, Kyoung-Shin | Lee, Yun Jeong | Choi, Hyun-Woo | Kang, Hongmook | Lee, Sukhui
The annual flow and stock of marine debris in the Sea of Korea was estimated by summarizing previous survey results and integrating them with other relevant information to underpin the national marine debris management plan. The annual inflow of marine debris was estimated to be 91,195tons [32,825tons (36% of the total) from sources on land and 58,370tons (64%) from ocean sources]. As of the end of 2012, the total stock of marine debris on all South Korean coasts (12,029tons), the seabed (137,761tons), and in the water column (2451tons) was estimated to be 152,241tons. In 2012, 42,595tons of marine debris was collected from coasts, seabeds, and the water column. This is a very rare case study that estimated the amount of marine debris at a national level, the results of which provide essential information for the development of efficient marine debris management policies.
显示更多 [+] 显示较少 [-]Enhancing the management response to oil spills in the Tuscany Archipelago through operational modelling 全文
2014
Janeiro, João | Zacharioudaki, Anna | Sarhadi, Ehsan | Neves, Augusto | Martins, Flavio
A new approach towards the management of oil pollution accidents in marine sensitive areas is presented in this work. A set of nested models in a downscaling philosophy was implemented, externally forced by existing regional operational products. The 3D hydrodynamics, turbulence and the oil transport/weathering models are all linked in the same system, sharing the same code, exchanging information in real time and improving its ability to correctly reproduce the spill. A wind-generated wave model is also implemented using the same downscaling philosophy. Observations from several sources validated the numerical components of the system. The results obtained highlight the good performance of the system and its ability to be applied for oil spill forecasts in the region. The success of the methodology described in this paper was underline during the Costa Concordia accident, where a high resolution domain was rapidly created and deployed inside the system covering the accident site.
显示更多 [+] 显示较少 [-]Enhanced methane emissions from oil and gas exploration areas to the atmosphere – The central Bohai Sea 全文
2014
Zhang, Yong | Zhao, Hua-de | Zhai, Wei-dong | Zang, Kun-peng | Wang, Ju-ying
The distributions of dissolved methane in the central Bohai Sea were investigated in November 2011, May 2012, July 2012, and August 2012. Methane concentration in surface seawater, determined using an underway measurement system combined with wavelength-scanned cavity ring-down spectroscopy, showed marked spatiotemporal variations with saturation ratio from 107% to 1193%. The central Bohai Sea was thus a source of atmospheric methane during the survey periods. Several episodic oil and gas spill events increased surface methane concentration by up to 4.7 times and raised the local methane outgassing rate by up to 14.6 times. This study demonstrated a method to detect seafloor CH4 leakages at the sea surface, which may have applicability in many shallow sea areas with oil and gas exploration activities around the world.
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