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Ecology of twelve species of Thyasiridae (Mollusca: Bivalvia)
2011
Keuning, Rozemarijn | Schander, Christoffer | Kongsrud, Jon Anders | Willassen, Endre
Benthic samples from coastal locations off Southwestern Norway were examined and the specimens of Thyasiridae were identified to species. A multivariate analysis based on 13 parameters was carried out and the environmental preferences of all thyasirid species present were determined. The potential of the Thyasiridae as indicators of organic enrichment was investigated by using direct canonical correspondence analyses to identify correlations between selected environmental parameters and the collected biological data. The presence of Thyasira sarsi together with a low biodiversity is a good indicator of organic enrichment. High thyasirid species diversity seems to indicate good environmental conditions, and single thyasirid species that lack symbiotic bacteria might also be useful as indicators of good environmental conditions.
Show more [+] Less [-]Organic and inorganic matter in Louisiana coastal waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi regions
2011
Schaeffer, Blake A. | Conmy, Robyn N. | Aukamp, Jessica | Craven, George | Ferer, Erin J.
Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi River locations, in 2007–2008. The range of CDOM was 0.092m⁻¹ at Barataria in June 2008 to 11.225m⁻¹ at Mississippi in February 2008. An indicator of organic matter quality was predicted by the spectral slope of absorption coefficients from 350 to 412nm which was between 0.0087m⁻¹ at Mississippi in May 2008 and 0.0261m⁻¹ at Barataria in June 2008. CDOM was the dominant component of light attenuation at Terrebonne and Barataria. Detritus and CDOM were the primary components of light attenuation at Vermilion, Atchafalaya, and Mississippi. DOC ranged between 65 and 1235μM. PIM ranged between 1.1 and 426.3mgL⁻¹ and POM was between 0.3 and 49.6mgL⁻¹.
Show more [+] Less [-]Distribution and source differentiation of PAHs and PCBs among size and density fractions in contaminated harbor sediment particles and their implications in toxicological assessment
2011
Huang, Yun-Jie | Lee, Chon-Lin | Fang, Meng-Der
Sediment samples collected from Kaohsiung Harbor (Taiwan) were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) and 118 individual polychlorinated biphenyl (PCB) congeners in various particle size fractions and two density fractions. The PAHs in the low density fraction were a much more sensitive and effective indicator of the PAH source than those in the sediment as a whole. Hierarchical cluster analysis of PAH analytes in the low density sediments revealed significant differences in compositional patterns between locations and among size fractions. In the sediment samples from both study sites, the low density fraction particles had up to 155 and 150 times higher concentrations of PAHs and PCBs, respectively, than those in the corresponding high density fractions. In addition, the total toxic benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzodioxin (TCDD, dioxin) equivalents in the sediment low density fractions were much higher (up to 170 and 273 times, respectively) than the corresponding high density fractions.
Show more [+] Less [-]Hindcast of oil-spill pollution during the Lebanon crisis in the Eastern Mediterranean, July–August 2006
2011
Coppini, Giovanni | De Dominicis, Michela | Zodiatis, George | Lardner, Robin | Pinardi, Nadia | Santoleri, Rosalia | Colella, Simone | Bignami, Francesco | Hayes, Daniel R. | Soloviev, Dmitry | Georgiou, Georgios | Kallos, George
MOON (Mediterranean Operational Oceanography Network http://www.moon-oceanforecasting.eu) provides near-real-time information on oil-spill detection (ocean color and SAR) and predictions [ocean forecasts (MFS and CYCOFOS) and oil-spill predictions (MEDSLIK)]. We employ this system to study the Lebanese oil-pollution crisis in summer 2006 and thus to assist regional and local decision makers in Europe, regionally and locally. The MEDSLIK oil-spill predictions obtained using CYCOFOS high-resolution ocean fields are compared with those obtained using lower-resolution MFS hydrodynamics, and both are validated against satellite observations. The predicted beached oil distributions along the Lebanese and Syrian coasts are compared with in situ observations. The oil-spill predictions are able to simulate the northward movement of the oil spill, with the CYCOFOS predictions being in better agreement with satellite observations. Among the free MEDSLIK parameters tested in the sensitivity experiments, the drift factor appears to be the most relevant to improve the quality of the results.
Show more [+] Less [-]Early microbial biofilm formation on marine plastic debris
2011
Lobelle, Delphine | Cunliffe, Michael
An important aspect of the global problem of plastic debris pollution is plastic buoyancy. There is some evidence that buoyancy is influenced by attached biofilms but as yet this is poorly understood. We submerged polyethylene plastic in seawater and sampled weekly for 3weeks in order to study early stage processes. Microbial biofilms developed rapidly on the plastic and coincided with significant changes in the physicochemical properties of the plastic. Submerged plastic became less hydrophobic and more neutrally buoyant during the experiment. Bacteria readily colonised the plastic but there was no indication that plastic-degrading microorganisms were present. This study contributes to improved understanding of the fate of plastic debris in the marine environment.
Show more [+] Less [-]The effect of thermal pollution on benthic foraminiferal assemblages in the Mediterranean shoreface adjacent to Hadera power plant (Israel)
2011
Arieli, Ruthie Nina | Almogi-Labin, Ahuva | Abramovich, Sigal | Herut, Barak
The thermal pollution patch of Hadera power plant was used as a natural laboratory to evaluate the potential long-term effects of rise in Eastern Mediterranean SST on living benthic foraminifera. Their sensitivity to environmental changes makes foraminifera ideal for this study. Ten monthly sampling campaigns were performed in four stations located along a temperature gradient up to 10°C from the discharge site of heated seawater to a control station. The SST along this transect varied between 25/18°C in winter and 36/31°C in summer. A significant negative correlation was found between SST in all stations and benthic foraminiferal abundance, species richness and diversity. The total foraminiferal abundance and species richness was particularly low at the thermally polluted stations especially during summer when SST exceeded 30°C, but also throughout the entire year. This indicates that thermal pollution has a detrimental effect on benthic foraminifera, irrelevant to the natural seasonal changes in SST.
Show more [+] Less [-]Macroalgal diversity along the Baltic Sea salinity gradient challenges Remane’s species-minimum concept
2011
Schubert, Hendrik | Feuerpfeil, Peter | Marquardt, Ronny | Telesh, Irena | Skarlato, Sergei
Remane’s species-minimum concept, which states that the lowest number of taxa occurs at the horohalinicum (5–8psu), was tested by investigating macroalgal diversity on hard substrates along the natural salinity gradient in the Baltic Sea. Field data on species occurrence and abundance were collected by SCUBA diving along 10 transects of the Finnish, Swedish and German coasts, covering a salinity range from 3.9 to 27psu. Macroalgal species numbers declined steadily with salinity, decreasing until 7.2psu was reached, but in the horohalinicum, a marked reduction of species number and a change in diversity were indicated by the Shannon index and evenness values. The non-linear decrease in macroalgal diversity at 5–8psu and the lack of increase in species numbers at salinities below 5psu imply a restricted applicability of Remane’s species-minimum concept to macroalgae.
Show more [+] Less [-]Hydrocarbon composition and distribution in a coastal region under influence of oil production in northeast Brazil
2011
Wagener, Angela de L.R. | Carreira, Renato S. | Hamacher, Claudia | Scofield, Arthur de L. | Farias, Cassia O. | Cordeiro, Lívia G.M.S. | Luz, Letícia G. | Baêta, Aída P. | Kalas, Francine A.
Waters and sediments from the Potiguar Basin (NE Brazilian coast) were investigated for the presence and nature of polycyclic aromatic hydrocarbons (PAH) and aliphatic hydrocarbons. The region receives treated produced waters through a submarine outfall system serving the industrial district. The total dispersed/dissolved concentrations in the water column ranged from 10–50ngL⁻¹ for ∑16PAH and 5–10μgL⁻¹ for total aliphatic hydrocarbons. In the sediments, hydrocarbon concentrations were low (0.5–10ngg⁻¹for ∑16PAH and 0.01–5.0μgg⁻¹ for total aliphatic hydrocarbons) and were consistent with the low organic carbon content of the local sandy sediments. These data indicate little and/or absence of anthropogenic influence on hydrocarbon distribution in water and sediment. Therefore, the measured values may be taken as background values for the region and can be used as future reference following new developments of the petroleum industry in the Potiguar Basin.
Show more [+] Less [-]Heavy metal concentrations and biomarkers of oxidative stress in native mussels (Mytilus edulis chilensis) from Beagle Channel coast (Tierra del Fuego, Argentina)
2011
Duarte, Claudia A. | Giarratano, Erica | Amin, Oscar A. | Comoglio, Laura I.
The aim of this study was to evaluate the usefulness of oxidative stress biomarkers of pollution in native mussels Mytilus edulis chilensis from the Beagle Channel. Spatial and seasonal variations of catalase, glutathione-S-transferase and lipid peroxidation in gills and digestive gland were analyzed in relation to environmental parameters, heavy metals in sediment and in tissue. Four sites with anthropogenic impact and a control site were selected and monitored during the four seasons of 2007. We found significant differences among sites in concentrations of dissolved nutrients and heavy metals in sediments, with the highest values recorded at sites with anthropogenic pressure. Different patterns were observed between concentrations of metals in tissues and in sediments suggesting differences in bioavailability. There were also significant differences in biomarker responses among sites, despite the strong seasonal variability. Our results showed relatively moderate levels of pollution in the study area as a result of urban influences.
Show more [+] Less [-]Sorption behavior of phenanthrene in Yangtze estuarine sediments: Sequential separation
2011
Yang, Yi | Liu, Min | Wang, Lili | Fu, Jialu | Yan, Caixia | Zhou, John L.
In the present study, phenanthrene was chosen as the probe compound for determining the sorption of PAHs in sediments from Yangtze estuary and nearby coastal area, China. Sorption isotherms were fitted well by the Freundlich and dual models, respectively. Selected sediments were further sequentially separated to remove the carbonate and organic carbon (OC). Calculated OC sorption capacity values based on both H₂O₂ oxidization and 375°C combustion methods were similar and comparable to the Kₒc values estimated by the empirical linear sorption equations. Both sorption models and sorption data using sequentially separated samples achieve the similar conclusions: (1) the partition behavior dominated by OC in sediments with fₒc>0.01; (2) for sediments with 0.001<fₒc<0.01, OC dominated sorption at relatively high aqueous concentration; whereas mineral phase adsorption dominated sorption at lower concentration especially when Cw/Sw was in the range of 0.0001–0.001 in natural aqueous system.
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