A Test Battery Approach for the Ecotoxicological Evaluation of Estuarine Sediments

Radiation and Environmental Science Centre, FOCAS Institute, Dublin Institute of Technology, Ireland.
Ecotoxicology (Impact Factor: 2.71). 11/2005; 14(7):741-55. DOI: 10.1007/s10646-005-0022-8
Source: PubMed


The purpose of this study was to evaluate the overall sensitivity and applicability of a number of bioassays representing multiple trophic levels, for the preliminary ecotoxicological screening (Tier I) of estuarine sediments. Chemical analyses were conducted on sediments from all sampling sites to assist in interpreting results. As sediment is an inherently complex, heterogeneous geological matrix, the toxicity associated with different exposure routes (solid, porewater and elutriate phases) was also assessed. A stimulatory response was detected following exposure of some sediment phases to both the Microtox and algal bioassays. Of the bioassays and endpoints employed in this study, the algal test was the most responsive to both elutriates and porewaters. Salinity controls, which corresponded to the salinity of the neat porewater samples, were found to have significant effects on the growth of the algae. To our knowledge, this is the first report of the inclusion of a salinity control in algal toxicity tests, the results of which emphasise the importance of incorporating appropriate controls in experimental design. While differential responses were observed, the site characterised as the most polluted on the basis of chemical analysis was consistently ranked the most toxic with all test species and all test phases. In terms of identifying appropriate Tier I screening tests for sediments, this study demonstrated both the Microtox and algal bioassays to be more sensitive than the bacterial enzyme assays and the invertebrate lethality assay employing Artemia salina. The findings of this study highlight that salinity effects and geophysical properties need to be taken into account when interpreting the results of the bioassays.

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    • "Many authors have shown that bioassays provide a general indication of metal bioavailability/toxicity in sediments (Latif and Licek 2004; Harikumar and Nasir 2010; Baran and Tarnawski 2013; Besser et al. 2014). Bioassays are a useful tool whose application enables a fuller classification of ecological risk resulting from the presence of chemical substances in sediments, their bioavailability, and interactions (Mankiewicz-Boczek et al. 2008; Nendza 2002; Davoren et al. 2005; Narracci et al. 2009; Buitrago et al. 2013). Many authors emphasize that bioassays are a good complement to chemical analyses in procedures of sediment quality assessment (Wadhia and Thompson 2007; Mamindy-Pajany et al. 2011). "
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    ABSTRACT: The aim of this study was to assess heavy metals mobility and toxicity in sediments collected from a dam reservoir in the conditions of intensive human impact by using chemical fractionation and a battery of bioassays. In the studies, the test organisms were exposed to substances dissolved in water (Microtox, Phytotestkit) as well to substances absorbed on the surface of solid particles (Phytotoxkit, Ostracodtoxkit F). The studies showed that sediments from the Rybnik reservoir are toxic, but the tested organisms showed different sensitivity to heavy metals occurring in the bottom sediments. The sediment samples were classified as toxic and very toxic. Moreover, the studies showed a higher toxicity in solid phases and whole sediment than in pore water. The lowest sensitivity was observed in H. incongruens (solid phases) and V. fischeri (pore water, whole sediment). The studies revealed that the toxicity of the sediments is caused mainly by heavy metal forms associated with the solid phase of the sediments. The studies did not confirm the metals occurring in fraction I (exchangeable) to be bioavailable and toxic to living organisms because most correlations between the metal concentration in fraction I and the response of the organisms were negative. The highest mobility from the bottom sediments was found in zinc, average mobility-in copper, cadmium and nickel, and low mobility-in chromium and lead. Organic matter is likely to be the most important factor controlling metal distribution and mobility in the studied sediments.
    Ecotoxicology 06/2015; 24(6). DOI:10.1007/s10646-015-1499-4 · 2.71 Impact Factor
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    • "In order to estimate the real risk of contaminants, chemical analyses have to be complemented with biological and toxicological assays (Ghirardini et al. 1999; Fent 2003; Tsui and Chu 2003). Although chemical analysis is able to record both source substances and their metabolites, it cannot provide information about the effect upon biota (Champan et al. 1992; Davoren et al. 2005; García-Lorenzo et al. 2009). In addition, chemical contaminants rarely affect organisms as single substances but instead cause adverse effects as diverse mixtures (O' Halloran 2006; Manzo et al. 2008a). "
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    ABSTRACT: Ports and harbors may represent a threat for coastal ecosystems due to pollutant inputs, especially those derived from maritime activities. In this study, we report a first assessment of the ecotoxicological threat posed by six ports and harbors of opposite coastal regions, Apulia and Albania, in the southern Adriatic Sea (Italy). A bioassay battery consisting of four different species representing different trophic levels, algae Dunaliella tertiolecta, bacteria Vibrio fischeri, crustacean Artemia salina, and echinoids Paracentrotus lividus, has been used to assess sediment elutriates, pore waters, and sediment suspensions. Two different approaches of toxicity data integration, worst case and integrated index, have been used to determine the most appropriate procedure for the investigated sites. All sites with the worst case approach showed high toxicity levels. The chronic test with algae was the most sensitive identifying the highest effects in the battery. This effect can be attributable to contaminants derived from antifouling paints. The sediments, evaluated with V. fischeri test, often showed toxicity not found in the aqueous matrices of the same sites and that can be mainly linked to organic compounds. The test battery used in this study allowed us to perform a preliminary screening of the ecotoxicological risk of the studied area. In fact, the species utilized for toxicity tests responded differently to the investigated samples, showing different sensitivity. The test battery integrated index did not allow highlighting the differences among the sites and showed a general high ecotoxicological risk. A larger number of tests with higher sensitivity together with a tailored attribution of weights to endpoints and matrices will improve the final site evaluation.
    Environmental Monitoring and Assessment 07/2014; 186(11). DOI:10.1007/s10661-014-3915-2 · 1.68 Impact Factor
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    • "Consequently, several sediment samples from the sediment traps and the treatment wetland were assessed. There is a wide range of toxicity methods available for this type of investigation (Keddy et al., 1995; Davoren et al., 2005). In this study test methods and test organisms were selected that cover a range of endpoints and are internationally used and accepted. "
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    ABSTRACT: Four bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed a low toxicity in porewater and only one sample was weakly toxic in the whole sediment test when assessed with Aliivibrio fischeri (Vibro fischeri). No genotoxicity was detected in the umu test. The toxicity response in the H4IIE- luc test evaluating the presence of dioxin-like compounds was considerably higher in the samples from the sediment traps. The hazard of the sediment therefore appears to be highest in the sediment traps and pond 1 with the methods employed. The result indicates that the wetland system has a design supporting the concentration and sequestration of toxic substances in the first part of the wetland. Based upon the results we suggest that hazard assessment of sediments from other treatment wetlands for landfill leachate should be conducted.
    Ecotoxicology and Environmental Safety 09/2013; 97. DOI:10.1016/j.ecoenv.2013.08.010 · 2.76 Impact Factor
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