Estuary Food Pyramid

Coastal Ecology—Estuary Food Pyramid

Summary: When animals eat plants or other animals in order to survive, there is a flow of food energy through the ecosystem. What starts out as energy from the sun is converted into food energy by organisms that use photosynthesis, and is transferred to other organisms as they consume food. The layers of the resulting food pyramid, called trophic levels, represent available energy. In this activity, students will construct an example of a food pyramid for estuary organisms and examine this flow of energy.

Concepts to teach: Food pyramid, energy flow, trophic level

Goals: Students construct an example of an estuarine food pyramid to depict energy flow through trophic levels.

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Specific Objectives:

  1. There are three major categories of living organisms in an ecosystem and each has a special role. They are: producers, consumers, and decomposers
  2. The food energy produced by producers is cycled through the ecosystem through food chains and complex food webs by way of a series of energy levels called trophic levels.
  3. Energy is lost as it flows through the ecosystem. A food pyramid reflects fewer and fewer organisms at each level, supported by larger numbers of organisms at the trophic level just below.
  4. Students will learn that climate change has the potential for far reaching affects within marine food webs.

Activity Links and Resources:

  • Estuary Food Pyramid lessons from the NOAA Estuary Education website—Students build a food pyramid to examine the flow of food energy through the estuary ecosystem by placing organisms in the correct order on a food web energy pyramid.
  • Estuary Web of Life lessons from Padilla Bay National Estuarine Research Reserve address these essential questions:
    • How do the plants and animals in an estuary get energy to live and grow?
    • How are plants and animals dependent upon each other within a system?


  • Assessment included in the Estuary Education lesson.
  • Have students create their own Estuary web of life. Have them demonstrate their knowledge by including at least 1 producer, consumer and decomposer in their 6+ species web.
  • Compare estuarine food webs to freshwater food webs explored in Watersheds: Making the Connection topic guide