Students will study and replicate a model of the factors affecting fisheries populations in the Chesapeake Bay (or any other bay). Through a game they will investigate how decisions by watermen, recreational fisherpeople, and lawmakers influence and are influenced by economics and the abundance or scarcity of fish and shellfish stocks.


Students will:

  • Consider social, environmental, and economic impacts of overfishing from a variety of perspectives

Grade Level




abundance, aquaculture, depletion, harvesting, harvesting gear, moratorium, natural mortality, regulation, replenishment, scarcity, waterman


2 hours


For each student or pair of students:

For each group of six students:

  • Fishery Factor cards
  • Role cards and data charts
  • 2 open top containers (250 ml or larger bowls, shoeboxes, Tupperware)
  • 500 ml of dried pinto or small kidney beans
  • 1 graduated cylinder (250 ml or larger)
  • 4 measuring spoon sets (one per waterman and recreational fisherperson)
  • 4 cups (50 ml or larger) (one per waterman and recreational fisherperson)
  • 1 funnel with opening large enough to let beans through (or a piece of paper rolled into a cone)
  • Paper and pencils

National Science Education Standards

This activity supports the following National Academy of Sciences science education standards.

Grades 5-8:

  • Unifying Concepts and Processes - Systems, order, and organization
  • Unifying Concepts and Processes - Evidence, models, and explanation
  • Standard A: Science as Inquiry - Abilities necessary to do scientific inquiry
  • 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

Grades 9-12:

  • Standard C: Life Science - The Interdependence of Organisms
  • Standard E: Science and Technology - Understandings about science and technology
  • Standard F: Science in Personal and Social Perspectives - Population growth
  • Standard F: Science in Personal and Social Perspectives - Natural resources
  • Standard F: Science in Personal and Social Perspectives - Environmental quality
  • Standard F: Science in Personal and Social Perspectives - Science and technology in local, national and global challenges

National Social Studies Standards

This activity supports the following National Council for the Social Studies standards.

Middle Grades:

  • Standard III: People, Places, & Environments - h, k
  • Standard V: Individuals, Groups, & Institutions - e, g
  • Standard VI: Power, Authority, & Governance - c
  • Standard VII: Production, Distribution, & Consumption - f
  • Standard VIII: Science, Technology, & Society - d, e
  • Standard IX: Global Connections - d
  • Standard X: Civic Ideals & Practices - e

High School:

  • Standard III: People, Places, & Environments - h, k
  • Standard V: Individuals, Groups, & Institutions - e, g
  • Standard VI: Power, Authority, & Governance - c
  • Standard VII: Production, Distribution, & Consumption - f
  • Standard VIII: Science, Technology, & Society - d, f
  • Standard IX: Global Connections - d
  • Standard X: Civic Ideals & Practices - e


Whether the topic is catch restrictions on the blue crab or a moratorium on rockfish, fisheries management is almost always a contentious topic for citizens, scientists, watermen, lawmakers, and recreational harvesters alike. Yet, these groups want the same thing - populations of fish and shellfish that support and promise a viable future for our commercial and recreational harvesting industry.

Unfortunately, the scarcity of many of these resources makes polite cooperation difficult to achieve. When the devastating impacts of a hurricane, a more efficient harvesting gear, or a loss of habitat reduces populations, the resource may dwindle, but the demand for it continues to increase. The tough choices arising from this scarcity are the heart of current fisheries management.

In this activity, students grapple with these decisions through a game that illustrates how harvesting pressure, regulations, and other factors affect and are affected by the fisheries populations. By witnessing the rise and fall of populations in response to their actions and attempting to reach a compromise that is acceptable to everyone, students will gain an understanding of the challenge of fisheries management.

Before You Begin

  • Photocopy the Bottle Model Handout for each pair of students.
  • Collect and organize a set of materials for each group. This activity is written for groups of six to eight students. This group size will allow each student to have an active role in the game. However, if you wish to approximate more closely the real-life proportions of lawmakers, watermen, and recreational fisherpeople, you may want to play the game as a full class. To do this, you will need to modify the recommended starting population and harvesting levels described in the first step of the teacher procedures. Other options when you have an extra student or two in a group are to add an extra fisheries scientist or an additional lawmaker to serve as a DNR police person.
  • Photocopy one set of “Fishery Factor” cards for each group and cut each set into individual cards. Copy the card originals back-to-back so that the fronts of the cards read “Fishery Factor” and the backs have specific instructions.
  • In the game, students will assume the roles of several people whose actions influence fisheries. Photocopy one role card for each student and divide each playing group according to the following roles:
    • Lawmaker (one per group)
    • Fisheries scientist (one per group)
    • Watermen/commercial fisherpeople (at least three per group)
    • Recreational fisherpeople (at least one per group)

What To Do

  • Part 1
    Divide students into pairs. Distribute copies of the “Bottle Model” handout and instruct pairs to work together to complete the questions on the worksheet. The handout introduces the factors that influence fisheries populations. The rest of the activity is based on this student handout.
  • Part 2
    Walk your full class through the following sequence once. (These instructions are also provided to the students on the “Student Instructions” handout.
    • The goal of the game is to maintain a fishery that is stable enough to keep everyone in business for at least ten rounds.
    • Divide students into group of six to eight students. Give each group a set of student instructions. Also give each student a role card that explains his/her role in the game. Give each group a few minutes to explain and clarify their roles within the group.
    • Each group places between 300 and 400 ml of beans in one of their containers, which they should label “Bay”. The beans in this container represent the stock of beanfish in the Bay. The rest of the beans go in the second container, labeled “Extra”. To make the harvest more realistic, each group's Bay should be covered so that the harvesters cannot tell how much the stock has been depleted.
    • The game is played in ten rounds, each representing a year. In each round, the watermen and recreational fisherpeople “harvest” from the container abiding by current harvesting laws. For the first round, watermen are allowed to scoop three tablespoons of beans into their cup; the recreational fisherpeople (who each represent 25 fisherpeople) are allowed to take two tablespoons. These harvesting levels will change in subsequent rounds.
    • While the harvesters count their catch, the fisheries scientist calculates the reproduction of the species for the round and adds the appropriate quantity of beans to the Bay. For every one ml remaining in the container, the stock reproduces one ml.
    • Students (except the lawmakers) must record their actions for this round on a data sheet on the back of their job card. Each bean harvested is worth $100 for the first round. Once recorded, all harvests for the round can be emptied into the “Extra” container and used by the fisheries scientist when he/she replenishes the stock in future rounds.
    • After the first round, you can apply the effects of supply and demand to the game. If fewer than 150 beanfish are caught commercially then the price per fish rises to $110. If more than 210 beanfish are caught commercially, the price per fish falls to $90.
    • All harvesters and the fisheries scientists make verbal recommendations to the lawmaker as to the type and extent of regulations they feel should be in place in the upcoming year (round). The lawmaker records everyone's recommendation in his/her data sheet. When making recommendations or laws, students should consider the suggestions on their role cards. They should also remember that watermen need to make $6,000 each round or they go out of business.
    • Based on the recommendations, lawmakers make laws that must be followed by all harvesters in the next round.
    • The round ends with the lawmaker drawing a “Fishery Factor” card that introduces additional and unexpected occurrences. If the instructions on a card conflict with the lawmaker's decision, the instructions on the card override the lawmaker's decision. Otherwise, both card instructions and laws apply.
    • Repeat for ten rounds.
  • After ten rounds of the game, have the students (individually or in groups) answer the follow-up questions on the student handout for Part 3.

Suggestions for a smooth game:

  • Students may ask how to count broken or half beans. Any bean less than a full bean does not count toward the total; you may explain that these beans are under legal harvesting size.
  • Any bean that falls off the spoon during harvesting goes back into the pool and does not count toward the student's harvest.
  • To make sure that students are recording their harvests accurately, the fisheries scientist can count any person's harvest at any time. Anyone who has counted half beans or whose harvest is above the level recorded gets a $1,000 fine.
  • If the students in the role of recreational fisherpeople have trouble calculating the percentage of fisherpeople who caught more than one beanfish, suggest the following formula: % = (# beanfish caught - 25) x 4


The Bottle Model is only one representation of the way that replenishment and depletion influence a population. Ask students to draw and explain their own model of the way this process works.


  • Have students graph the data they collect (population and harvest) to investigate the following question: Does looking at harvest data really tell you how a species is doing? What are some of the problems associated with looking solely at harvest data when trying to determine the health of a species?
  • Explore the role of technology in sustaining fish populations.
  • Research and write about the influence of varying stakeholders on public policy.

Activity Handouts

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