Use of zebra fish eggs as early indicators of aquatic environmental pollution

Abstract

Our study used mortality and developmental abnormalities present in fertilized zebra fish eggs as a possible useful bio-indicator to assess water pollution from the vicinity of five great swine units using 48-hour in vitro zebra fish eggs acute toxicity test. In assay, 1,300 (Test) and 220 (Control) healthy fertilized zebra fish eggs were used. During the test duration, a number of dead eggs or embryos and/or any other disturbance in the embryonic development that could indicate pollution were ascertained. In parallel, embryonic mortality was assessed for each swine unit possible farm effluent source, using double samples and 10 different water dilutions provided from the environs river. It was found in some situations that fertilized fish egg development was disturbed by the water components at the assay moment. Statistical results, analyzed according to the Kolmogorov-Smirnov normality test (significant P<0.05, or lower), revealed that, from the five observed units at the sample collection moment, the river water was polluted in the surroundings of swine Units 1 and 4, which was also confirmed by the acute toxicity endpoints presence in developed embryos in the water samples provided. This qualitative assay could be a helping tool for small-scale environmental risk assessment due to the opportunity to achieve, in a short amount of time, an accurate analysis.