What is the most effective method to reduce sea lamprey (Petromyzon marinus) populations?

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.

Earth and Space Sciences:
Grade 10 Earth Systems
6. Describe ways that human activity can alter biogeochemical cycles, food webs, and energy pyramids.

Grade 11 Earth Systems
12. Explain ways in which humans have had a major effect on other species.

13. Explain how human behavior affects the basic processes of natural ecosystems.

Life Sciences:   
Grade 10 Diversity and Interdependence of Life
15. Explain how living things interact with biotic and abiotic components of the environment.

16. Relate how distribution and abundance of organisms and populations in ecosystems are limited.

18. Describe ways human activities can deliberately or inadvertently alter the equilibrium in ecosystems.

Grade 11 Diversity and Interdependence of Life
6. Predict some possible impacts of an ecosystem with the introduction of a non-native species.

9. Give examples of how human activity can accelerate rates of natural change and can have unforeseen consequences. 

Grade 12 Diversity and Interdependence of Life
8. Based on structure and stability of ecosystems and their nonliving components, predict the biotic and abiotic changes in such systems when disturbed. 

Science and Technology:   
Grade 9 Understanding Technology
1. Describe means of comparing the benefits with the risks of technology and how science can inform public policy. 

Grade 9 Abilities to Do Technological Design
2. Identify a problem or need, propose designs and choose among alternative solutions for the problem. 

Grade 11 Understanding Technology
2. Predict how decisions regarding the implementation of technologies involve the weighing of trade-offs.

3. Explore and explain any given technology may have a different value for different groups of people and at different points in time. 

Scientific Inquiry:  
Grade 9 Doing Scientific Inquiry
5. Develop oral and written presentations using clear language, accurate data, etc.

6. Draw logical conclusions based on scientific knowledge and evidence from investigations.

Grade 10 Doing Scientific Inquiry
2. Present scientific findings using clear language, accurate data, etc.

4. Draw conclusions from inquiries based on scientific knowledge and principles, use of logic and evidence (data) from investigation.

Grade 11 doing Scientific Inquiry
5. Summarize data and construct a reasonable argument based on those data and other known information.

Scientific Ways of Knowing:  
Grade 11 Nature of Science
2. Apply scientific inquiry to evaluate results of scientific investigations.

Grade 11 Science and Society
8. Explain that the decision to develop a new technology is influenced by societal opinions and demands and by cost-benefit considerations. 

10. Describe costs and trade-offs of various hazards.

Grade 12 Science and Society
8. Recognize that individuals and society must decide on proposals involving new research and the introduction of new technologies into society.

9. Recognize appropriateness and value of basic questions “What can happen?” etc.

10. Recognize that social issues and challenges can affect progress in science and technology.

When completed the student will be able to:

• describe what the sea lamprey is, analyze its threats to the freshwater ecosystems of the U.S. and discuss how the sea lamprey was introduced into U.S. water systems. 
  
• use the PrOACT method of decision making to evaluate sea lamprey control techniques. 

Background

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:

Step 1 = Define the Problem;
Step 2 = identify and agree upon management Objectives to achieve; assign weights to the objectives;
Step 3 = determine probable Alternatives
Step 4 = forecast Consequences of the options; and
Step 5 = consider the Tradeoffs and use the model to rank each option. 

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.

Procedure

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 treatment!)
Option 2 = Barriers
Option 3 = Sterile Male Release
Option 4 = TFM

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

1. What options were chosen with greater frequency? Why?
   
2. What were the factors that led the group to the weights assigned?  What was compromised?
   
3. Do the numbers always correlate with the thoughts/feelings of the group?  What do the numbers represent?
   
4. As a class, determine the best options. 

Evaluation

Have the 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!

Extension Activity

Assign each 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 same?

• TFM fact sheet
  
• Sea lamprey barrier fact sheet
  
• Sterile male release fact sheet

National Science Education Standards, http://www.nap.edu/html/nses/html/

Exotic Aquatics on the Move, http://www.iisgcp.org/EXOTICSP/

The Great Lakes Sea Grant Network has produced a game about lamprey survival entitled "Beat the Barriers"

Author(s)