Deriving Field-Based Ecological Risks for Bird Species.

Area of Science:

• Environmental Toxicology
• Ecotoxicology
• Wildlife Ecology

Background:

• Ecological risks (ERs) are often assessed using lab-based bioassays, but their field relevance is uncertain.
• Field data linking bird breeding success to egg contaminant concentrations offer an alternative assessment approach.

Purpose of the Study:

• To develop a procedure for deriving species sensitivity distributions (SSDs) for birds using field data.
• To calculate ecological risks for p,p-DDE and polychlorinated biphenyls (PCBs) in birds using this novel field-based method.

Main Methods:

• Collected field data on p,p-DDE and PCBs egg concentrations and bird reproductive success from literature.
• Applied quantile regression (95th quantile) to fit exposure-response curves, accounting for external factors.
• Derived field-based SSDs and calculated ecological risks for the Great Lakes and Arctic regions.

Main Results:

• Ecological risks from combined p,p-DDE and PCBs exposure were 5-35 times higher in the Great Lakes compared to Arctic regions.
• Uncertainty in risk assessment was primarily due to limited field exposure-response data for bird species.

Conclusions:

• The developed method provides a robust approach for quantifying field-based ecological risks in birds.
• This method can be extended to other chemicals, species, and regions with sufficient monitoring data.