Bioaccumulation of metals in tissues of Solea vulgaris from the outer coast and Ria de Vigo, Ne atlantic [Spain]

Ria and coastal zone are, in particular, vulnerable to heavy metals pollution. Concentrations of 10 metals in liver, muscle and kidney of the sole [Solea vulgaris] from Ria of Vigo and its coastal zone [Spain] were measured from April 2006 to February 2007 and the relationships between fish size age and metal concentrations in the tissues was investigated. Concentrations of the heavy metals in examined fish ranged as follows: Cd [0.01 - 0.7], Pb [0.1 - 2.5], Hg [0.01 - 0.7], Cu [3.3- 46.7], Zn [15- 274], As [3-151], Se [0.9- 18.2], Mn [0.9- 9.76] microg/g dryweight. Kidney and liver showed the highest levels of Cd, Cu, Pb and Zn. The concentration of metals was significantly affected by the sampling site and fish tissues. Our results indicated that all heavy metals were found the highest in muscle tissue. A comparison of metals concentration in fishes from both sites showed higher bioaccumulation in the examplars captured in Ria. This indicates that there is a trend of higher metal pollution level in the estuarine environment. Although, metals levels in the tissues in the area do not exceed contamination levels, measures are recommended for lowering heavy metals inputs into Ria of Vigo. Heavy metals in the edible parts of the investigated fish were in the permissible safety levels for human uses

Toxic effects of acute exposure of diazinon in turbot [Psetta maxima] early life stage [ELS]

In the present study, the toxic effects on the embryos and larvae of the turbot were used as a model to investigate the diazinon, which contaminates aquatic ecosystems. The number of dead embryos significantly increased in response to diazinon concentrations 0.2, 0.4, 0.8, 1.6, 3.2, and 7.4 mg/L. The 48h LC[50] value of diazinon for turbot embryos was estimated at 1.85 mg/L. Dose-response decreases in hatching success were recorded as 97, 92.4, 80.3, 60.3, 38.7 and 27.1%, respectively. The number of dead larvae significantly increased with increasing diazinon concentrations exposed for 24-96 h [p < 0.05]. The 24, 48, 72 and 96h LC[50] values of diazinon for turbot larvae were estimated at 4.8 [6.4-5.12], 3.3 [4.73-2.52], 2.1 [3.29-1.65] and 1.23 [0.87-2.38] mg/L, respectively. There were significant differences in the LC[50] values obtained at different exposure times [p <0.05]. Diazinon caused lethal toxicity as well as nonlethal malformations during embryo-larvae development