Luís M. Lubián

The differential sensitivity of five chlorophyll c-containing marine microalgae to different components of solar radiation, e.g. photosynthetic active radiation (PAR), ultraviolet-A (UV-A) and ultraviolet-B (UV-B), was investigated in an exclusion experiment involving exposure to PAR, PAR+UV-A and PAR+UV-A+UV-B (P-, PA- and PAB-treatment, respectively) for 20 min and subsequent recovery for up to 24 h in dim light. The decrease in

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 organic matter; and (c) increase or decrease of bacterial biomass from addition of mixtures

Pigment composition and its variation with culture agewere analyzed in six strains of Nannochloropsis (Eustigmatophyceae). The capacity for accumulationof the ketocarotenoids astaxanthin and canthaxanthinwas higher in N. salina and N. gaditanathan in the other ...

This study consisted of the sediment toxicity assessment of the Bay of Cádiz based on two endpoints: growth
inhibition for Cylindrotheca closterium (benthic microalgae) and fecundity inhibition for Tisbe battagliai
(harpacticoid copepod). A new methodology to eliminate (but not as storage technique) the autochthonous
biota present in the sediment samples by immersing them in liquid nitrogen (−196 °C) was also assessed.
Sediment toxicity data showed different toxicity levels for both organisms. In general, T. battagliai was more
sensitive; however a good correlation (r=0.75; p b0.05) between sediment toxicity results for both species
was found. Data in pore water (pH, redox potential, and toxicity for microalgae and copepod) and sediment
(pH, redox potential, organic carbon, and metal concentrations) demonstrated that ultra-freezing did not
alter sample characteristics; thus, this technique can be adopted as a pre-treatment in whole-sediment
toxicity tests in order to avoid misleading results due to presence of autochthonous biota. Multivariate
statistical analysis such as cluster and principal component analysis using chemical and ecotoxicological data
were employed. Silt and organic matter percentage and lead concentration were found to be the factors that
explain about 77% of sediment toxicity in the Bay of Cádiz. Assay methodology determined in this study for
both assayed species is considered adequate to be used in sediment toxicity monitoring programs. Results
obtained using both species show that the Bay of Cádiz can be considered a moderately polluted zone.