Cellular biomarkers for monitoring estuarine environments: Transplanted versus native mussels

In developed countries, estuarine environments are often subjected to chemical pollution, whose biological impact is profitably evaluated by the use of multi-biomarker approaches on sentinel species. In this paper, we investigate genotoxicity and lysosomal alterations in the Mediterranean mussel (Mytilus galloprovincialis), from the estuary of the River Cecina (Tuscany, Italy), selected as "pilot basin" within the Water Frame Directive (2000/60 European Community). Both native and 1 month transplanted mussels were used in order to compare these two approaches in terms of sensitiveness of specific biomarker responses. Genotoxic effects were evaluated as strand breaks, by single cell gel electrophoresis (or Comet assay), and as chromosomal alterations, by the micronucleus test in gill cells. Lysosomal alterations were assessed by the neutral red retention time (in haemocytes), lipofuscin accumulation and ultrastructure (in digestive cells). Heavy metal bioaccumulation was also analysed. Mussels from the River Cecina showed a general alteration of all the biomarkers investigated, accompanied by an elevation of tissue metal levels. However, some differences in specific responses occurred between transplanted and native mussels. Early biomarkers, such as those based on DNA and lysosomal membrane integrity, were induced at similar degree in native and transplanted mussels; while alterations resulting from cumulative events, as the increase of micronuclei frequency were much more elevated in native specimens (23.1+/-7.6) than in transplanted (9.3+/-4.7) and reference ones (5.8+/-5.2). Similarly, the comparison between lipofuscin accumulation and mean lysosomal diameter in impacted and control sites, gave significant differences exclusively with transplanted mussels. These results suggest that the parallel use of caged and native mussels in environmental biomonitoring can improve the characterization of the study area

DNA damage in eelpout (Zoarces viviparus) from Goteborg harbour

The relationship between DNA damage and the exposure of marine organisms to environmental contaminants was examined in the Goteborg harbour area. This research is part of a wider ecotoxicological study planned to evaluate the biological impact of chemical contamination in the River Gota estuary, following a bunker oil (10-100 tonnes) spill occurred in June 2003. Here we present data on the DNA strand breaks derived using the comet assay and the presence of apoptotic cells using the diffusion assay in nucleated erythrocytes of the eelpout (Zoarces viviparus) from the study area and at a clean reference site. Polycyclic aromatic hydrocarbon metabolites were also analyzed in the bile of exposed fish. The results showed a high level of damaged DNA, paralleled by a peak in bile PAH metabolites, in fish from the most impacted site, 3 weeks after the oil spill. A significant recovery was observed in specimens from the spill site, 5 months later, but not in fish caught in the middle part of Goteborg harbour, which is chronically subjected to heavy chemical pollution. The levels of apoptic cells did not show any marked variations, but a significant recovery was observed in fish from the oil impacted site 5 months after the spill

Cellular biomarkers for monitoring estuarine environments: transplanted versus native mussels.

Abstract In developed countries, estuarine environments are often subjected to chemical pollution, whose biological impact is profitably evaluated by the use of multi-biomarker approaches on sentinel species. In this paper, we investigate genotoxicity and lysosomal alterations in the Mediterranean mussel (Mytilus galloprovincialis), from the estuary of the River Cecina (Tuscany, Italy), selected as “pilot basin” within theWater Frame Directive (2000/60 European Community). Both native and 1 month transplanted mussels were used in order to compare these two approaches in terms of sensitiveness of specific biomarker responses. Genotoxic effects were evaluated as strand breaks, by single cell gel electrophoresis (or Comet assay), and as chromosomal alterations, by the micronucleus test in gill cells. Lysosomal alterations were assessed by the neutral red retention time (in haemocytes), lipofuscin accumulation and ultrastructure (in digestive cells). Heavy metal bioaccumulation was also analysed. Mussels from the River Cecina showed a general alteration of all the biomarkers investigated, accompanied by an elevation of tissue metal levels. However, some differences in specific responses occurred between transplanted and native mussels. Early biomarkers, such as those based on DNA and lysosomal membrane integrity, were induced at similar degree in native and transplanted mussels; while alterations resulting from cumulative events, as the increase of micronuclei frequency were much more elevated in native specimens (23.1±7.6) than in transplanted (9.3±4.7) and reference ones (5.8±5.2). Similarly, the comparison between lipofuscin accumulation and mean lysosomal diameter in impacted and control sites, gave significant differences exclusively with transplanted mussels. These results suggest that the parallel use of caged and native mussels in environmental biomonitoring can improve the characterization of the study area

Effects of algal extracts (Polysiphonia fucoides) on rainbow trout (Oncorhynchus mykiss): A biomarker approach

The genotoxicity of algal extracts (Polysiphonia fucoides) was investigated in erythrocytes of rainbow trout (Oncorhynchus mykiss). Trout were exposed to 0.5% of the algal extract for 7 days. Comet assay (alkaline and neutral versions) and Micronucleus test were used to assess DNA damage, and Diffusion Assay to detect apoptotic cells. EROD activities and oxidative stress parameters in rainbow trout liver were also measured. A significant induction of DNA single strand breaks comparable to the ones induced by the in vivo exposure to 20 mg/kg B[a]P was observed at the end of the treatment, while increases of double strand breaks and apoptotic cells were not observed. The absence of activation of antioxidant responses seems to underline a mechanism of action of the genotoxic algal extract which does not involve oxidative stress