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Titanium determination by multisyringe flow injection analysis system and a liquid waveguide capillary cell in solid and liquid environmental samples
2013
Sánchez-Quiles, David | Tovar-Sánchez, Antonio | Horstkotte, Burkhard
A multisyringe flow injection analysis system using a liquid waveguide capillary cell (MSFIA-LWCC) has been used for the spectrophotometric determination of titanium (Ti) in marine environmental samples. Samples were previous digested using potassium peroxodisulfate (K2S2O8). The method showed to be linear over a range up to 1μM with a detection limit of 9.2nM. The analysis consumes little reagent (250μL) and sample (600μL). It had an adequate accuracy with high repeatability (RSD of 1.8%) for all marine samples. The proposed method was used to evaluate the concentration of Ti in natural samples collected in the coastal area of the Majorca Island (Western Mediterranean Sea). We report average concentrations of Ti in coastal surface microlayer of 510.7±267.2nM, in surface sediments of 2.72±1.84μmol/g, and in rhizomes and leaves of Posidonia oceanica of 310±295nmol/g and 157±132nmol/g, respectively.
Afficher plus [+] Moins [-]Concentration and composition of polycyclic aromatic hydrocarbons (PAHs) in plastic pellets: Implications for small-scale diagnostic and environmental monitoring
2013
Fisner, Mara | Taniguchi, Satie | Majer, Alessandra P. | Bícego, Márcia C. | Turra, Alexander
Plastic pellets may serve as a carrier of toxic contaminants, including polycyclic aromatic hydrocarbons (PAHs). Considering that beach morphodynamics and pellet distribution varied along the shore, and that contaminant sources may vary on different scales, it is expected that this variability is reflected in the concentration and composition of contaminants. This hypothesis was tested through a sampling of plastic pellets at 30 sites along the shore in Santos Bay (Brazil). The total PAH concentrations and the priority PAHs showed high variability, with no clear pattern. Their composition differed among the sampling sites; some of the compounds represent a potential risk to organisms. The sources of contamination, as indicated by the isomer ratios, were also variable among sites. The high small-scale spatial variability found here has implications for estimating the plastic pellet contamination on beaches, since a sample from a single site is unlikely to be representative of an entire beach.
Afficher plus [+] Moins [-]Impacts of long-line aquaculture of Pacific oysters (Crassostrea gigas) on sulfate reduction and diffusive nutrient flux in the coastal sediments of Jinhae–Tongyeong, Korea
2013
Hyun, Jung-Ho | Kim, Sŭng-han | Mok, Jin-Sook | Lee, Jae-seong | An, Sung-Uk | Lee, Won-Chan | Jung, Rae-Hong
We investigated the environmental impacts of long-line aquaculture of Pacific oysters (Crassostrea gigas) on sediment geochemistry and carbon oxidation by sulfate reduction and diffusive benthic nutrient flux in a coastal ecosystem in Korea. Inventories of the NH4+ and HPO42- at the farm site were 7.7–11.5 and 1.8–8.0 times higher, respectively, than those at a reference site. Sulfate reduction rates (SRRs) at the oyster farm were 2.4–5.2 times higher than SRRs at the reference site. The SRRs at the farm site were responsible for 48–99% (average 70%) of the total C oxidation in the sediment. The diffusive benthic fluxes of NH4+ and HPO42- at the oyster farm were comparable to 30–164% and 19–58%, respectively, of the N and P demands for primary production, and were responsible for the enhanced benthic microalgal biomass on the surface sediment.
Afficher plus [+] Moins [-]Towards quantitative ecological risk assessment of elevated carbon dioxide levels in the marine environment
2013
de Vries, Pepijn | Tamis, Jacqueline E. | Foekema, Edwin M. | Klok, Chris | Murk, Albertinka J.
The environmental impact of elevated carbon dioxide (CO2) levels has become of more interest in recent years. This, in relation to globally rising CO2 levels and related considerations of geological CO2 storage as a mitigating measure. In the present study effect data from literature were collected in order to conduct a marine ecological risk assessment of elevated CO2 levels, using a Species Sensitivity Distribution (SSD). It became evident that information currently available from the literature is mostly insufficient for such a quantitative approach. Most studies focus on effects of expected future CO2 levels, testing only one or two elevated concentrations. A full dose-response relationship, a uniform measure of exposure, and standardized test protocols are essential for conducting a proper quantitative risk assessment of elevated CO2 levels. Improvements are proposed to make future tests more valuable and usable for quantitative risk assessment.
Afficher plus [+] Moins [-]Hypoxia induces abnormal larval development and affects biofilm–larval interaction in the serpulid polychaete Hydroides elegans
2013
Shin, P.K.S. | Leung, J.Y.S. | Qiu, J.W. | Ang, P.O. | Chiu, J.M.Y. | Thiyagarajan, V. | Cheung, S.G.
Hydroides elegans, a worldwide fouling polychaete, can spawn throughout the year, but its recruitment drops during summer when hypoxia prevails. Here, the influence of hypoxia on larval development and settlement of H. elegans was investigated. Results showed that larval development was compromised at 1mg O2 l−1 with a lower proportion of competent larvae and a higher proportion of malformed larvae, probably due to reduction in clearance rate. Regarding larval settlement, although most of the larvae were reluctant to settle at 1mg O2 l−1, regardless of the biofilm nature, they settled quickly within 24h in response to the resumption of dissolved oxygen. Furthermore, only about 5% of the larvae settled on the biofilms developed under hypoxia, regardless of dissolved oxygen levels of the seawater. The delayed larval development and potential alteration of biofilm nature owing to hypoxia explained why the recruitment of H. elegans declines during summer.
Afficher plus [+] Moins [-]Consequences of a simulated rapid ocean acidification event for benthic ecosystem processes and functions
2013
Murray, Fiona | Widdicombe, Stephen | McNeill, C Louise | Solan, Martin
Whilst the biological consequences of long-term, gradual changes in acidity associated with the oceanic uptake of atmospheric carbon dioxide (CO2) are increasingly studied, the potential effects of rapid acidification associated with a failure of sub-seabed carbon storage infrastructure have received less attention. This study investigates the effects of severe short-term (8days) exposure to acidified seawater on infaunal mediation of ecosystem processes (bioirrigation and sediment particle redistribution) and functioning (nutrient concentrations). Following acidification, individuals of Amphiura filiformis exhibited emergent behaviour typical of a stress response, which resulted in altered bioturbation, but limited changes in nutrient cycling. Under acidified conditions, A. filiformis moved to shallower depths within the sediment and the variability in occupancy depth reduced considerably. This study indicated that rapid acidification events may not be lethal to benthic invertebrates, but may result in behavioural changes that could have longer-term implications for species survival, ecosystem structure and functioning.
Afficher plus [+] Moins [-]Cadmium, copper and lead in macroalgae from the Veracruz Reef System, Gulf of Mexico: Spatial distribution and rainy season variability
2013
Horta-Puga, Guillermo | Cházaro-Olvera, Sergio | Winfield, Ignacio | Avila-Romero, Marisol | Moreno-Ramírez, Margarita
This study focused on the spatial distribution of trace metals in the Veracruz Reef System in the Southern Gulf of Mexico, and its variability in the early (July) and late (September) rainy season of 2008, by analyzing the concentration of Cd, Cu and Pb in benthic macroalgae. Mean concentrations are lower (Pb 295±347ngg−1, Cd 17.9±15.0ngg−1), or similar (Cu 3.4±4.5μgg−1) to those reported from other coastal areas. Cd and Pb concentrations are influenced by the discharge of the Jamapa River, evidencing a fluvial control on coastal trace metal levels. Also, Cd and Cu concentrations were lower in the late rainy season, when there is a high load of suspended sediments derived from fluvial discharge, which probably adsorb dissolved metals decreasing their bioavailability. Pb concentrations have been decreasing in the last two decades in the SGM, after the banning of leaded-gasoline in the late 20th century.
Afficher plus [+] Moins [-]Anthropogenic marine debris in the coastal environment: A multi-year comparison between coastal waters and local shores
2013
Anthropogenic marine debris (AMD) is frequently studied on sandy beaches and occasionally in coastal waters, but links between these two environments have rarely been studied. High densities of AMD were found in coastal waters and on local shores of a large bay system in northern-central Chile. No seasonal pattern in AMD densities was found, but there was a trend of increasing densities over the entire study period. While plastics and Styrofoam were the most common types of AMD both on shores and in coastal waters, AMD composition differed slightly between the two environments. The results suggest that AMD from coastal waters are deposited on local shores, which over time accumulate all types of AMD. The types and the very low percentages of AMD with epibionts point to mostly local sources. Based on these results, it can be concluded that a reduction of AMD will require local solutions.
Afficher plus [+] Moins [-]Biodegradation of low-density polyethylene by marine bacteria from pelagic waters, Arabian Sea, India
2013
Harshvardhan, Kumar | Jha, Bhavanath
Sixty marine bacteria isolated from pelagic waters were screened for their ability to degrade low-density polyethylene; among them, three were positive and able to grow in a medium containing polythene as the sole carbon source. The positive isolates were identified as Kocuria palustris M16, Bacillus pumilus M27 and Bacillus subtilis H1584 based on the 16S rRNA gene sequence homology. The weight loss of polyethylene was 1%, 1.5% and 1.75% after 30days of incubation with the M16, M27 and H1584 isolates, respectively. The maximum (32%) cell surface hydrophobicity was observed in M16, followed by the H1584 and M27 isolates. The viability of the isolates growing on the polyethylene surface was confirmed using a triphenyltetrazolium chloride reduction test. The viability was also correlated with a concomitant increase in the protein density of the biomass. Polyethylene biodegradation was further confirmed by an increase in the Keto Carbonyl Bond Index, the Ester Carbonyl Bond Index and the Vinyl Bond Index, which were calculated from FT-IR spectra.
Afficher plus [+] Moins [-]Sublethal effects of a chlorinated and heated effluent on the physiology of the mussel, Mytilus edulis L.: A reduction in fitness for survival?
2013
(Krysia),
Coastal power stations entrain large volumes of cooling water, requiring biocidal treatment to prevent biological fouling. Discharged effluent is both heated and contaminated with residual traces of biocide and so it is necessary to quantify the impacts of this discharge. Cooling water from Heysham 2 nuclear power station, NW England, UK, is discharged to the intertidal area, via a culvert (to minimise erosion and maximise dilution and dispersion by directing the effluent into the receiving water at all states of the tide) within which the effluent is contained at low water. The culvert and surrounding coastal area support a population of blue mussels (Mytilus edulis). Mussel health was determined along a gradient of exposure, using three physiological indices: Scope for Growth, Gonad Mantle Index and Somatic Condition Index (K Factor). The Mussels within the culvert exhibited reduced physiological index values compared to an external site. A trend was identified down the length of the culvert, representing a gradient of exposure and indicating a potential negative effect on growth and reproductive output.
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