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An approach is presented for determining the influence of two key variables, pH and salinity (S), on the toxicity of four common heavy metals bound to sediments in estuaries. Two samples of environmental sediment taken from two estuaries in southern Spain (the Huelva estuary and the Guadalquivir River estuary), together with a dilution of toxic mud from the(More)
On five marine microalgae with the same biovolume quantity (Tetraselmis chuii, Rhodomonas salina, Chaetoceros sp., Isochrysis galbana (T-iso) and Nannochloropsis gaditana) 72-h exposure toxicity tests with copper and lead were performed. For both metals, 72-h EC50s showed T. chuii as the most tolerant and R. salina as one of the most sensitive. Besides(More)
Five marine microalgae (Tetraselmis chuii, Rhodomonas salina, Chaetoceros sp., Isochrysis galbana (T-iso) and Nannochloropsis gaditana), in the same biovolume quantity, were exposed to 72h growth-inhibition tests with atrazine and LAS. In all cases, the inhibition effect of atrazine was higher than that of LAS up to two orders of magnitude higher in the(More)
To evaluate sediment quality in different areas in the Gulf of Cádiz affected by mining activities, an integrative approach to assessment was used: the Sediment Quality Triad (SQT). Sediment samples were collected at six stations and subjected to replicated sediment acute and chronic toxicity tests, and comprehensive sediment chemistry analyses. Organisms(More)
Population decline of the rotifer Brachionus plicatilis has been evaluated as a sensitive and reliable bioassay for assessing toxicity of marine sediment interstitial water. Three environmental conditions were examined using both interstitial and seawater cultures: (a) adverse effects from dissolved contaminant concentrations; (b) effects from particulate(More)
To seasonally evaluate littoral contamination, toxicity and quality values of sediments from the Gulf of Cádiz, we measured chemical concentrations and conducted toxicity tests in winter and summer and linked these results by means of multivariate analysis. Sediment samples were subjected to two separate, replicated sediment toxicity tests (Microdeutopus(More)
The Natural Park of Doñana and the Guadalquivir estuary were impacted by the release of 6 million cubic meters of acid waste after the mine-tailing spill in Aznalcóllar (Andalusia, SW, Spain). Here is presented the monitoring of the accidental spill on vertical distribution of heavy metals in the estuarine sediments. The total concentration of six metals(More)
This paper summarises the performance of simple multivariate exploratory analyses to investigate on their potential application for dredged material characterization and management. The data from 25 sampling stations located at 7 different Spanish ports, produced a matrix consisting of 300 observations on 10 variables: the metals Cd, Cu, Cr, Hg, Ni, Pb and(More)
Standard microalgae toxicity tests should be able to establish responses in real ecosystems. Natural marine picoplankton samples collected during the months of March, June, August, October 2007 and January 2008, where exposed to 72 h copper toxicity tests. Results analysed by flow cytometry distinguished two groups, with different cytometric characteristics(More)
Most studies of oxygen solubility values for high salinity conditions have used synthetic solutions. The object of this study is therefore to propose an equation, valid for high salinity conditions, based on the analysis of oxygen saturation in evaporated seawater. In this study, the solubility of oxygen in evaporated seawater has been determined over a(More)