Assessing contamination levels of Laguna Lake sediments (Philippines) using a contact assay with zebrafish ( Danio rerio) embryos

• Published in: The Science of the total environment 2005-07, Vol.347 (1), p.254-271
• Main Authors: Hallare, A.V., Kosmehl, T., Schulze, T., Hollert, H., Köhler, H.-R., Triebskorn, R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Bioavailability; Biological and medical sciences; Carbon - analysis; Danio rerio; Ecotoxicology, biological effects of pollution; Embryo, Nonmammalian - abnormalities; Embryo, Nonmammalian - metabolism; Embryotoxicity; Environmental Monitoring; Fresh Water; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Geologic Sediments; Heat shock proteins; Heavy metals; HSP70 Heat-Shock Proteins - metabolism; Laguna Lake; Metals, Heavy - analysis; PAHs; Perylene; Philippines; Polycyclic Aromatic Hydrocarbons - analysis; Sediment toxicity; Survival Rate; Synecology; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Zebrafish; Zebrafish - abnormalities; Zebrafish - embryology; Zebrafish - metabolism
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2004.12.002

The present study investigated the suitability of a sediment contact assay using zebrafish ( Danio rerio) embryos to evaluate the degree of lake sediment contamination. As endpoints, developmental parameters (mortality, abnormality, heart rate, and hatching rate) as well as stress protein responses (hsp 70 levels) in the developing embryos were recorded during a 96-h exposure. Fertilized zebrafish eggs were exposed to both the whole as well as organic extract concentrations prepared from collected sediments from 5 sites along Laguna Lake, Philippines. Compared to whole sediment exposure, more severe embryotoxic and teratogenic responses were elicited in embryos exposed to organic extracts. However, since whole sediment-exposed embryos also revealed significant developmental defects, this exposure phase served as the more realistic exposure scenario in our study. Weak to strong upregulation of hsp 70 levels was also registered among embryos exposed to both whole sediments and organic extracts. The observed embryotoxic and proteotoxic responses by zebrafish embryos to Laguna Lake sediment exposures were discussed in relation to the analyzed contaminants in the sediments (heavy metals, PAHs (perylene), solvent). Overall, the present study points out that the sediment contact assay with zebrafish embryos offers a practicable and highly sensitive bioassay for the general assessment of sediment toxicity.