Advances on the Applications of Fish Biomarkers in the Aquatic Toxicity of Heavy Metals

Heavy metal pollution has attracted worldwide concerns as it threatens both the aquatic organisms and the integrity of aquatic ecosystem. Moreover, human health has faced up the challenges due to its bioaccumulation through the food chains, among of which fish consuming has been one of the important ways. This paper reviewed the sources of trace metals in coastal waters and analysed the toxicity of trace metals and its toxic mechanisms to fish as well. Recent researches and applications of the biomarkers which can quantify the response fish to pollution stress mainly including the cytochrome P450 enzymes, heat shock protein, metallothionein, antioxidant enzymes and gentoxicology (DNA damage by comet assay), histopathological and morphological parameters were summarized. Finally, the paper discussed these questions to be solved in future: to improve the applications of fish biomarkers and to combine the chemical analysing method, biochemical assay and biomarkers response testing in assessing the risks of pollutants to aquatic ecosystem still need to be studied further.