Toxicity of lindane (gamma-hexachloroxiclohexane) in Sparus aurata, Crassostrea angulata and Scrobicularia plana.

The purpose of the present study was to research the sublethal and/or lethal effects produced by the exposure of fish and shellfish to the gamma isomer of lindane, gamma-hexachlorocyclohexane (gamma-HCH). The teleostean fish Sparus aurata and the shellfish Crassostrea angulata and Scrobicularia plana, were exposed to 16 micro g/L of lindane for 15 days. Samples of different fish (liver, kidney and gills) and shellfish (gills, gut, digestive gland and mantle) tissues were extracted and processed for histopathological observations. Although mortality was not detected during the bioassay, sublethal effects (histopathological alterations) were observed. Vacuolization in the liver cells and lamellar fusion in gills from exposed fish were observed. Disorganization of normal gill structure, epithelial desquamation with the disappearance of apical ciliature in intestine, and inflammatory response in mantle from exposed shellfish were also observed. Thus, it can be concluded that the lindane concentration employed in the present research did not produce lethal effects in the exposed organisms but it caused sublethal effects. Lindane has time-dependent multiple toxic effects in S. aurata, C. angulata and S. plana, which were more severe at the end of the experimental time. The toxicological implications arising from these results are subjects for further multiconcentration tests dealing with lethal responses (mortality) or with sublethal responses (cellular/molecular biomarkers) of the aforementioned species.

Chronic bioassay in benthic fish for the assessment of the quality of sediments in different areas of the coast of Spain impacted by acute and chronic oil spills.

More and more, the coastal regions of the world suffer from the contamination of petroleum hydrocarbon [principally polycyclic aromatic hydrocarbons (PAHs)]. This contamination can be acute, as it happened in the Coast of Galicia (NW, Spain) by the oil spill from a tanker, or chronic by the existence of high maritime traffic and a lot of industries as it is the case of the Bay of Algeciras (BA) (SW, Spain). It is of a great concern due to the toxicity, especially in sediments and ecosystem associated to it. The objective of this study is to assess, through chronic bioassay, sediment toxicity in samples collected in different littoral areas of Spain and to compare the damage caused in benthic fish, Solea senegalensis, according to that which suffers acute spill (Coast of Galicia) or chronic spill (the BA) by means of histopathology methods and enzymatic activities studies. Organisms were exposed to different sediments from Galician Coast and the BA during 42 days and every sample was analyzed by triplicate in glass aquaria. At the end of the bioassay, histopathological diseases were analyzed in the gills, target organ. Likewise, stress parameters as ethoxyresorufin-O-deethylase (EROD) and the glutathione S-transferases (GSTs) activities were determined in the liver. Results showed a significant positive correlation between the biomarkers of exposure (EROD and GST), biomarkers of effect (histopathology), and PAHs concentrations in the sediments.

Lindane toxicity on early life stages of gilthead seabream (Sparus aurata) with a note on its histopathological manifestations.

Eggs/embryos and larvae were exposed to nominal concentrations ranging from 0.1 to 10mg/L lindane. High percentage of mortality was observed in larvae exposed to 1mg/L (76.38%) and in embryos exposed to 10mg/L (81.98%) of lindane at 24h exposure. The acute toxicity expressed as LC(50) 48-h was 0.122mg/L for embryos and 0.318mg/L for larvae. Larvae alterations included weak swimming, incapacity to respond to external stimuli, uncoordinated movements, trembling, myoskeletal defects, opaque skin and exophthalmia. Mucous epithelium of the digestive tissue showed a severe alteration with hypertrophy and desquamation of mucous cells. A high cellular disorganization in the renal and hepatic tissue is observed. Results obtained showed the sensitivity of Sparus aurata early life stages to lindane and the presence of sublethal effects like histopathological alterations; therefore, the relevance of pesticides substances control in the aquatic environment.