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Coral microbial community dynamics in response to anthropogenic impacts near a major city in the central Red Sea 全文
2016
Ziegler, Maren | Roik, Anna | Porter, Adam | Zubier, Khalid | Mudarris, Mohammed S. | Ormond, Rupert | Voolstra, Christian R.
Coral-associated bacteria play an increasingly recognized part in coral health. We investigated the effect of local anthropogenic impacts on coral microbial communities on reefs near Jeddah, the largest city on the Saudi Arabian coast of the central Red Sea. We analyzed the bacterial community structure of water and corals (Pocillopora verrucosa and Acropora hemprichii) at sites that were relatively unimpacted, exposed to sedimentation & local sewage, or in the discharge area of municipal wastewaters. Coral microbial communities were significantly different at impacted sites: in both corals the main symbiotic taxon decreased in abundance. In contrast, opportunistic bacterial families, such as e.g. Vibrionaceae and Rhodobacteraceae, were more abundant in corals at impacted sites. In conclusion, microbial community response revealed a measurable footprint of anthropogenic impacts to coral ecosystems close to Jeddah, even though the corals appeared visually healthy.
显示更多 [+] 显示较少 [-]Chemical characterization of atmospheric particulate matter and their source apportionment at an emerging industrial coastal city, Visakhapatnam, India 全文
2016
Police, Sandeep | Sahu, Sanjay Kumar | Pandit, Gauri Girish
In the present study, particulate matter (PM10) was collected from two different locations viz. Jogannapalem and Parawada sites of Visakhapatnam. During study period, PM10 concentrations were found in the range from 34.8 to 109.7 μg/m3 and from 32.3 to 137.3 μg/m3 at Jogannapalem and Parawada sites respectively. Chemical characterization of PM10 was carried out to estimate the concentration levels of various particle bound chemical species (Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Pb, Cd, Cl−, F-, NO3-, SO42−, Na+, K+, Mg2+ and Ca2+). Among different species, Al was observed to have highest average concentration (4.1 μg/m3 at Jogannapalem and 3.8 μg/m3 at Parawada) at both the sampling sites followed by K at Jogannapalem and Ca at Parawada. PM10 concentration as well as trace metals concentration (except Mn and Fe) was observed to have higher concentrations at Parawada site as compared to Jogannapalem site, indicating higher pollution at Parawada.Source apportionment study carried out using PMF (USEPA PMF5.0) receptor model identified six major sources at Jogannapalem and seven predominant sources at Parawada, which are contributing to collected PM. The two study locations share five common sources viz. crustal, sea salt spray, coal combustion, fuel oil combustion and metal industry. The other sources include biomass burning at Jogannapalem; road traffic and secondary aerosols at Parawada. At Jogannapalem, biomass burning (35%) is the predominant source, whereas coal combustion (22.6%) is dominating at Parawada. PMF factor profiles were observed to have similar elemental profiles obtained at different industrial locations of Visakhapatnam.
显示更多 [+] 显示较少 [-]Feeding type affects microplastic ingestion in a coastal invertebrate community 全文
2016
Setälä, Outi | Norkko, Joanna | Lehtiniemi, Maiju
Marine litter is one of the problems marine ecosystems face at present, coastal habitats and food webs being the most vulnerable as they are closest to the sources of litter. A range of animals (bivalves, free swimming crustaceans and benthic, deposit-feeding animals), of a coastal community of the northern Baltic Sea were exposed to relatively low concentrations of 10μm microbeads. The experiment was carried out as a small scale mesocosm study to mimic natural habitat. The beads were ingested by all animals in all experimental concentrations (5, 50 and 250beadsmL−1). Bivalves (Mytilus trossulus, Macoma balthica) contained significantly higher amounts of beads compared with the other groups. Free-swimming crustaceans ingested more beads compared with the benthic animals that were feeding only on the sediment surface. Ingestion of the beads was concluded to be the result of particle concentration, feeding mode and the encounter rate in a patchy environment.
显示更多 [+] 显示较少 [-]From blue to black: Anthropogenic forcing of carbon and nitrogen influx to mangrove-lined estuaries in the South China Sea 全文
2016
Lee, S.Y.
Southeast Asia is the global centre of mangrove development but human activities have dramatically reduced mangrove area in the region. An analysis is made of the shift in carbon and nitrogen influxes into the South China Sea (SCS) resulting from three anthropogenic nutrient sources: domestic sewage discharge, fertilizer use in rice agriculture and environmental loss from mariculture, between 1997 and 2010. Anthropogenic C and N influxes were, respectively, 1.81× and 1.43× those in 1997, with coastal aquaculture contributing most to the increase. In contrast, fringing mangroves provided ~44% of the C but only ~3% of the N from anthropogenic sources in 2010. In 1997, influx from mangroves was 113% and 6% of anthropogenic influx for C and N, respectively. This dominance by relatively labile anthropogenic nutrients over mangrove sources would change nearshore trophodynamics, with negative implications for the resilience of mangroves and nutrient-intolerant systems such as corals.
显示更多 [+] 显示较少 [-]Photo-enhanced toxicity of two weathered Macondo crude oils to early life stages of the eastern oyster (Crassostrea virginica) 全文
2016
Polycyclic aromatic hydrocarbons (PAHs) have been reported to absorb ultraviolet (UV) light, resulting in enhanced toxicity. Early developmental stages of bivalves may be particularly susceptible to photo-enhanced toxicity during oil spills. In the current study, toxicity tests were conducted with sperm and three larval ages of the eastern oyster (Crassostrea virginica) to evaluate the photo-enhanced toxicity of low-energy water-accommodated fractions (WAFs) of two weathered Macondo crude oils collected from the Deepwater Horizon incident. Larvae exposed to oil WAFs under UV-filtered light demonstrated consistently higher survival and normal development than larvae exposed to WAFs under UV light. The phototoxicity of weathered Macondo oil increased as a function of increasing UV light intensity and dose. Early developing oyster larvae were the most sensitive to photo-enhanced toxicity, whereas later shelled prodissoconch larvae were insensitive. Comparisons between two weathered crude oils demonstrated that toxicity was dependent on phototoxic PAH concentration and UV light intensity.
显示更多 [+] 显示较少 [-]A comparative proteomic study on the effects of metal pollution in oysters Crassostrea hongkongensis 全文
2016
The metal pollution has posed great risk on the coastal organisms along the Jiulongjiang Estuary in South China. In this work, two-dimensional electrophoresis-based proteomics was applied to the oysters Crassostrea hongkongensis from metal pollution sites to characterize the proteomic responses to metal pollution. Metal accumulation and proteomic responses indicated that the oysters from BJ site were more severely contaminated than those from FG site. Compared with those oyster samples from the clean site (JZ), metal pollution induced cellular injuries, oxidative and immune stresses in oyster heapatopancreas from both BJ and FG sites via differential metabolic pathways. In addition, metal pollution in BJ site induced disturbance in energy and lipid metabolisms in oysters. Results indicated that cathepsin L and ferritin GF1 might be the biomarkers of As and Fe in oyster C. hongkongensis, respectively. This study demonstrates that proteomics is a useful tool for investigating biological effects induced by metal pollution.
显示更多 [+] 显示较少 [-]Sediment chemistry and toxicity in Barnegat Bay, New Jersey: Pre- and post-Hurricane Sandy, 2012–13 全文
2016
Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.
显示更多 [+] 显示较少 [-]Geographical and temporal variation of E. coli and norovirus in mussels 全文
2016
Bivalve shellfish may accumulate contaminants of public health concern including pathogenic bacteria and viruses. Microbiological monitoring of production areas is based on faecal coliforms in water in the USA and Escherichia coli in bivalve molluscs in the European Union. E. coli is known to reflect contamination with Salmonella enterica but not necessarily with other human pathogens such as enteric viruses. A structured field study was undertaken at three locations in order to investigate the geographical and temporal variability of E. coli and norovirus (NoV). Total norovirus concentration differed significantly by both sampling site and sampling date. A significant correlation was found between total NoV concentration and E. coli concentration by sample, but not with E. coli in seawater. The results have implications for the establishment of sampling plans for NoV in harvesting areas and potentially also for the approach taken to classification based on faecal indicator bacteria.
显示更多 [+] 显示较少 [-]De- facto marine protection from a Navy bombing range: Farallon De Medinilla, Mariana Archipelago, 1997 to 2012 全文
2016
Smith, Stephen H. | Marx, Donald E.
Fourteen surveys were conducted at Farallon De Medinilla (a U.S. Department of Defense bombing range in the Mariana Archipelago) between 1997 and 2012; annual surveys were conducted from 1999 through 2012. There was no evidence that the condition of the biological resources assessed had changed, or been adversely impacted to a significant degree by the training activities being conducted there. Restricted access has resulted in a de-facto preserve effect and outweighs minor negative impacts from training. The health, abundance and biomass of fishes, corals and other marine resources are comparable to or superior to those in similar habitats at other locations within the Mariana Archipelago. Our research suggests that the greatest threat to FDM's marine resources is from fishermen, not military training activities.
显示更多 [+] 显示较少 [-]Does Black Carbon Contribute to Eutrophication in Large Lakes? 全文
2016
Odhiambo, Moses | Routh, Joyanto
Eutrophication is a major ecological crisis in water bodies. This is mainly driven by anthropogenic activities in the catchment that incorporate various nutrients. Input of nutrients can also be driven by atmospheric deposition, which has a large footprint that goes beyond local point source(s). In particular, black carbon (BC) can be a carrier of various nutrients and increase primary productivity in lakes. We need to monitor the input of BC in large water bodies to fully understand its role in driving primary productivity and change in trophic status.
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