Photo: Great Lakes Fishery Commission
What is the most effective method to reduce sea lamprey (Petromyzon marinus) populations?
|Grade Levels||Grades 9-12|
learning, data interpretation, earth systems interactions, decision
analysis, exotic species
This activity complies with National Science Education Standards, with emphasis in science as inquiry, science in personal and social perspectives, life science, and history and nature of science.Ohio Standards
Earth and Space Sciences:
Grade 11 Earth Systems
Grade 11 Diversity and
Interdependence of Life
Grade 12 Diversity and
Interdependence of Life
Grade 9 Abilities to
Do Technological Design
Grade 11 Understanding
Grade 10 Doing
Grade 11 doing
Scientific Ways of
Grade 11 Science and
Grade 12 Science and
|Length of Activity||1-2 class periods|
|Materials Needed||Internet access
(or you can print out fact sheets), student handouts
|Prior Knowledge Needed||Exotic Species, Great Lakes fauna, food web|
When completed the student will be able to:
lamprey is a parasitic fish that is native to the Atlantic Ocean and many of
its tributaries. The sea lamprey invaded the Great Lakes region in the
early 1900’s via the Welland Canal. The sea lamprey feeds on fish by
attaching to the host with a sucking and boring a hole into the skin of the
fish using sharp teeth. The sea lamprey
will drain the body fluids from the host fish. This generally results in the
death of the fish either through direct feeding or from infection to the
wound created. Efforts to control the sea lamprey populations have been
in effect since the early 1960’s. Methods for control include mechanical and electrical wires
to shock the lamprey, and the use of
a lampricide, a toxic chemical. Today there are many options for the
management of lamprey populations, however, not one technique has resolved
the problem completely.
Decision analysis is a scientific way of assessing alternatives, judging alternatives, and forecasting consequences of the alternatives. The method of decision analysis includes a series of steps based on the "PrOACT" model:
1 = Define the Problem;
The goal of this activity is to use decision analysis in order to determine which method of reducing sea lamprey would be the most effective.
1. Have the students briefly do research about the issues and problems surrounding the arrival of the sea lamprey to the Great Lakes.
2. Discuss the progression of making a decision according to the steps outlined in the Background Information section. Have students do research about lamprey control methods (available online at http://www.glfc.org/sealamp/how.asp). Discuss the students' findings, and review the selection of options.
Option 1 = No Future Treatment (there is no information/fact sheet for this
option. Students will have to think about possible consequences of no
3. In groups of three to four students, establish 4 objectives by which to evaluate the options. The objectives should be guidelines to be followed to choose an option (for example, possible objectives could be “to achieve target sea lamprey population levels of 5 mating couples per spawning area” or “to maximize economic values of reduction options.”) Management objectives are those actions that are specifically related to the problem, can be measured, and have a specified amount of time.
4. Of the objectives written, weigh the objectives in terms of importance and value. Assign a value of 1 to 10 for importance, with 10 indicating the most important. Take into consideration tangible and intangible values.
5. Read about each population reduction method and critically evaluate each method for possible consequences. PDF student worksheet available for download.
6. Groups should discuss the tradeoffs they are willing to make for each alternative. What is negotiable? What parts of the alternatives are they willing to give or take? Are some consequences negotiable?
7. As the final step, students will decide which reduction method they would choose based on the evaluations of objectives, alternatives, consequences, and tradeoffs. Students can create a table (using student worksheets) to compare the alternatives.
The Adobe Acrobat reader (for opening .pdf files) can be downloaded (free) at http://www.adobe.com/products/acrobat/readstep2.html
activity with a roundtable discussion regarding the results:
students assume the role of a biologist (or any other interested party) and
write a letter to the governor with their recommendations. Be sure to
include the methodology for the conclusion!
student group a specific constituency. One group may represent sport
anglers, another commercial fishers and another group may represent the
locals who have resided in the area for many years, are the results the
|References & Resources||Great Lakes
Fishery Commission Sea
National Science Education Standards, http://www.nap.edu/html/nses/html/
Exotic Aquatics on the Move, http://www.iisgcp.org/EXOTICSP/
|Sara White, High
School Earth Systems Teacher, Ohio
The Ohio State University School of Natural Resources, 2003
Web assistance by Jennifer Raab and Ann Froschauer
to list of Lessons
Go to Student Page