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²¹⁰Po and ²¹⁰Pb variations in fish species from the Aegean Sea and the contribution of ²¹⁰Po to the radiation dose Full text
2012
Mat Çatal, Ebru | Uğur, Aysun | Özden, Banu | Filizok, Işık
In recent years, there has been increasing interest in the significance of natural radionuclides, particularly ²¹⁰Po, in the marine environment. ²¹⁰Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for ²¹⁰Po and ²¹⁰Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their ²¹⁰Po and ²¹⁰Pb content. The ²¹⁰Po and ²¹⁰Pb concentrations in the fish samples were found to vary from undetectable levels to 499±44Bqkg⁻¹ dry weight (dw) and from 1.0±0.3Bqkg⁻¹ to 35±4.0Bqkg⁻¹ (dw), respectively. There were no significant differences in the activity concentrations of ²¹⁰Po and ²¹⁰Pb in fish samples between seasons (ANOVA, P>0.05). The highest dose contribution of ²¹⁰Po to humans was calculated to be 10,530μSvyear⁻¹.
Show more [+] Less [-]Island shadow effects and the wave climate of the Western Tuamotu Archipelago (French Polynesia) inferred from altimetry and numerical model data Full text
2012
Andréfouët, Serge | Ardhuin, Fabrice | Queffeulou, Pierre | Le Gendre, Romain
To implement a numerical model of atoll lagoon circulation, we characterized first the significant wave height (Hs) regime of the Western Tuamotu Archipelago and the local attenuation due to the protection offered by large atolls in the south Tuamotu. Altimetry satellite data and a WAVEWATCH III two-way nested wave model at 5km resolution from 2000 to 2010 were used. Correlation between altimetry and model was high (0.88) over the period. According to the wave model, the archipelago inner seas experienced attenuated Hs year-long with a yearly average Hs around 1.3m vs a minimum of 1.6m elsewhere. The island shadow effect is especially significant in the austral winter. In contrast with southern atolls, Western Tuamotu experienced only few days per year of Hs larger than 2.5m generated by very high Hs southern swell, transient western local storms, strong easterly winds, and during the passage of distant hurricanes.
Show more [+] Less [-]Environmental factors responsible for the incidence of antibiotic resistance genes in pristine Crassostrea virginica reefs Full text
2012
Barkovskii, Andrei L. | Thomas, Michael | Hurley, Dorset | Teems, Clifford
The occurrence of tetracycline resistance (TRG) and integrase (INT) genes were monitored in Crassostrea virginica oyster reefs of three pristine creeks (SINERR, Georgia, USA). Their profiles revealed 85% similarity with the TRG/INT profiles observed in the adjacent to the SINERR and contaminated Altamaha River estuary (Barkovskii et al., 2010). The TRG/INT spectra and incidence frequencies corresponded to the source of oceanic input and to run-offs from creeks’ watersheds. The highest incidence frequencies and concentrations were observed in oysters. TRG/INT incidences correlated positively (Spearman Rank=0.88), and negatively correlated (−0.63 to −0.79) with creek salinity, conductivity, dissolved solids, and temperature. Coliform incidence positively correlated with temperature, and not with the TRG/INT incidence. The Altamaha River estuary was the primary TRG/INT source for the reefs with contributions from creek’s watersheds. TRG/INT were carried by non-coliforms with a preference for low-to-temperate thermohaline environments coupled with bioaccumulation by oysters.
Show more [+] Less [-]Effects of prolonged entanglement in discarded fishing gear with substantive biofouling on the health and behavior of an adult shortfin mako shark, Isurus oxyrinchus Full text
2012
Wegner, Nicholas C. | Cartamil, Daniel P.
A mature male shortfin mako, Isurus oxyrinchus, was captured with a three-strand twisted natural fiber rope wrapped around the body causing deep abrasions, scoliosis of the back, and undernourishment. Fifty-two pelagic peduculate barnacles from four species were found fouling on the rope. Assuming larval settlement occurred following entanglement, barnacle growth-rate data suggest the rope had been around the shark for at least 150days. However, the onset of severe scoliosis (likely linked to the increased constriction of the rope with growth and the added drag induced by biofouling) indicates that this rope may have been in place much longer. Following removal of the rope, a pop-up satellite archival tag was attached to the shark to assess post-release health. The resulting 54days of tag deployment data show that despite its injuries, the shark survived, and following an initial stress period, exhibited movement patterns characteristic of healthy makos.
Show more [+] Less [-]Radionuclide monitoring in molluscs inhabiting intertidal region near a nuclear installation, Gulf of Mannar, India Full text
2012
Feroz Khan, M. | Godwin Wesley, S.
Protection of non-human biota from ionizing contaminants, especially in the vicinity of nuclear installations is a very important aspect for nuclear engineers and ecologists. In this view, a baseline data on the activity concentration of ²¹⁰Po and ²¹⁰Pb were quantified in different tissues of molluscs inhabiting the intertidal region along the coast of Kudankulam. The activity concentration was noticed higher in the organs associated with digestion and metabolism. Filter feeding bivalve molluscs registered the maximum activity of ²¹⁰Po in their whole body compared to grazing gastropods. ²¹⁰Po:²¹⁰Pb ratio was calculated to be greater than unity in most of the analysed tissues. The ecological sensitivity of molluscs to the radiation exposure and the safeness of the environment was analysed by calculating the external and internal dose rate. The hazard quotient for molluscs was lesser than the global bench mark dose rate of 10μGyh–¹.
Show more [+] Less [-]Geochemistry of the northern Cyprus (NE Mediterranean) shelf sediments: Implications for anthropogenic and lithogenic impact Full text
2012
Duman, Muhammet | Kucuksezgin, Filiz | Atalar, Muge | Akcali, Baris
The concentrations of heavy metals and organic carbon in sediment were determined to evaluate spatial distributions from the three different regions of Cilician basin (Eastern Mediterranean) in 2011. The ranges of Cu, Pb, Zn, Ni, Co, Mn, Cr, As, Fe and organic carbon contents of sediments from the study area were 1.6–74, 1.6–9.2, 5.0–78, 6.6–114, 1.6–17, 141–1241, 9.0–46, 3.3–55.4, 1800–84400mgkg⁻¹ and 0.99–1.66%, respectively. The concentrations of Pb, Zn, Co, Cr, Al were lower than those average crustal values, which indicated that there were no major sources of pollution for these elements. The results showed that the sediments of northern, eastern and western shelf were polluted with As, Ni and Mn, As and Cu, Fe, respectively. The contamination factor of Cu in the western and As were found to be of moderate contamination in the eastern and northern parts of the study area. Metal levels were evaluated in sediments in accordance with the numerical SQG of the USEPA.
Show more [+] Less [-]Use of species sensitivity distributions to predict no-effect concentrations of an antifouling biocide, pyridine triphenylborane, for marine organisms Full text
2012
Mochida, Kazuhiko | Onduka, Toshimitsu | Amano, Haruna | Ito, Mana | Ito, Katsutoshi | Tanaka, Hiroyuki | Fujii, Kazunori
We used species sensitivity distributions (SSDs) and a Bayesian statistical model to carry out a primary risk assessment for pyridine triphenylborane (PTPB) in Hiroshima Bay, Japan. We used SSDs derived from toxicity values, such as EC₅₀ and LC₅₀, obtained from this study and previous work to calculate hazardous concentrations that should protect 95% and 99% of species (HC₅ and HC₁) and demonstrated that the medians of the HC₅ and HC₁ were 0.78 and 0.17μg/L, respectively. We also used liquid chromatography/mass spectrometry to investigate the occurrence of PTPB in seawater from several coastal sites of Hiroshima Bay and detected PTPB at concentrations of 4.8–21pg/L. Comparison of environmental concentrations to the HC values suggests that the current ecological risk posed by PTPB in Hiroshima Bay is low. This is the first report of the detection of PTPB in the natural marine environment.
Show more [+] Less [-]Evaluation of spatial and temporal variations of inorganic nutrient species in the eastern Aegean Sea waters Full text
2012
Aydin-Onen, Sinem | Kocak, Ferah | Kucuksezgin, Filiz
In this study, the state of the five stations’ quality was assessed on the basis of determination of temporal and spatial variability of nutrients with physicochemical variables. Besides this, organic matter of sediment, secchi disc depth and suspended solids were also determined. The samples were collected seasonally from different areas such as harbor and important touristic marinas along the eastern Aegean during June 2008–2009. As a result, the nutrients ranged between NH₄: 0.10–25.6, NO₂: 0.01–1.5, NO₃: 0.19–7.0, o.PO₄: 0.17–6.8, TPO₄: 0.32–9.6 and Si: 0.30–13.8μM, respectively. Precipitation leads to large changes in temperature, salinity, dissolved oxygen and nutrients. The highest nutrient values in this study were observed during the rainy season except o.PO₄-P and TPO₄-P. However, the physico-chemical variables have exhibited considerable temporal variations while nutrients showed spatial differences. The relatively high nutrient increase in the sampling stations coupled with surface runoff events during rainy period and pollution arising from both point and non-point sources.
Show more [+] Less [-]Bloom forming and toxic phytoplankton in transitional and coastal waters of Cantabria region coast (Southeastern Bay of Biscay, Spain) Full text
2012
Seoane, Sergio | Puente, Araceli | Guinda, Xabier | Juanes, Jose Antonio
Phytoplankton monitoring has extended to practically all the regions of the European coast due to the implementation of the European Water Framework Directive. In this way, the study of phytoplankton taxonomic composition and dynamic is being performed in many areas poorly studied or not studied before. During the last years, a monitoring programme has been carried out at the coast of Cantabria region (SE Bay of Biscay); the presence of some potentially toxic and bloom forming species (>7.5×10⁵cells per litre) has been observed. Diatoms and cryptophytes are the main blooming taxa in this region in the majority of the estuaries and in some of the coastal sites. All estuaries and coastal stations showed at least one potentially toxic species, being the dinoflagellates the group with the highest number of taxa observed. The potentially toxic species found in highest concentrations were the genera Pseudo-nitzschia and Chrysochromulina.
Show more [+] Less [-]Sewage organic markers in surface sediments around the Brazilian Antarctic station: Results from the 2009/10 austral summer and historical tendencies Full text
2012
Martins, César C. | Aguiar, Sabrina Nart | Bícego, Márcia C. | Montone, Rosalinda C.
The discharge of sewage into the Antarctic marine environments by scientific stations has resulted in local changes in these pristine sites. To assess the distribution and concentration of sewage indicators from the Brazilian Antarctic station, sediments were sampled during the 2009/10 austral summer at four points (water depth of 20 and 60m). Concentrations of faecal sterols and linear alkylbenzenes (LABs) ranged from <0.01 to 0.17μgg⁻¹ and <1.0 to 46.5ngg⁻¹ dry weight, respectively. Maximum concentration of faecal sterols was similar to the value previously calculated as the background level for this area (0.19μgg⁻¹), and it is lower than the concentration observed in previous studies (1997–2008), whereas the LABs concentrations remained practically constant (35ngg⁻¹). Despite the low concentrations of sewage markers, the permanent human activities in the region require monitoring programs to determine continuing trends and prevent the increase of anthropogenic impacts.
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