A classroom game to demonstrate the balance of
life in the ocean.
Either directly or indirectly, almost every animal in the
ocean depends on microscopic phytoplankton for food. These
tiny plants form the base of nearly every food chain in the
ocean. Plants use energy from the sun to make their own food
through photosynthesis. In turn, some animals eat plants,
and other animals eat the plant-eating animals.
- Hand out the role cards and ask students to sit in a
circle wearing the card pinned to their shirt.
- Ask the students to identify which organisms rely
directly on the sun for their growth and nutrition. The
student that represents the sun holds a ball of yarn and
passes it to one of the members identified. For example,
if the plankton are identified as needing the sun for
nutrients, then the ball of yarn is passed to one of the
students labeled "plankton", while the sun continues to
hold the end of the yarn.
- Ask the students to identify which organisms rely on
plankton and repeat the questioning and passing of the
yarn until the each level of the web is identified.
Having the students describe their roles to the class
during the game will help build a better understanding of
the interdependence between roles in each web.
- Eventually, everyone will be all tided together in a
tangle of yarn. Some participants such as plankton may
have the ball of yarn passed to them as part of several
webs, indicating their importance to more than one
species in the ecosystem.
- Now cut the string at some point. The food web is
broken. What might happen to the various organisms in the
- What happens if a member of the web disappears
- Could any part of the web be replaced? If so, with
- Are any members of the web in competition with one
another? How and for what?
- How do people influence the food chain?