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Seasonal variations of biomarker responses in the marine blue mussel (Mytilus spp.) Texte intégral
2013
Schmidt, Wiebke | Power, Emma | Quinn, Brian
Biomarkers, which can detect changes at the biochemical level, have been used for many years as early warning tools in environmental monitoring. In order to distinguish between natural variability and the potential effects of anthropogenic pollution, it is essential to identify background levels and establish the potential influence of abiotic (season, temperature and salinity) and biotic (gametogenesis) factors. In this study, we examined various biomarkers of stress (glutathione S-transferase (GST)), reproduction (vitellin-like proteins) and damage (lipid peroxidation (LPO) and DNA damage (DNA)) in marine mussels (Mytilus spp.) from a known pristine hybrid zone. Levels of all biomarker expression varied between seasons and appeared to be linked to the reproductive cycle. Oxidative stress in winter, with low GST expression and a higher expression of LPO and DNA damage displayed could be explained by low food availability. These data provide vital baseline information for future ecotoxicological and environmental monitoring studies.
Afficher plus [+] Moins [-]Compliance of Royal Naval ships with nitrogen oxide emissions legislation Texte intégral
2013
Blatcher, D.J. | Eames, I.
Nitrogen oxide (NOx) emissions from marine diesel engines pose a hazard to human health and the environment. From 2021, demanding emissions limits are expected to be applied to sea areas that the Royal Navy (RN) accesses. We analyze how these future constraints affect the choice of NOx abatement systems for RN ships, which are subject to more design constraints than civilian ships. A weighted matrix approach is used to facilitate a quantitative assessment.For most warships to be built soon after 2021 Lean Nitrogen Traps (LNT) in conjunction with Exhaust Gas Recirculation (EGR) represents a relatively achievable option with fewer drawbacks than other system types. Urea-selective catalytic reduction is likely to be most appropriate for ships that are built to civilian standards. The future technologies that are at an early stage of development are discussed.
Afficher plus [+] Moins [-]Plastic ingestion in marine-associated bird species from the eastern North Pacific Texte intégral
2013
Avery-Gomm, S. | Provencher, J.F. | Morgan, K.H. | Bertram, D.F.
In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible.
Afficher plus [+] Moins [-]Coastal urbanization leads to remarkable seaweed species loss and community shifts along the SW Atlantic Texte intégral
2013
Scherner, Fernando | Horta, Paulo Antunes | de Oliveira, Eurico Cabral | Simonassi, José Carlos | Hall-Spencer, Jason M. | Chow, Fungyi | Nunes, José Marcos C. | Pereira, Sonia Maria Barreto
Coastal urbanization leads to remarkable seaweed species loss and community shifts along the SW Atlantic Texte intégral
2013
Scherner, Fernando | Horta, Paulo Antunes | de Oliveira, Eurico Cabral | Simonassi, José Carlos | Hall-Spencer, Jason M. | Chow, Fungyi | Nunes, José Marcos C. | Pereira, Sonia Maria Barreto
Coastal urbanization is rapidly expanding worldwide while its impacts on seaweed communities remain poorly understood. We assessed the impact of urbanization along an extensive latitudinal gradient encompassing three phycogeographical regions in the SW Atlantic. Human population density, number of dwellings, and terrestrial vegetation cover were determined for each survey area and correlated with diversity indices calculated from seaweed percent cover data. Urban areas had significantly lower calcareous algal cover (−38%), and there was significantly less carbonate in the sediment off urban areas than off reference areas. Seaweed richness averaged 26% less in urban areas than in areas with higher vegetation cover. We observed a remarkable decline in Phaeophyceae and a substantial increase of Chlorophyta in urban areas across a wide latitudinal gradient. Our data show that coastal urbanization is causing substantial loss of seaweed biodiversity in the SW Atlantic, and is considerably changing seaweed assemblages.
Afficher plus [+] Moins [-]Coastal urbanization leads to remarkable seaweed species loss and community shifts along the SW Atlantic | Marine Pollution Bulletin Texte intégral
2013
Scherner, Fernando | Horta, Paulo Antunes | Oliveira, Eurico Cabral de | Simonassi, José Carlos | Hall Spencer, Jason M. | Chow, Fungyi | Nunes, José Marcos de Castro | Pereira, Sônia Maria Barreto | Scherner, Fernando | Horta, Paulo Antunes | Oliveira, Eurico Cabral de | Simonassi, José Carlos | Hall Spencer, Jason M. | Chow, Fungyi | Nunes, José Marcos de Castro | Pereira, Sônia Maria Barreto
Texto completo: acesso restrito. p. 106–115 | Coastal urbanization is rapidly expanding worldwide while its impacts on seaweed communities remain poorly understood. We assessed the impact of urbanization along an extensive latitudinal gradient encompassing three phycogeographical regions in the SW Atlantic. Human population density, number of dwellings, and terrestrial vegetation cover were determined for each survey area and correlated with diversity indices calculated from seaweed percent cover data. Urban areas had significantly lower calcareous algal cover (−38%), and there was significantly less carbonate in the sediment off urban areas than off reference areas. Seaweed richness averaged 26% less in urban areas than in areas with higher vegetation cover. We observed a remarkable decline in Phaeophyceae and a substantial increase of Chlorophyta in urban areas across a wide latitudinal gradient. Our data show that coastal urbanization is causing substantial loss of seaweed biodiversity in the SW Atlantic, and is considerably changing seaweed assemblages.
Afficher plus [+] Moins [-]Allocation of marine environmental carrying capacity in the Xiamen Bay Texte intégral
2013
Liao, Enhui | Jiang, Yuwu | Yan, Xiao-Hai | Chen, Zhaoyun | Wang, Jia | Zhang, Luoping
Three optimization methods are employed to allocate Marine Environmental Carrying Capacity (MECC) in the Xiamen Bay. The hydrodynamic and pollutant fields are first simulated by the Princeton Ocean Model. Taking phosphorus as an index of the water quality, the response fields are then calculated. These response fields represent the relationship between the concentration of the sea zone and the pollution sources. Finally, MECC is optimized and distributed in the Xiamen Bay by three optimization methods. The results show classical linear optimization can only maximize the satisfaction level for one of the stake holders’, e.g., dischargers or environmental protection bureau, satisfaction level. However, the fuzzy and grey fuzzy optimizations can provide a compromise, and therefore a fairer result, by incorporating the conflicting goals of all of the different stakeholders. Compared with fuzzy optimization, the grey fuzzy optimization provides a more flexible choice for the decision-makers.
Afficher plus [+] Moins [-]Towards environmental management of water turbidity within open coastal waters of the Great Barrier Reef Texte intégral
2013
Macdonald, Rachael K. | Ridd, Peter V. | Whinney, James C. | Larcombe, Piers | Neil, David T.
Water turbidity and suspended sediment concentration (SSC) are commonly used as part of marine monitoring and water quality plans. Current management plans utilise threshold SSC values derived from mean-annual turbidity concentrations. Little published work documents typical ranges of turbidity for reefs within open coastal waters. Here, time-series turbidity measurements from 61 sites in the Great Barrier Reef (GBR) and Moreton Bay, Australia, are presented as turbidity exceedance curves and derivatives. This contributes to the understanding of turbidity and SSC in the context of environmental management in open-coastal reef environments. Exceedance results indicate strong spatial and temporal variability in water turbidity across inter/intraregional scales. The highest turbidity across 61 sites, at 50% exceedance (T50) is 15.3 NTU and at 90% exceedance (T90) 4.1 NTU. Mean/median turbidity comparisons show strong differences between the two, consistent with a strongly skewed turbidity regime. Results may contribute towards promoting refinement of water quality management protocols.
Afficher plus [+] Moins [-]Improving a prediction system for oil spills in the Yellow Sea: Effect of tides on subtidal flow Texte intégral
2013
Kim, Chang-Sin | Cho, Yang-Ki | Choi, Byoung-Ju | Jung, Kyung Tae | You, Sung Hyup
A multi-nested prediction system for the Yellow Sea using drifter trajectory simulations was developed to predict the movements of an oil spill after the MV Hebei Spirit accident. The speeds of the oil spill trajectories predicted by the model without tidal forcing were substantially faster than the observations; however, predictions taking into account the tides, including both tidal cycle and subtidal periods, were satisfactorily improved. Subtidal flow in the simulation without tides was stronger than in that with tides because of reduced frictional effects. Friction induced by tidal stress decelerated the southward subtidal flows driven by northwesterly winter winds along the Korean coast of the Yellow Sea. These results strongly suggest that in order to produce accurate predictions of oil spill trajectories, simulations must include tidal effects, such as variations within a tidal cycle and advections over longer time scales in tide-dominated areas.
Afficher plus [+] Moins [-]Assessment and management of heavy metal pollution in the marine environment of the Arabian Gulf: A review Texte intégral
2013
Naser, Humood A.
The Arabian Gulf is considered among the highest anthropogenically impacted regions in the world. Heavy metals contamination in coastal and marine environments is becoming an increasingly serious threat to both the naturally stressed marine ecosystems and humans that rely on marine resources for food, industry and recreation. Heavy metals are introduced to coastal and marine environments through a variety of sources and activities including sewage and industrial effluents, brine discharges, coastal modifications and oil pollution. The present paper reviews heavy metal contamination in a variety of marine organisms, and sediments, and suggests measures for environmental management of heavy metal pollution in the Arabian Gulf. Most of the reviewed literature confirmed that heavy metal concentrations in marine organisms were generally within allowable concentrations and pose no threat to public health. Likewise, studies suggested that levels of heavy metals in marine sediments are similar or lower compared to other regions. However, localized hotspots of chronic metal pollution in areas influenced by industrial facilities, desalination plants, and oil refineries have been reported. Holistic spatial and temporal monitoring and comprehensive national and regional strategies are critical to combat and manage heavy metal pollution in the Arabian Gulf.
Afficher plus [+] Moins [-]Use of remote sensing techniques and aeromagnetic data to study episodic oil seep discharges along the Gulf of Suez in Egypt Texte intégral
2013
Kaiser, M.F. | Aziz, A.M. | Ghieth, B.M.
Four successive oil discharges were observed during the last 2years following the recording of the earthquake events. Oil slicks were clearly observed in the thermal band of the Enhanced Thematic Mapper images acquired during the discharge events. Lineaments were extracted from the ETM+ image data and SRTM (DEM). The seismic activity is conformable in time and spatially related to active major faults and structural lineaments. The concerned site was subjected to a numerous earthquakes with magnitudes ranging from 3 to 5.4Mb. Aeromagnetic field data analyses indicated the existence of deep major faults crossing the Gebel El-Zeit and the Mellaha basins (oil reservoirs). The magnetic field survey showed major distinctive fault striking NE–SW at 7000m depth. Occurrence of these faults at great depth enables the crude oil to migrate upward and appear at the surfaces as oil seeps onshore and as offshore slicks in the Gemsa–Hurghada coastal zone.
Afficher plus [+] Moins [-]Variations of 210Po and 210Pb concentration in mussels (Mytilus galloprovincialis) from Didim and Izmir Bay (Turkish coast of Aegean Sea) Texte intégral
2013
Aközcan, S. | Uğur Görgün, A.
In this study, the activity concentrations of 210Po and 210Pb were determined in mussels (Mytilus galloprovincialis) collected from Didim and Izmir Bay (Turkish coast of Aegean Sea) during the period of April 2006–March 2007. The concentrations activity of 210Po were determined spectroscopically through its 5.30MeV alpha particle emission, using 209Po as an internal tracer. The 210Pb activity concentrations were determined from the ingrowth of 210Po, assuming zero initial 210Po activity. The results of 210Po and 210Pb activity concentrations were found to vary between 34±9 and 1855±98Bqkg−1 dry weight and ND (lower than limit of detection) – 64±6Bqkg−1 dry weight, respectively. 210Po/210Pb ratio ranged between 1.00 and 106.87. The highest 210Po activities were found in mussels collected from Didim.
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