Ecologically-Driven Exposure Pathways Science Team

Photograph showing white-faced ibis nesting at Bear River Migratory Bird Refuge, Great Salt Lake, Utah. U.S. Geological Survey (USGS) scientists evaluated a nonlethal method to estimate mercury in the embryos of 23 bird species using mercury content in eggshells. This method was effective for a wide range of ages and species.

(Credit: Josh T. Ackerman, Western Ecological Research Center. Public domain.)

Contaminant and pathogen exposure alone does not necessarily result in adverse health outcomes in fish, wildlife, or humans. There are numerous  pathways and processes that can alter the toxicity of naturally occurring and human-made contaminants in the environment.

The team uses their broad scientific expertise in hydrology, geochemistry, biology, and ecotoxicoogy to understand the complexities associated with the movement of toxicants and pathogens through the environment and within individual organisms. That information is used to determine how, where, and when exposure occurrs and if exposure results in health risks to wildlife and humans. 

Current Science Questions and Activities

• What are the various ecological factors, such as habitats and foraging strategies, that influence the pathways of contaminant exposure, health risks to fish and wildlife?

• What are the major intrinsic and extrinsic drivers of mercury exposure and risk to humans, fish, and wildlife at a global scale?

• What are the internal physiological determinants such as metababolism, transfer of mercury to offspring, changes in body mass, and molting that influence exposure and health risks in fish and wildlife?

• How do the internal factors differ among species and life stages?

• What are the Influences of landscape alterations, perturbations, and restoration on pathways and movement of contaminants through ecosystems and bioaccumulation into the food web of aquatic biota?

• Do multiple types and chemical mixtures have additive, synergistic, or antagonistic effects that influence the health of fish and wildlife?

• What are the internal and external drivers and regulators of human exposure to mercury?

• What is the risk of pathogen exposure and transmission among wildlife, livestock, and humans?

• What are the key environmental factors that control the viability of avian influenza virus shed by wild birds and what are the key environmental pathways of exposure and transmission of the virus?

• What is the role of soil, water, and vegetation in disease transmission such as Chronic Wasting Disease?

• How do invasive species influence the timing of contaminant uptake and bioaccumulation in fish and wildlife?