Title: Estuary Food Web
Learning Outcome:
Students will gain an understanding of how the environment and the organisms living in this
environment are interrelated.
Oregon Content Standard - Science:
4.2L.1 Describe the interactions of organisms and the environment where they live.
Materials Needed:
• Document camera
• Newsprint 18”x24” (1 per student group)
• Green pen (1 per student)
• Red pen (1 per student)
• Packet of markers (1 per student group)
• Yarn (it has to be long enough to create a web with the entire class)
• Estuary food cards (1 set per student group)
• Poster board 18”x24” (1 per student), size? 1 per student group
Activity Directions:
• Set Up: On the document camera, take one set of estuary food cards and go over what
each one represents. There will be a sun, phytoplankton or bacteria, plants, different
animals found in the estuary and finally a human.
Sample Food Chain Cards
Example organism card
Phytoplankton
Copepod
Nereid worm
3-spined stickleback
Kingfisher
Oligochaete worm
Role represented
Producer
Primary consumer/Herbivore
Secondary consumer/Omnivore
Tertiary consumer/Carnivore
Quaternary consumer/Carnivore
Detritivore
•
Open the discussion about how energy is transferred from the sun to the plants and
animals by asking:
o What is the difference between a producer and consumer?
o What is a carnivore?
o What is an herbivore?
o What eats both meat and plants?
o Why do carnivores, herbivores and omnivores eat?
o How does a plant get its energy to survive?
o What do bacteria do?
•
After class discussion, give each group of students a piece of newsprint and green pens.
Students will write FOOD WEB in the center of the paper. Ask them to write down
everything they know about a food web. Take pens away before continuing discussion.
Each group should be given time to discuss what they wrote down.
•
After the concept map and discussion, create a food chain on the white board with the
class to show the process of the sun’s energy moving from the sun to the plants, worm,
Activity developed and adapted by Carrie Munger stickleback, kingfisher and bacteria. During this process, ask students if more than one
thing eats the plants, insects and animals. Students should share their ideas with the
class and they should be added to the food chain. Students should realize that a food
web is a larger combination of many food chains, since things eat or get eaten by more
than one thing.
o What do plants need to get their energy?
Draw the sun and plants.
o Which way is the energy going?
Make sure the arrows are going towards the phytoplankton/plants.
o Who gets their energy from the phytoplankton or plants?
Students will say a lot of things, but insects or small crustaceans are the most important
answer here.
o What kinds of things eat copepods?
o What kinds of things eat worms and small fish like sticklebacks?
o What kinds of things eat kingfishers or herons?
This is a tough concept for students. After a kingfisher or heron dies, because they are at
the top of their food chain, their bodies can be scavenged by detritivores like worms or
decompose into the soil and decomposers (bacteria/fungi) are responsible for this.
o Do other organisms eat plants, copepods, or sticklebacks?
o This helps students understand that it is not a single chain, but many chains together form a
web.
•
Hand out estuary food cards. Have each group work together to create a food chain
with the cards by laying them out on the table. On the back of the newsprint on which
they created their concept maps, the students should be able to create a food chain by
drawing or writing the names of the animals found on the cards. Students should then
have the chance to add organisms that were found in the estuary, but not on the cards.
There should be multiple arrows leading from the smaller organisms to the larger ones.
This will demonstrate how a food chain is just a part of a food web and how animals can
be a part of more than one food chain. Allow time for students to show the class their
food webs and discuss what other organisms they added and why they added them.
•
Building food webs
o Each student needs to bring two estuary food cards and make a circle. Make sure
there are a few of each type of card brought to the circle. You will be the sun, so no
one needs to bring a sun card to the circle.
o Tell the students you are the sun and ask them what uses the sun for energy.
o Take the yarn and give the students that have plants and phytoplankton a piece of
the yarn. Create a visual food web with the yarn and the students as you discuss
what eats what (predator/prey) for energy.
o Once everyone is holding the yarn and you finished with the people cards, take a
pair of scissors and ask them what would happen if the plants and phytoplankton die
because we have destroyed the estuary habitat.
 What would happen if we build dams?
 What would happen to the _____________ if there was no longer a flow of fresh and
salt water?
 What eats_____________? So, now what would happen to this organism?
 What would happen if we pollute the water?
 What happens to the ________ if there are no _________ because the water is
polluted?
 How does this affect the estuary food web?
Activity developed and adapted by Carrie Munger o
o
o
•
Cut each connection of yarn and watch how quickly the food web crumbles.
Ultimately, this should be a good visual for the students to see how connected we
are to even the tiniest plant and phytoplankton.
A question to keep asking the students is, “What would happen if part of a food web
disappears?” A good followup question might be to consider different human
activities that could cause parts of the web to disappear... for example
Collect the pieces of yarn and estuary food cards.
Closing
Hand back the newsprint that the students previously used the green pens to write down
what they know about food webs. Using the red pens, have the students write down the
things they now know about a food web, particularly an estuary food web. They may
choose to add to their concept maps or correct/change comments they made earlier.
Assessment of Learning:
• Students should be able to name and identify organisms found in the estuary.
o Emerging students can name at least one organism found in the estuary, but may
also name organisms not found in the estuary.
o Students approaching mastery can name some organisms, but not all that would be
found in a food chain, or only focus on terrestrial or marine organisms without
recognizing that both play a role.
o Students who have mastered the concept can identify organisms from both terrestrial
and marine environments that could comprise a complete food chain in the estuary
and do not include non-estuarine organisms in their list.
• Students should be able to create a food web with the organisms found in the estuary.
o Emerging food webs will have connections drawn between organisms
o Food webs approaching mastery will demonstrate that the movement of energy is up
the food web by correctly labeling trophic levels and draw their arrows in the correct
manner.
o Students who have mastered the concept will produce webs with multiple
connections to different organisms and be able to demonstrate the role of
decomposers, while also correctly labeling the different trophic levels.
• Students should be able to identify possible outcomes if the estuary is destroyed.
o Emerging students can describe potential disruptions to the estuary but cannot
identify how those disruptions would affect organisms.
o Students approaching mastery can describe potential disruptions and identify direct
impacts of those disruptions on organisms.
o Students who have mastered the concept can describe potential disruptions and
identify both direct and indirect impacts of those disruptions on organisms.
• Concept maps can be compared between pre and post. Following the activity, students
should be able to add additional concepts and connections to their maps following the
activity and correct original misconceptions listed in the pre-activity maps.
Extensions:
•
•
Students can explore other environments and the organisms that live in these
environments, as well as human involvement in these environments.
Provide specific examples of environmental change to the estuary environment and
discuss how these changes might disrupt the food web
Activity developed and adapted by Carrie Munger •
Students can identify other kinds of materials (like chemical nutrients or pollutants like
mercury) that could pass through a food web or ecosystem and describe the interactions
that transfer or transform the materials.
Resources:
National Geographic Food Web Quick Flicks
http://magma.nationalgeographic.com/ngexplorer/0309/quickflicks/
Marine Food Webs
http://oceanworld.tamu.edu/resources/oceanography-book/marinefoodwebs.htm
Virtual Teacher’s Aide Food Web Lessons
http://www.vtaide.com/png/foodchains.htm
OPIHI Intertidal Food Web Building Activity
http://www.hawaii.edu/gk-12/opihi/extending/food.pdf
This lesson can be modified to meet the following standards
Interaction & Change
1.2L.1 Describe the basic needs of living things.
5.2L.1: Explain the interdependence of plants, animals, and environment and how adaptation
influences survival.
7.2L.2: Explain the processes by which plants and animals obtain energy and materials for
growth and metabolism.
H.2L.1 Explain how energy and chemical elements pass through systems. Describe how chemical
elements are combined and recombined in different ways as they cycle through the various levels of
organization in biological systems.
H.2L.2 Explain how ecosystems change in response to disturbances and interactions. Analyze the
relationships among biotic and abiotic factors in ecosystems.
Activity developed and adapted by Carrie Munger