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.     

Study on the sensitivity to cadmium of marine fish Salaria basilisca（Pisces： Blennidae）

The present study tested the sensitivity of Salaria basilisca to water-cadmium (Cd) contamination. For this purpose, liver somatic index (LSI), Cd concentrations and the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured in the liver of S. basilisca exposed to Cd-contaminated water (2 mg Cd/L as CdCl2) for 14 and 28 d. The results showed that the LSI decreased significantly after 14 and 28 d of Cd-exposure. Cd bioaccumulation in the liver resulted in an increasing uptake up to 42 g/g dry weight after 28 d of exposure. Activities of CAT and SOD were significantly increased with increasing exposure time. A significant increase in GSH-Px activity, under Cd influence, was observed during 14-day exposure period (p < 0.0001). However, a significant decrease (p < 0.05) in this activity with respect to control fish was registered after 28 d of Cd-exposure. These results showed that Cd accumulation in the liver of S. basilisca could induce oxidative stress as demonstrated by changes in the antioxidant enzyme activities. Results also emphasized that S. basilisca may considered as a sensitive species to Cd exposure.     

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.