Search results for "Underwater"
showing 10 items of 1058 documents
Contaminants of emerging concern in freshwater fish from four Spanish Rivers.
2019
This study investigated the occurrence of 135 contaminants of emerging concern (CECs) – pharmaceuticals, pesticides, a set of endocrine disrupting compounds (EDCs) (parabens, bisphenols, hormones, triazoles, organophosphorus flame retardants and triclosan), UV-filters, perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) – in 59 fish samples, collected in 2010 in 4 Spanish Rivers (Guadalquivir, Júcar, Ebro and Llobregat). Of the 135 CECs, 76 including 8 pharmaceuticals, 25 pesticides, 10 EDCs, 5 UV-filters, 15 PFASs and 13 HFRs were detected. Pharmaceuticals were the less frequently found and at lower concentrations. Pesticides, EDCs, UV-filters, PFASs and HFRs were det…
Biostimulation of in situ microbial degradation processes in organically-enriched sediments mitigates the impact of aquaculture
2019
Fish farm deposition, resulting in organic matter accumulation on bottom sediments, has been identified as among the main phenomena causing negative environmental impacts in aquaculture. An in situ bioremediation treatment was carried out in order to reduce the organic matter accumulation in the fish farm sediments by promoting the natural microbial biodegradation processes. To assess the effect of the treatment, the concentration of organic matter in the sediment and its microbial degradation, as well as the response of the benthic prokaryotic community, were investigated. The results showed a significant effect of the treatment in stimulating microbial degradation rates, and the consequen…
How building an underwater pipeline connecting Libya to Sicilian coast is affecting environment: polycyclic aromatic hydrocarbons (PAHs) in sediments…
2009
The purpose of this study was to determine the variation of concentrations and distribution of PAHs in the sediments of the Gela coastal area (Italy) caused by the construction of an underwater pipeline connecting Libya to Sicilian coast. The receiving terminal of offshore pipeline, crossing the Mediterranean Sea, 516 Km long, up to 1127 meters deep, is located in Gela (Sicily, Italy). No bibliographic data regarding hydrocarbons are available for this area. In this paper we report the results of analysis on the water and organic along PAHs.The total concentrations of 16 PAHs in the sediments, analyzed during five surveys, ranged from 2.4 to 434 microg/kg of dry weight. The highest concentr…
Accumulation of trace metals in sediments in a Mediterranean Lagoon: Usefulness of metal sediment fractionation and elutriate toxicity assessment.
2015
International audience; The authors investigated sediment quality in Bizerte Lagoon (Tunisia) focusing on geochemical characteristics, metal sediment fractionation and elutriate toxicity assessment. Nickel, Cu, Zn, Pb, Cr and Cd partitioning in sediments was studied; accumulation and bioavailability were elucidated using enrichment factors, sequential extractions, redox potential, acid volatile sulfide and biotest procedures in toxicity evaluation. Results revealed an accumulation for Pb and Zn, reaching 99 and 460 mg kg−1 respectively. In addition, the acid volatile sulfide values were high in both eastern and western lagoon areas, thus affecting metal availability. Mean enrichment factor …
Toxicity Testing of Silver Nanoparticles in Artificial and Natural Sediments Using the Benthic Organism Lumbriculus variegatus
2016
The increased use of silver nanoparticles (AgNP) in industrial and consumer products worldwide has resulted in their release to aquatic environments. Previous studies have mainly focused on the effects of AgNP on pelagic species, whereas few studies have assessed the risks to benthic invertebrates despite the fact that the sediments act as a large potential sink for NPs. In this study, the toxicity of sediment-associated AgNP was evaluated using the standard sediment toxicity test for chemicals provided by the Organization of Economic Cooperation and Development. The freshwater benthic oligochaete worm Lumbriculus variegatus was exposed to sediment-associated AgNP in artificial and natural …
An orbital floating time scale of the Hauterivian/Barremian GSSP from a magnetic susceptibility signal (Río Argos, Spain).
2012
10 pages; International audience; An orbital floating time scale of the HauterivianeBarremian transition (Early Cretaceous) is proposed using high-resolution magnetic susceptibility measurements. Orbital tuning was performed on the Río Argos section (southeast Spain), the candidate for a Global boundary Stratotype Section and Point (GSSP) for the HauterivianeBarremian transition. Spectral analyses of MS variations, coupled with the frequency ratio method, allow the recognition of precession, obliquity and eccentricity frequency bands. Orbitallytuned magnetic susceptibility provides minimum durations for ammonite biozones. The durations of well-constrained ammonite zones are assessed at 0.78…
Primary productivity variability on the Atlantic Iberian Margin over the last 70,000 years: Evidence from coccolithophores and fossil organic compoun…
2010
[1] This study analyzes coccolithophore abundance fluctuations (e.g., Emiliania huxleyi, Gephyrocapsa specimens, and Florisphaera profunda) in core MD01-2444 sediment strata retrieved at the Iberian Margin, northeastern Atlantic Ocean. Coccolithophores are calcareous nannofossils, a major component of the oceanic phytoplankton, which provide information about past ecological and climatological variability. Results are supported by data on fossil organic compounds (sea surface temperatures, alkenones, and n-hexacosan-1-ol index) and geochemical analyses (benthic δ13Ccc and planktonic δ18Occ isotopes). Three scenarios are taken into account for this location at centennial-scale resolution ove…
Nutritional Characterization of Sea Bass Processing By-Products
2020
The consumption of functional foods and nutraceuticals is gaining more importance in modern society. The exploration of alternative sources and the utilization of by-products coming from the food industry are gaining more importance. The present study aimed to characterize the nutritional value and potential use of sea bass by-products as a source of high-added-value compounds for the development of supplements. The chemical composition (moisture, protein, fat, and ash contents) and profiles of amino acids (high-performance liquid chromatography coupled to a scanning fluorescence detector), fatty acids (gas chromatography coupled to a flame ionization detector), and minerals (inductively co…
Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea
2016
11 pages, 4 figures
Concurrent environmental stressors and jellyfish stings impair caged European sea bass (Dicentrarchus labrax) physiological performances
2016
9 pages, 5 figures, 4 tables