Bioenergy Lessons

Materials:

1. Paper plates = “lakes”; one per group
   
2. Goldfish Crackers: 2 bags
   
3. Straws = “fishing rods’: one per student
   
4. Small paper cups: 2 per group
   
5. Candy or stickers to represent “Goods” that can be purchased with extra fish.

1. Portion 24 Goldfish crackers into small paper cups ahead of time. Set up twice as many cups as the number of groups in the class.
2. Each group of 4 students gets 1 plate and 1 cup of Goldfish crackers. Each student gets one straw.

1. Each person must capture 2 fish for their family to survive.
   
2. If you catch more than 2 fish, you can sell them for other goods (a piece of candy, a sticker).
   
3. You will have 15 seconds to fish by using the straw to suck up the fish and place it outside of the lake. You may not use the straw to flick or rake the fish out of the lake.

What you don’t tell the students before the first round.

• The fish will reproduce after each round by doubling the number of fish in the lake.
  
• The maximum number of fish a lake can hold is 24. (Introduces the idea of Carrying Capacity)
  
• In order for the fish population to remain stable, there must be at least four fish in the lake. (Introduces the idea of Endangered Species).

What to Expect:

With the information given (and the information withheld), most groups will remove all of the fish they can in order to get a prize. (This introduces the idea of Overfishing.)

Go around and reward the individuals who got extra fish. 

Tell students to repopulate the lake by doubling the number of fish left in the lake. Most will not be able to do so.

Points of Discussion:

Renewable vs. Non-Renewable, Renewable vs. Sustainable, Carrying Capacity

Give the students a new population (the second set of cups that were prepared ahead of time) and pass out the student work sheet. Students should develop a plan of sustainable fishing.

At this point, students should be able to get 3 fish per person and still have enough fish to repopulate the lake and continue this way.

The following ideas could be implemented to make the activity more complicated by 

incorporating economics and population growth (both of the fish and the fishermen).

1. Add pretzel fish (a small number such as 4) to the original stock and make them worth 5 regular fish. However, for the population to grow, two pretzel fish must remain in the lake. Additionally, the two remaining fish will only produce one new fish each round. (This introduces the idea of population growth rates and that some species take a longer time to recover because of different reproductive and maturation rates.)
2. Use the Colored Goldfish crackers and assign different values to the colors. Start by placing an even number of each fish in the lake.

• Six Yellow/Orange: each worth $1
  
• Six Green: each worth $2
  
• Six Pink: each worth $3
  
• Six Purple: each worth $4
  

Set a monetary value needed for each person to survive ($6) and establish a Sales Chart for different goods (Candy: $1 for gross candy, $2 for good candy, $3 for great candy).

After each round, see who made enough money to live, and trade fish for goods. Repopulate the lake by doubling the fish numbers based on the color. (Example: After the round, 2 green, 6 yellow, 2 Pink, 2 Purple remain. Start the second round with 4 green, 12 yellow, 4 Pink, and 4 Purple.) If doubling the population results in more than 24 fish, then the fish that are worth more don’t repopulate. This rule is based on the idea that rarer organisms tend to grow more slowly and reproduce less than more abundant animals. Use elephants and mice as an example to explain this. Since elephants are larger and require more resources, they grow and reproduce slower than mice do. The same is true for fish. Smaller fish reproduce at a faster rate than larger fish.

As each round progresses, the population of each fish species (color) can be recorded and then graphed.

See Additional Student Sheet for follow chart, graph, and questions.