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Activity Guide

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Activity Guide
Predators: Fishing for the Future


  • Explore the impacts of different fishing practices on habitats, by combining this activity with World Wildlife Fund’s Sharks in Decline. The activity includes active simulations of different fishing practices.


Through a fishing simulation, students model several consecutive seasons of a commercial fishery and explore how technology, population growth, and sustainable practices impact fish catch and fisheries management.


Students will:

  • Experience the “tragedy of the commons”1 as it relates to fishing resources.
  • Consider social, environmental and economic impacts of overfishing.
  • Identify sustainable fishing practices.


Social Studies, Biology, Environmental studies, Geography, Economics, Mathematics


aquaculture, bycatch, consumers, fertilizer, fisher, fishery, fisheries, species, sustainability, tragedy of the commons


1 hour


  • Plain M&Ms, one 14-ounce bag for up to 30 students
  • Peanut M&Ms, one 14-ounce bag for up to 30 students
  • Small cups, one per student
  • Serving bowls, medium size, one per group
  • Spoons, one per group
  • Straws, one per student
  • Watch, for timing activity
  • Copies of handouts (one per student): Fishing Log and Fishery Facts


This activity supports the following National Academy of Sciences Science Education Standards (Grades 5-8):

  • Standard C: Life Science—Populations and ecosystems
  • Standard F: Science in Personal and Social Perspectives—Populations, resources, and environments
  • Standard F: Science in Personal and Social Perspectives—Science and technology in society


Dr. Garrett Hardin coined the phrase “tragedy of the commons” in 1968. Hardin describes cows grazing on a common land. Since there is no direct cost to using the land, individual ranchers are motivated to add to their herds in order to increase their personal wealth. But each added animal damages the pasture a small, perhaps imperceptible, amount. Ultimately, this gradual degradation destroys the commons. Each rancher acting alone is behaving in an appropriate, rational manner, yet the sum total of all the ranchers’ actions destroys the resource for them all.

From 1950 to 1990, there was a fivefold increase in the world annual fish catch. An increasing demand for fish coupled with environmentally damaging fishing practices are leading to another tragedy of the commons. Roughly 70 percent of the planet’s marine stocks are fully or over exploited, according to the Monterey Bay Aquarium’s Seafood Watch program.

In this activity, students will simulate fishery activity in different oceans. As students progress through the fishing seasons, they will likely overfish their oceans and will have to migrate to other oceans to meet their basic needs. Most groups will eventually create a total crash of fish stocks in all the oceans. This demonstration will clearly indicate the benefits of sustainable fishing practices.


1. Check for peanut allergies in your class. You can do the activity using only plain M&Ms, if necessary.

2. For a class of 20, you will have five or six groups of three to four students each. Each group will start with 20 plain and 10 peanut M&Ms. Count out the first round of M&Ms for each group, and place them in cups or bags.

3. Copy the Fishery Facts and Fishing Log handouts.

4. As a pre- or post-activity reference, have students read the handout Fishery Facts . For additional references, read Chapter 5 “Global Trends—Food, Water, and Income” and Chapter 6 “Environmental Sustainability” from Facing the Future’s publication Global Issues & Sustainable Solutions. www.facingthefuture.org


1. Introduce and discuss the concept of sustainability using the following definition:

Sustainability is meeting the needs of the present without compromising the ability of people, other species, and future generations to survive.*

Ask why sustainability might be an important goal for a society and what might be difficult about realizing this goal.

2. Tell students that today they are going to go fishing and explore some of these sustainability issues.

3. Explain the game rules:

a. Each student will be a “fisher” whose livelihood depends on catching fish.

b. Peanut M&Ms represent the largest and most valuable fish (tuna, swordfish, et cetera).

4. Plain M&Ms represent the next most-valuable fish (cod, salmon, et cetera).

a. Each fisher must catch at least two fish (large or small) in each round to survive (i.e., get enough fish to either eat or sell).

b. When the fishing begins, students must hold their hands behind their backs and use the “fishing rod” (straw) to suck “fish” (M&Ms) from the “ocean” (bowl) and deposit them into their “boat” (cup).

c. The fish remaining in the ocean after each fishing season represent the breeding population, and thus one new fish will be added for every fish left in the ocean (bowl).

5. Divide the class into groups of three or four students and have each group choose an ocean name such as North Atlantic, North Pacific, Arctic, Mediterranean, et cetera.

6. Give each group one serving bowl and each student one small cup, one straw, and one copy of the handout Fishing Log .

7. Put 20 plain and 10 peanut M&Ms in each group’s bowl.

8. Say “start fishing” and give the students 20 seconds for the first “season” of fishing.

Remember for this round, students should hold their hands behind their backs.

9. Have each fisher count his or her catch (M&Ms in their cup) and record the data in their Fishing Log .

10. After every round, fishers who did not catch the two-fish minimum must sit out for the following round.

11. Add one new fish for every fish left in the ocean (bowl).

12. Allow remaining fishers to use their hands on the straws during the second session to represent “new technology.”

13. After the second fishing season, give one fisher from each group a spoon that they can use instead of their straw. This represents more new fishing technology such as trawl nets, sonar equipment, et cetera. Continue the game for Round 3.

14. Ask, “What happened when ocean group [name] ran out of fish? How are the fishers going to survive now?” (One option is to move to another ocean.) Allow students to “invade” other ocean groups when their ocean is depleted, but do not tell them that they can do this beforehand. Fishers may either go as a group to another ocean or they may disperse to other oceans.

15. Repeat fishing, recording, and replenishing fish stocks until either sustainable fishing is achieved or until all (or most) groups fish out their ocean.


1. Have students write their thoughts about the following quote by John C. Sawhill, relating it to the fishing activity. “ John Sawhill is the former President and Chief Executive Officer of The Nature Conservancy.

“In the end, our society will be defined not only by what we create, but by what we refuse to destroy.”

2. Use the following sample questions to lead a discussion about the activity:

  • How did you feel when you realized that you had depleted your fish stock?
  • How did you feel when other fishers joined your ocean group?
  • How does this activity relate to real ocean and fishery issues?
  • What is missing in this game? (Answer: Impacts to non-human animals that rely on fish for their survival, population growth, et cetera.)
  • What happens to a resource when you have infinite population growth, growing technology, and a finite resource?
  • Are there any commonly owned resources in our region or community? If so, what are some similar issues around them, and how can the resources best be managed? (Answer: Air is a commonly used resource-how do we deal with air pollution? Forestry or animal grazing rights also sometimes create similar discussions. You might also talk about city and national parks, and other public lands, and the competing uses and needs.)

3. Have students brainstorm ways to have a sustainable fishery. What rules could be developed? (For example, limits on type of equipment allowed, amount and type of fish, shorter seasons.)


Read Garrett Hardin’s essay “The Tragedy of the Commons” and discuss how it is reflected in this game. For a downloadable version, go to www.garretthardinsociety.org/articles/art_tragedy_of_the_commons.html

Needs Improvement—In the reflection discussions, student cannot relate the John Sawhill quote to the activity and/or cannot develop any rules for sustaining a fishery. Student fails to connect “The Tragedy of the Commons” to the fishing activity.

Satisfactory—In the reflection discussions, student cites at least one way in which the John Sawhill quote is reflected in the fishing activity and participates in the remaining discussions. Student captures the essence of “The Tragedy of the Commons” as reflected in the fishing activity and support the argument with at least one example.

Excellent—In the reflection discussions, student cites one or more ways in which the John Sawhill quote is reflected in the fishing activity and participates actively in the remaining discussions. Student clearly articulates how the fishing activity reflects “The Tragedy of the Commons” and supports the argument with one or more examples.


  • Repeat the activity after the class has experienced the “tragedy of the commons” and discussed sustainable practices to see if they can harvest in a sustainable manner.
  • Students can research which fish are harvested in a sustainable manner and which are being depleted. Have them do an advertising campaign in their school promoting the consumption of sustainable fish and avoiding the consumption of threatened fish. (This might include researching the kind of fish served in your school cafeteria, developing a system that protects threatened fish, and presenting it to your cafeteria staff, principal, and school board.) For recommendations about which seafood to buy or avoid, check out the Monterey Bay Aquarium’s Web site “Seafood Watch” at www.montereybayaquarium.org or the Audubon Web site seafood.audubon.org/.
  • Have students research a local fishery and include interviews with local fishers, biologists, and other people involved with the fishery.
  • Have students choose one of the major world fisheries, such as salmon, cod, or tuna, and develop a sustainable fishing plan, paying attention to international laws and treaties.
  • Have students investigate fish farming and its environmental and economic impacts.
  • Have students research federal and state laws relating to economic use of public lands by private companies and individuals. Determine whether these laws balance environmental protection and economic development. If not, outline new laws to create such a balance.
  • Do a watershed planning/protection project to help protect fisheries from environmental damage.
  • Participate in a beach or river cleanup project.
  • Join an Ocean/Fisheries Action Network such as:


Visit the United Nations Food and Agriculture Organization Fisheries Resource Web site at www.fao.org/fi .

For information and pictures about the state of the world’s fisheries, see the New International Magazine’s online issue on fishing at www.newint.org/issue325/facts.htm .

To explore sustainable seafood choices, visit the Seafood Watch Web site at www.mbayaq.org/cr/seafoodwatch.asp or The Marine Stewardship Council (MSC), an independent, non-profit organization that promotes responsible fishing practices. www.msc.org

Seafood Network Information Center is a clearinghouse for sharing seafood knowledge. seafood.ucdavis.edu/


“Fishing for the Future,” © by Facing the Future: People and the Planet, www.facingthefuture.org 2004 (used with permission). Adapted from Fishing with Jim by teachers Jim Hartmann and Ben Smith.

Note to Teachers: This lesson and others relating to National Geographic’s Strange Days on Planet Earth can be found online at www.pbs.org/strangedays/

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