Island Explorers Curriculum Home


Unit 4

Lesson Plan 1

Lesson Plan 2

Lesson Plan 3

Lesson Plan 4

Lesson Plan 5


Concepts/Objectives | Vocabulary/Background | Activity | Extension


Lesson Plan 2




DDT Game


  • What are ways that poisons could get into the ocean and wetlands? (storm drain run off/urban streets, farm lands, industry, air pollution, sewage plants)
  • How do the poisons get into an animal? (gets into the food that it eats; direct instruction about sediments under the water absorbing chemicals)
  • Who can tell me how the food web works? (brief review; be sure predator/prey is understood)
  • Do you think that the poisons stay in the body of the animal or do you think that they leave? (stay there)
  • What do you think happens to the poisons when the small animal is eaten by a bigger animal? (they go into that animal too)

Let's play a game to see how this works:

Before You Start

  • Divide students into predator and prey groups.
  • For example: In a group of 35 students have at least 5 levels within the food web.
  • Example:
    12 zooplankton/crustaceans/ clams/worms, etc
    9 small fish
    7 medium/large fish
    5 birds (sea gulls)
    2 bald eagles


  • Animals can only "eat" the level below them. Students wear crepe paper ties--colored according to predator/prey level.
  • Be very clear who can "eat" whom.

To Play:
Students wear a color tie according to their animal group and play a simple walking tag game. Everyone starts off with 2 candies each in their bags. Teacher explains that this is a "safe" amount of DDT or toxins in the animal's system.

  1. Assign (or let students choose) their "roles" and wear the appropriate name tag name tag (sheet included).
  2. The lowest level: plankton, tiny shrimp, crustaceans, etc., have 2 candies in their bags and these students are the "prey". The next higher up predator group (example, "small fish") are "its predators." (NOTE trying not to use the word "taggers"). Playing walking tag game, predators must capture the crepe tie of the prey below their "trophic" level. When they "get" someone the predator "consumes" the prey's candies by adding those candies to the predator's bag. The prey then moves out of the group and sits down.
  3. Tagging continues until all the prey is caught.
  4. When the game is over the eagles have all of the candies.

Everyone except the sea gulls and eagles begin playing. Then the seagulls and eagles enter game as group gets smaller. (The game will take less than 5 minutes to play. Therefore, it can be played more than once.)


  • Students discuss who has the most candies/DDT. Is it too much to live, or to have healthy baby eagles?
  • What happens if there are no longer any healthy baby eagles being born? (the eagle population will die out)
  • How did the animal get so much DDT? (by eating the other animals)
  • Teacher explains the situation on Catalina Island.

Note to teachers: This is where background information should be presented.