Topic: Fisheries
Theme: Interactions

All life starts with energy from the sun. Through a process known as photosynthesis, plants change this energy into a chemical energy which is used to produce food. Plants are known as producers. Animals cannot produce their own food, so they must eat the plants. Animals are considered consumers.

There are three types of consumers:

  1. herbivores (animals that eat only plants),
  2. carnivores (animals that eat only flesh or other animals), and
  3. omnivores (animals that eat plants and other animals).

If a plant or animal dies before it is consumed (eaten), organismas known as decomposers break down the dead plant or animal tissue, thus returning nutrients to the environment like a fertilizer for plants to use to grow. The cycle of life goes on. This is known as a food chain.


  1. Find out all you can about marine (salt water) food chains. What is the relationship between a food chain and a food web? How are they "tied together?"
  2. Create a model of a marine food web using one of the methods below:
    • High Tech:
      • Search the internet for more information using key words for your search. Try Ocean Link: http://oceanlink.island.net Click on "Ocean Information" page, then click on "Food Web," or
      • Use the Visit to an Ocean Planet CD-ROM. Go to "Guide Map" Click on the large shooter marble "Life," then click on the smaller marble labeled "Systems & Interactions." Explore other areas on the CD ROM that pertain to your research.
      • Use Excel or Power Point and develop a flow chart depicting the food web. You may add relevant clip art to enhance your presentation.
    • Mid Tech:
      • Search the science section of the library for more information on marine food webs. Create a marine food web presentation using photocopies and/or transparencies.
    • Low Tech:
      • Search the science section of the library for more information on marine food webs. Using index cards, a hole punch, markers, and string/yarn, create a model of the food web. The string/yarn should be used to connect species with those they are dependent upon for food.
  3. Prepare a written explanation of the food web and the various food chains that may exist within it.


Your team will be assessed for accuracy in portraying the marine food web. You will be also be assessed on your presentation. For example, was it aesthetically pleasing, neat, organized in a way that is easily understood by the observer, and accurate.


Lesson Ideas created/adapted by Margaret Hammer (Graduate Research Assistant) and Judith Kenworthy (Technology Mentor Fellowship Associate) Texas A&M University. All comments and questions can be directed to stewart@ocean.tamu.edu