Health effects of pollutants in Pacific salmon

Use of Zebrafish to Assess Health Effects of Persistent Pollutants in Pacific Salmon

Building off work from the previous project “Effects of Salmon Omega-3 Fatty Acids on PBDE toxicity,” researchers used zebrafish as a low-cost model for studying the environmental and health hazards of toxic PDBEs.

Principal Investigator

Evan Gallagher, University of Washington, School of Public Health


Washington Sea Grant-supported researchers have been using zebrafish as surrogates to understand human exposure to PBDEs, develop new biomarkers for PBDEs and other emerging contaminants in fish models, and develop novel, cost-effective models for studying human risk. They completed a dietary exposure study in zebrafish subjected to a PBDE mixture relevant to salmon, initiated quantitative PCR analysis of gonadal gene expression, and conducted additional studies of PDBE effects in human cells.

Research Updates

Washington Sea Grant-supported researchers investigated the reproductive and behavioral effects of feeding PDBEs to zebrafish, a cost-effective surrogate species. They developed new high-throughput gene-expression technology to determine whether molecular biomarkers would better indicate reproductive injury. The researchers also studied PDBE-associated mitochondrial injury in human cells. Spin-off studies entailed measuring other contaminants of emerging concern in Puget Sound salmon and developing biomarkers to assess their effects.

High PBDE exposure caused minor damage to zebrafish reproductive tissues but no significant behavioral or molecular effects. However, related studies found that salmon harvested near wastewater treatment plants bioaccumulated numerous pharmaceutical and personal-care chemicals at levels harmful to other species. Investigators determined that omega-3 fatty acids found in salmon may provide chemoprotection against mitochondrial injury in human cells caused by PDBEs. These findings, together with other studies noting declining PDBE levels in the marine environment, suggest that other contaminants may be of more concern. Researchers shared these findings with educators, students, citizens’ groups and state and federal scientists.