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Tuna for Lunch?

A Case Study Examining Mercury Bioaccumulation and Biomagnification

By Caralyn B. Zehnder

Tuna for Lunch?


 

Abstract

This case examines mercury bioaccumulation and biomagnification within the context of the human health impacts of ingesting food (specifically, fish) contaminated with mercury. It was inspired by a 2009 USGS report on mercury in fish, sediment, and water from streams across the U.S. The case is intended to help students make the connection between an environmental contaminant (mercury, a neurotoxin) and the food they eat. Human activities have been increasing mercury concentrations globally, and coal-burning power plants are the most common source of mercury pollution, a fact many students are unaware of. The case has been used in an introductory level environmental science class (predominantly non-majors), a non-majors general biology class, and a sophomore level ecology class (majors).

   

Date Posted

12/14/2010

Overview

Objectives

  • Explain why there are fish consumption advisories related to mercury.
  • Explain how mercury enters and moves through the environment.
  • Read, interpret, and apply scientific data presented in graphs and tables for this case study.
  • Define biomagnification and explain how it leads to higher concentrations of toxins in animals that are higher up the food chain.
  • Explore how biomagnification occurs in other systems and with other compounds (if students complete optional final activity).

Keywords

Biomagnification; bioaccumulation; mercury; neurotoxin; fish consumption; tuna; food chain; food web; trophic; coal-burning

  

Subject Headings

Biology (General)
Ecology
Environmental Science
Limnology
Public Health
Toxicology

EDUCATIONAL LEVEL

High school, Undergraduate lower division, Undergraduate upper division

  

FORMAT

PDF, PowerPoint

   

TOPICAL AREAS

N/A

   

LANGUAGE

English

   

TYPE/METHODS

Interrupted

 

 

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