An evidence of salinity impact on the bioaccumulation of heavy metals in fishes collected from the Messolonghi lagoon in Greece

The impact of salinity and water exchange rate on the accumulation of heavy metals in the benthic fish Zosterissesor ophiocephalus, collected from the shallow sublagoons Tholi and Paleopotamos, was studied. Both sublagoons are influenced by the intensive agricultural activity of the surrounding area in terms of the chemical substances’ drainage, and by the untreated sewage discharges of an urbanized area with Paleopotamos being affected in lesser extent. Paleopotamos is characterised by restricted water renovation, resulting to much higher salinity than Tholi. The bioaccumulation of the heavy metals studied (Manganese, Zinc and Copper), reveals differences among the metals with females showing higher values. Specimens from Paleopotamos showed statistically significant higher bioaccumulation of the heavy metals in both sexes, which is attributed to the extremely high salinity of this sublagoon.     

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium (Cd) pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination: the industrialized coast of Sfax (S1), the coast of Douar Chatt (S2) and the coast of Luza (S3). The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher (p < 0.0001) than those from S2 and S3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order: S1 > S2 > S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors (BAF) greater than 1 in all studied sites. In S1 and S2, BAF values respect the following order: S. basilisca > Z. ophiocephalus > S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccumulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gabes.     

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca,Zosterisessor ophiocephalus and Solea vulgaris collected from the Guff of Gabes in Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium (Cd) pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination: the industrialized coast of Sfax (S1), the coast of Douar Chart (S2) and the coast of Luza ($3). The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher (p<0.0001) than those from S2 and $3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order: S1>S2>S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors (BAF) greater than 1 in all studied sites. In S1 and S2, BAF values respect the following order: S. basilisca>Z. ophiocephalus>S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccamulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gahes.