Name: _________________________________________________  Period: _______________


Purpose: Students will construct food chains and a food web for organisms of the Great Lakes.

Part I: Learning the terms

         Define the following terms

Producer (autotroph):


Consumer (heterotroph):




Trophic level:


Part II: Constructing the food chains


1.      The organisms on the blue sheets provided all belong to the Great Lakes ecosystem.

2.      Refer to the Menu on the back of this lab to learn about the feeding habits of the different organisms.

3.      Construct two food chains. One must consist of three organisms and the other should contain four organisms.  All food chains MUST start with a producer.

4.      Write the food chain in the space provided below.

EX: plankton forage fish eagle

5.      Draw arrows to show the flow of energy through the food chain.

6.      Label each organism as a producer or consumer.

7.      Label each of the trophic levels in the food chain.

FOOD CHAIN #1 (3 organisms)




FOOD CHAIN #2 (4 organisms)




HINT: Dont forget steps #6 and #7!!!!

Part III: Constructing the Food Web


1.      Use scissors to cut the organisms of the Great Lakes out keeping the name of the organism with the picture.

2.      Refer to the Menu to learn about the feeding habits of the different organisms.

3.      Organize ALL of the organisms into a food web onto the construction paper provided. (Hint: the producers should be at the bottom while the highest order consumers towards the top.)

4.      Draw arrows to show the flow of energy through the food web.

5.      Glue/tape everything in place once you are satisfied with your arrangement.

6.      Below each picture, label each organism as a producer, consumer or decomposer. NOTE: Label the dead plants/animals as both producers and consumers.

7.      Answer the questions that follow.


1.      What is the difference between a food chain and a food web?


2.      What do the arrows in the food chain/web symbolize?



3.      Why are there usually only 3 or 4 organisms in a food chain?


4.      Describe two abiotic factors that could affect the organisms in this food web.



5.      Describe two biotic factors that could affect the forage fish in the food web.


6.      What are the main producers in the Great Lakes Ecosystem?



7.      Would you expect there would be a greater number of eagles or forage fish in the ecosystem? Explain why.


8.      Place the following organism in the correct trophic level on the energy pyramid: eagle, plankton, herring gull, forage fish.






Eagle: consumes snapping turtles, salmon/trout, herring gulls, cormorants, forage fish


Salmon/Trout: consumes forage fish


Snapping Turtle: consumes forage fish, native mussels and other invertebrates


Humans: consumes snapping turtles, waterfowl and salmon/trout


Waterfowl: consumes plankton, vegetation, native mussels and other invertebrates


Forage Fish: consumes plankton, native mussels and other invertebrates


Cormorant: consumes forage fish


Herring Gull: consumes forage fish


Invertebrates: consumes plankton and bacteria/fungi


Plankton: most are photosynthetic


Bacteria/Fungi: feed off dead plants and animals


Native Mussels: consumes plankton and bacteria/fungi


Vegetation: photosynthetic