Inmaculada Riba

Comparative toxicity of cadmium in the commercial fish species Sparus aurata and Solea senegalensis

The induction of metallothionein-like proteins (MTLPs) as well as cadmium levels (Cd) was studied in tissues of gilthead sea bream Sparus aurata and flatfish Solea senegalensis after an intraperitoneal (i.p.) injection of cadmium (2.5 mg kg(-1) body weight). The liver, gills, intestine and blood of S. aurata as well as the liver and intestine of S. senegalensis were collected for analysis at 0, 3 and 6 days after the injection. Cd levels significantly increased in all tissues of the treated animals, and the highest accumulation was found in the liver in both species (p<0.05). Cadmium administration provoked significant inductions of MTLP synthesis in the liver and intestine of S. aurata (p<0.05), while no increase in these protein levels was recorded in tissues of S. senegalensis. Our findings imply that MTLP synthesis in S. aurata probably led to an enhanced ability to cope with the toxicant, whereas the MTLP induction in S. senegalensis was inhibited by the accumulated cadmium, as reflected by the mortality rate of this species. Under the experimental conditions, hepatic MTLPs appear to be a good indicator of the Cd level in S. aurata; however, no link was found between the cadmium concentration and MTLP induction in S. senegalensis, which suggests that MTLPs did not play a main role in detoxification by metal sequestration.

Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model

Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration.

Using a classical weight-of-evidence approach for 4-years' monitoring of the impact of an accidental oil spill on sediment quality

In the present report, the successful application of a Weight of evidence approach (WOE) to sediment quality assessment during a four year impact period following an oil spill is discussed. The study assesses the sediment quality on the Galician Coast (NW Spain) which was impacted by an accidental spill associated with the sinking of the tanker Prestige (2002). The assessment is based on three lines of evidence: physicochemical characterization of the sediments; determination of acute toxicity by conducting sediment toxicity tests and benthic alteration including taxonomic identifications along with community descriptive statistics. The data obtained were integrated using a WOE approach by means of two different methodologies: multivariate analysis and ANOVA-based pie charts. Results confirm that PAHs related to the Prestige oil spill are the main contaminant associated with biological effects in the area which has since recovered from the initial acute impact. Also, the WOE allowed the identification of metal contamination not previously described in the area responsible for toxicity in sediments analyzed. In addition, the methodology proposed to link the 3 lines of evidence results shows the use for the first time of an objective indice based on factor analysis which allows pollution of the sediments studied to be qualitatively and quantitatively evaluated while demonstrating the WOE approach to be recommendable in monitoring environmental quality.

An integrated approach to determine sediment quality in areas above CO2 injection and storage in agreement with the requirements of the international conventions on the protection of the marine environment.

The urgent need to reduce the greenhouse emissions to the atmosphere has leaded to study new systems to capture and store carbon dioxide (CO2). The sequestration of CO2 in marine geological formations is one of these systems proposed at the international level to effectively reduce the concentration of atmospheric CO2. Although permanent containment is expected, it is necessary to determine the risk of leakage to the marine environment. The integrated model for the evaluation of the environmental quality of the marine environment will contribute to determine the potential environmental pathways and effects that are relevant to the consideration of the potential consequences of the leakage of CO2 and incidental associated substances from the geological formations to the marine environment. In addition, this model will satisfy the requirements for a safe CO2 storage in sub-seabed geological formations set in the international conventions on the protection of the marine environment (1992 OSPAR Convention and 1996 London Protocol). The objective of this paper is to show how to adapt classical methodologies based on a weight-of-evidence approach to establish the impact of CO2 leaks in the sediment quality. It is described how the classical methods should modify their application when acidification occurs related to CO2 leaks being the main potential impact in these areas.

A multibiomarker approach using the polychaete Arenicola marina to assess oil-contaminated sediments.

Background, aim and scopeMarine and coastal sediments can accumulate substantial concentrations of metals and hydrocarbons, yet the consequences of this contamination for exposed biota in situ can be difficult to establish. Here, we examine the hypothesis that exposure to contaminated sediments can lead to detrimental effects in sediment-dwelling species. The combination of chemical and biological assessment allows the identification of the impact of chemical contamination, and their use as assessment tools is becoming increasingly important.Materials and methodsThe study was applied to marine sediments from the Bay of Algeciras (S Spain) impacted by multiple, low-level contaminant inputs, and the Galician Coast (NW Spain), historically impacted by an oil spill (Prestige 2002), with two reference sites selected in UK and Spain. The common lugworm Arenicola marina was exposed in the laboratory for 14xa0days to the marine sediments, and a suite of biomarkers of sublethal toxicity was combined with analytical chemistry to test for relationships between sediment contamination and effect.ResultsModerate to strong correlations between organics, metals, and biological responses were observed, with DNA damage as measured using the Comet assay forming the largest contribution toward the observed differences (pu2009<u20090.05). The responses of worms from sites experiencing different contamination loads were clearly distinguishable.DiscussionWe show how a combination of multibiomarkers with analytical chemistry can be used to investigate the toxicity of marine sediments, enabling the differentiation of sites showing different types of contamination. There are clear relationships in sublethal assays that can be related to the putative mode of toxicity of the contaminants.ConclusionsThe use of A. marina in this way provides a sensitive, holistic approach to sediment toxicity assessment, enabling comparisons between oil-polluted sites to be quantified.Recommendations and perspectivesThese tools provide a relatively simple, rapid, and economic way to test the environmental status of oil-contaminated sediment.

Linking Sediment Chemical and Biological Guidelines for Characterization of Dredged Material

Abstract Dredged material management in Spain and possible options for the different categories is discussed according to chemical sediment quality guidelines. Also an approach using an integrated assessment that includes biological end points as part of a tiered testing schema is discussed for future implementation in Spanish recommendations. To establish the feasibility of using both kinds of guidelines, an example of the utility and validity of the approach that links both chemical and biological guidelines proposed for the management of dredged material characterization processes data from a particular case study associated with a port in the north of Spain are discussed. The use of both kinds of methodologies, together with the necessity of assessing the bioavailability of some contaminants, has been shown as a powerful tool for the best selection of different disposal options of dredged material in the case study described.

Software, Data and Modelling News: SQA: a software tool for integrated sediment quality evaluation based on the Weight-Of-Evidence procedure

A new software tool for integrative sediment quality assessment is developed. The program is based on WOE methodologies which together may be used for assessing degree of contamination in marine sediment. Statistical analysis of field-collected and lab-based data is performed by means of commercial statistical software package Statistica 6.0. The designed tool provides user-friendly interface, is extremely easy in use, greatly simplifies statistical analysis process, interprets the results in text and graphical format.