Wildlife Toxicology

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Wildlife Toxicology
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Introduction

• Earliest type of environmental toxicology (Silent
  Spring hatched many new environmentalists --gt
  public most interested in wildlife toxicology
• Probably area of most true ecotoxicology - much
  of other environmental toxicology pays "lip
  service" to ecological mechanisms but wildlife
  toxicology often needs good knowledge of such
  mechanisms

• Arose from wildlife ecology instead of biomedical
  toxicology like most environmental toxicology

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Introduction (cont)

• Much work based on putting out "fires
• e.g Lake DeGray eagle die-off
• Newest fire in Arkansas external abnormalities
  in songbirds associated with Delta agricultural
  fields
• Craighead, Mississippi and Poinsett counties
• Normal abnormality rate 0.5
• Delta farm field abnormality rate 7-9

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I. Basic concepts

• Def. - Assessment of chemical hazards in the
  environment to wildlife populations
• A. Major foci
• 1. Assessing causes and mechanisms of problems
  in the field (dousing the fire)
• 2. Predicting potential adverse affects through
  experiments and testing.
• Note both above use laboratoy and field testing
• 3. Analytical chemistry - i.d. what is present
  and might be causing effect

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Basic concepts (cont)

• B. Exposure vs. Effect
• 1. Demonstrating exposure may be hard
• - tissue need to be sampled for "right stuff
• 2. " effect of exposure is harder
  (ex. PCBs
• detectable in all of us. Effect?)
• 3. Cause/effect or dose/response rare in
  unplanned wildlife contamination
• a. mostly infer from indirect evidence
• b. graded response in wildlife with changes in
  distance from source of contamination)

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II. Special Considerations in Wildlife Toxicology

• A. Definition of wildlife varies

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• B. Species response varies in
• 1. Habitat requirements
• 2. Activity patterns (when to apply pesticides
  --gt bluegill vs. bass)
• 3. Food habits (food chain considerations)
• 4. Detoxification mechanisms
• 5. Absorption pathways
• 6. Life stage sensitivities
• etc, etc.

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• C. Varied sources of stressors
• 1. Agrochemicals
• 2. Spent lead shot
• 3. Industrial waste
• 4. Acid precipitation
• 5. Irrigation
• 6. Mining
• 7. Logging

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Summary

• Wildlife toxicology is actually the single
  largest problem dealt with by environmental
  toxicology
• Lots being done, but a lot less than on standard
  test orgs (some changing --gt switching from
  Japanese quail to Bobwhite quail)

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