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Spatial–temporal variations and diversity of the bacterioplankton communities in the coastal waters of Kuwait Full text
2015
Almutairi, Awatef
The dynamics and composition of the bacterial community in the coastal waters of Kuwait are poorly understood. In this study, the spatial–temporal variations in the bacterial composition in the surface water along the Kuwaiti coast was examined by 16S rRNA denaturing gradient gel electrophoresis (DGGE) fingerprinting and phylogeny analyses. The sampling sites were Kuwait Bay, Al-Sabbiya (north of the bay) and Al-Khairan (to the south). The bacterial composition was more variable in the summer for all sites. A cluster analysis of the DGGE fingerprint revealed two main clusters, indicating a temporal similarity between sites. Kuwait Bay and Al-Khairan were more similar to each other than to Al-Sabbiya. The bacterial community composition exhibited distinctive spatial variations, with more diversity at Al-Khairan and less diversity at Al-Sabbiya. At all sites, the dominant bacteria were Alphaproteobacteria, in particular Rhodobacteraceae, followed by Alteromonadaceae (Gammaproteobacteria) and Bacteroidetes.
Show more [+] Less [-]Organophosphorus flame retardants (PFRs) and plasticisers in harbour porpoises (Phocoena phocoena) stranded or bycaught in the UK during 2012 Full text
2015
Papachlimitzou, Alexandra | Barber, Jonathan L. | Losada, Sara | Bersuder, Philippe | Deaville, Rob | Brownlow, Andrew | Penrose, Rod | Jepson, Paul D. | Law, Robin J.
A suite of twenty organophosphorus flame retardant compounds have been determined in blubber and liver tissue of twenty harbour porpoises stranded or bycaught in the UK during 2012 in order to establish current levels of contamination. Fourteen of the twenty compounds were below the limits of quantification in all samples. Six could be quantified at maximum concentrations (in blubber) between 6.7 and 246μgkg−1 wet weight. These levels do not suggest a high level of concern regarding potential impacts and do not indicate that routine monitoring in UK porpoises is warranted at this time.
Show more [+] Less [-]Physiological perturbations in juvenile cuttlefish Sepia officinalis induced by subchronic exposure to dissolved zinc Full text
2015
Le Pabic, Charles | Caplat, Christelle | Lehodey, Jean-Paul | Dallas, Lorna | Koueta, N. (Noussithé)
Although cephalopod early life stage development often occurs in coastal areas where contamination is real and continuous, the physiological perturbations induced by contaminants have been rarely investigated. This study focused on the Zn as it is one of the trace metals the most concentrated in coastal waters, worldwide. As Zn-tolerance limits were unknown in juvenile Sepia officinalis, the aim of this study was to estimate the threshold inducing mortality during the 2-first weeks post-hatching, and to determine its sensitivity using digestive and immune enzymatic assays, as well as growth and behavior follow-up during the first 5weeks post-hatching. Our study highlighted a Zn-mortality threshold lying between 185 and 230μgl−1, and growth reductions occurring after 5-week at 108μgl−1 and above, associated with enzymatic perturbations. These results underline a relatively important sensitivity of juvenile cuttlefish to Zn, pointed out by a wide diversity of biomarkers.
Show more [+] Less [-]Inputs of anthropogenic nitrogen influence isotopic composition and trophic structure in SE Australian estuaries Full text
2015
Mazumder, Debashish | Saintilan, Neil | Alderson, Brendan | Hollins, Suzanne
Urban development in coastal settings has increased the input of nitrogen into estuaries globally, in many cases changing the composition of estuarine ecosystems. By focussing on three adjacent estuaries with a gradient of anthropogenic N loadings, we used stable isotopes of N and C to test for changes due to increased anthropogenic N input on the structure of some key trophic linkages in estuaries. We found a consistent enrichment in δ15N corresponding to increased anthropogenic N at the three ecosystem levels studied: fine benthic organic matter, grazing invertebrate, and planktivorous fish. The degree of enrichment in δ15N between fine benthic organic matter and the grapsid crab Parasesarma erythrodactyla was identical across the three sites. The glassfish Ambassis jacksoniensis showed lower levels of enrichment compared to basal food sources at the higher N-loaded sites, suggesting a possible effect of anthropogenic N in decreasing food-chain length in these estuaries.
Show more [+] Less [-]Endangered New Caledonian endemic mushroom coral Cantharellus noumeae in turbid, metal-rich, natural and artificial environments Full text
2015
Gilbert, Antoine | Heintz, Tom | Hoeksema, Bert W. | Benzoni, Francesca | Fernandez, Jean-Michel | Fauvelot, Cécile | Andréfouët, Serge
Since its description in 1984, little attention has been paid to the New Caledonian endemic mushroom coral Cantharellus noumeae (Fungiidae), an IUCN Red-listed, endangered coral species. Our study presents the first ever quantitative assessment conducted on C. noumeae populations for two contrasting sites in the same turbid bay. Sites differed by their substrates of artificial or natural origins. Metal concentrations of superficial sediment were measured. C. noumeae was found in high densities in metal-rich and turbid environments at both locations, reaching up to 288 individuals per 50m2. It was 3.5 times more abundant on natural rock than on artificial substrates. Recruitment was also higher proportionally on rock (47% vs 7–14%). The composition of the associated coral communities included 30–37 species occurring in low densities. Our findings clarify the environmental niche of this species and its colonization potential, in order to eventually better characterize its conservation status.
Show more [+] Less [-]Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics Full text
2015
Napper, Imogen E. | Bakir, Adil | Rowland, Steven J. | Thompson, Richard C.
Cosmetic products, such as facial scrubs, have been identified as potentially important primary sources of microplastics to the marine environment. This study characterises, quantifies and then investigates the sorptive properties of plastic microbeads that are used as exfoliants in cosmetics. Polyethylene microbeads were extracted from several products, and shown to have a wide size range (mean diameters between 164 and 327μm). We estimated that between 4594 and 94,500 microbeads could be released in a single use. To examine the potential for microbeads to accumulate and transport chemicals they were exposed to a binary mixture of 3H-phenanthrene and 14C-DDT in seawater. The potential for transport of sorbed chemicals by microbeads was broadly similar to that of polythene (PE) particles used in previous sorption studies. In conclusion, cosmetic exfoliants are a potentially important, yet preventable source of microplastic contamination in the marine environment.
Show more [+] Less [-]Passive samplers of hydrophobic organic chemicals reach equilibrium faster in the laboratory than in the field Full text
2015
Booij, Kees | Tucca, Felipe
The use of passive sampling methods for monitoring hydrophobic organic chemicals frequently requires the determination of equilibration times and partition coefficients in the laboratory. These experiments are often carried out by exposing passive samplers in a finite water volume, and errors are easily made when the obtained results are applied to the field, where water volumes are essentially infinite. The effect of water volume on the equilibration rate constant is discussed, using a mechanistic model. Application of this model to two literature reports illustrates that aqueous concentrations in the field may be underestimated by a factor of 10 or more, when the water volume effect is neglected. Finally, it is shown that the concept of “sorption capacity” (sampler mass times partition coefficient) allows for a more intuitive understanding of the passive sampling process in small and large water volumes, which may reduce the risk of laboratory-field extrapolation errors.
Show more [+] Less [-]Metal release from contaminated coastal sediments under changing pH conditions: Implications for metal mobilization in acidified oceans Full text
2015
Wang, Zaosheng | Wang, Yushao | Zhao, Peihong | Chen, Liuqin | Yan, Changzhou | Yan, Yijun | Chi, Qiaoqiao
To investigate the impacts and processes of CO2-induced acidification on metal mobilization, laboratory-scale experiments were performed, simulating the scenarios where carbon dioxide was injected into sediment–seawater layers inside non-pressurized chambers. Coastal sediments were sampled from two sites with different contamination levels and subjected to pre-determined pH conditions. Sediment samples and overlying water were collected for metal analysis after 10-days. The results indicated that CO2-induced ocean acidification would provoke increased metal mobilization causing adverse side-effects on water quality. The mobility of metals from sediment to the overlying seawater was correlated with the reduction in pH. Results of sequential extractions of sediments illustrated that exchangeable metal forms were the dominant source of mobile metals. Collectively, our data revealed that high metal concentrations in overlying seawater released from contaminated sediments under acidic conditions may strengthen the existing contamination gradients in Maluan Bay and represent a potential risk to ecosystem health in coastal environments.
Show more [+] Less [-]Heavy metal levels in dune sands from Matanzas urban resorts and Varadero beach (Cuba): Assessment of contamination and ecological risks Full text
2015
Díaz Rizo, Oscar | Buzón González, Fran | Arado López, Juana O. | Denis Alpízar, Otoniel
Concentrations of chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn) and lead (Pb) in dune sands from six urban and suburban Matanzas (Cuba) resorts and Varadero beach were estimated by X-ray fluorescence analysis. Ranges of metal contents in dune sands show a strong variation across the studied locations (in mg/kg−1): 20–2964 for Cr, 17–183 for Ni, 17–51 for Cu, 18–88 for Zn and 5–29 for Pb. The values of contamination factors and contamination degrees how that two of the studied Matanzas's resorts (Judio and Chirry) are strongly polluted. The comparison with Sediment Quality Guidelines shows that dune sands from Judio resort represent a serious risk for humans, due to polluted Cr and Ni levels, while sands from the rest of the studied resorts, including Varadero beach, do not represent any risk for public use.
Show more [+] Less [-]The Marine Strategy Framework Directive and the ecosystem-based approach – pitfalls and solutions Full text
2015
Berg, Torsten | Fürhaupter, Karin | Teixeira, Heliana | Uusitalo, Laura | Zampoukas, Nikolaos
The European Marine Strategy Framework Directive aims at good environmental status (GES) in marine waters, following an ecosystem-based approach, focused on 11 descriptors related to ecosystem features, human drivers and pressures. Furthermore, 29 subordinate criteria and 56 attributes are detailed in an EU Commission Decision. The analysis of the Decision and the associated operational indicators revealed ambiguity in the use of terms, such as indicator, impact and habitat and considerable overlap of indicators assigned to various descriptors and criteria. We suggest re-arrangement and elimination of redundant criteria and attributes avoiding double counting in the subsequent indicator synthesis, a clear distinction between pressure and state descriptors and addition of criteria on ecosystem services and functioning. Moreover, we suggest the precautionary principle should be followed for the management of pressures and an evidence-based approach for monitoring state as well as reaching and maintaining GES.
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