LifeLines OnLine
2002 Summer Faculty Workshop
The Case:

Holy Starbucks Batman!

The DEQ reports that the Willamette River contains

measurable levels of caffeine.   Water samples were taken from Harrisburg, downstream from the Eugene water treatment plant and upstream from the city of Corvallis water intake facility.  Data indicates the caffeine levels are increasing from year to year.


Local fishing groups are concerned about the potential impact upon food species for migrating salmon fry.  "The caffeine may make them get to the sea faster, but if it kills their food sources then they are going to be awful hungry when they get there" stated an anonymous official.








Case Author: Stacey Kiser
Lane Community College

Case Analysis

How does caffeine get into rivers?

What do salmon fry eat?

What types of salmon fry food species live in this part of the Willamette River?

What are the effects of caffeine on the food species?  On the fry?

Should we do anything about caffeine in our river? 

Have students fill out a table like the one below:

What do you know?
What do you need to know?

Learning Goals

Goal(s):  Students will be able to

  • Identify field-collected invertebrates (at least to phylum).
  • Describe physiological differences and similarities across the invertebrate phyla in  selected organism system/systems.
  • Summarize and report potential impacts of a new environmental pollutant (caffeine) to an authority.


Investigations and Activities

Collect and identify potential salmon fry food species in the Willamette River.   

Potential link to chemistry:  Measure caffeine levels in Willamette River from water samples (or in Lane CC sewage lagoons).

Study effects of caffeine on California Blackworm (Lumbriculus variegatus) and water flea (Daphnia spp.)

Write preliminary report on the affects of caffeine on salmon fry food species to local city regulatory board.


Web sites:


maps, etc.

Student Products

Field notebook from collection field trip, including identification of organisms.

Laboratory report on effects of caffeine on invertebrates.

Report to regulatory board with adequate research support.

Assessment and Evaluation Plan

30 %  Field notebook and identification of sample organisms.

30 %  Laboratory report on effects of caffeine on invertebrates.

40%  Report to authorities.



Identify the specifics for using the cases in your classes.

Course name:
 General Zoology - Invertebrates
Likely sequence in syllabus:
 Capstone activity to quarter of invertebrate  diversity and comparative physiology.
Time during term:
 End of the term.
 1.5 weeks (9 classroom hours).
 Field and lab.
Students in course:
 Freshmen/Sophomore Majors.
Collaborative elements:
 Working in groups, sharing resources, group  meetings outside of class, group report writing.



Special thanks to Peter Woodruff for putting me on to the California blackworm.

LifeLines OnLine Home

Copyright 2002, LifeLines OnLine