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Updated: Aug 8, 2026
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Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey
Published on: August 29, 2014
CONCENTRATION‑DEPENDENT TROPHIC TRANSFER OF SELENIUM TO BIRD EGGS: FIELD SYNTHESIS AND LABORATORY BENCHMARKS
Gary M Santolo1, Harry M Ohlendorf1
1Jacobs, 2485 Natomas Park Drive, Suite 600, Sacramento, CA 95833.
Integrated Environmental Assessment and Management
|August 6, 2026
Summary
Maternal selenium transfer to bird eggs varies greatly. Understanding diet-to-egg transfer factors is crucial for assessing reproductive risks from selenium exposure in avian wildlife.
Area of Science:
- Environmental Toxicology
- Avian Ecology
- Biogeochemistry
Background:
- Maternal selenium transfer is a key pathway for avian reproductive risk.
- Diet-to-egg transfer of selenium is highly variable, influenced by species, diet, timing, and selenium form.
Purpose of the Study:
- To quantify diet-to-egg trophic transfer factors (TTFs) for selenium in birds.
- To evaluate the concentration dependence of selenium transfer.
- To develop a conceptual model for selenium transfer and provide practical guidance for risk assessment.
Main Methods:
- Synthesized paired diet-egg datasets from field studies (wetlands and terrestrial systems).
- Analyzed controlled laboratory feeding studies with defined selenium sources.
- Utilized compartment analysis to differentiate selenium uptake dynamics in albumen and yolk.
Main Results:
- Field studies showed variable TTFs, often low (≤1), especially with invertebrate or fish diets exceeding screening levels.
- Laboratory studies with selenomethionine diets yielded higher, more consistent TTFs, indicating high bioavailability.
- Albumen selenium reflects recent intake, while yolk selenium integrates exposure over longer periods, explaining data variability.
Conclusions:
- A three-zone model (deficiency, regulation, high exposure) describes selenium transfer, with damping in the regulation band.
- Operational guidance is provided for sampling prey (pre-laying window), considering selenium speciation (selenomethionine), and using appropriate TTFs.
