Food Chains and Webs

Food Chains and Webs 

Teacher's Guide 

AGC/United Learning 1560 Sherman Av., Suite 100 Evanston, IL 60201 1-800-323-9084 

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catalog # 2696 

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AGC/United Learning 1560 Sherman Av., Suite 100 Evanston, IL 60201 1-800-323-9084


Grades 5-8 

Viewing Time: 21 minutes 

Program Summary 

Take your students on a tour of the food chain in this video designed 

for students in grades 5 through 8. Come along on an 

expedition with Dr. Brian Jerome as he visits Vermont's White 

River Watershed, its flowing waters, forests, wetlands, and rocky 

shores to examine how energy and matter are transferred through 

the environment. He will explore the relationships between producers 

and consumers, predators and prey, and biotic and abiotic 

factors. Students will learn about food chains and webs by studying 

the interactions of the plants and animals of this region. 

Through this video students will learn why food chains and webs 

are important in their daily lives. 

Dr. Brian Jerome takes students on a live-expedition to the White 

River in the Green Mountains of Vermont. In his quest to catch a 

trout, he shows students the interactions of the many plants and 

animals on the river. Footage includes extensive shots of the 

numerous plants in this riparian ecosystem. Plants and animals 

featured in the video include phytoplankton, cattail, sumac, maple 

and birch trees, and pines, as well as moose, deer, hawks, trout, 

nymphs, snakes, squirrels, and bears. The intricate web of life is 

discussed by illustrating the interactions of these many organisms. 

The video is vocabulary-rich and uses key terminology, such as 

ecosystem, producer, consumer, predator, phytoplankton, herbivore, 

carnivore, biomass, trophic level, and biomagnification. 

Definitions for these terms are provided in the video and are also 

displayed on the screen. 


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Numerous colorful and easy-to-understand graphics greatly enhance 

student understanding of the key concepts involved with 

food chain and webs. Illustrations of food chains, food webs, 

energy pyramids, biomass pyramids, and energy loss highlight 

real-life examples along the White River. 

In addition, the negative effects of pesticides on the food chain 

are highlighted through a discussion of Rachel Carson's crusade 

to end the use of DDT. Positive steps toward revitalizing food 

chains are also examined through a look at the Atlantic Salmon 

Restoration Program on the White River. 

Student Objectives 

After viewing the video and completing the lessons and activities, 

students will be able to… 

• Provide examples of the plants and animals that live in an ecosystem 

such as the White River riparian ecosystem. 

• Define the vocabulary words addressed in the video and in the 

Word Search Activity. 

• Describe how producers are at the base of most food chains and 

webs. 

• Given several organisms, arrange them correctly in a food chain 

or food web. 

• Define and identify herbivores, carnivores, and omnivores in a 

food chain or web. 

• Describe the role of decomposers in food chains and webs, and 

how they promote the cycling of matter. 

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Teacher Preparation 

Before showing this program to your students, it is suggested 

that you preview the video, and review this guide. Duplicate any 

blackline masters you wish to distribute. 

Decide with which concepts and vocabulary students may be 

unfamiliar, and review this information prior to showing the video. 

It should be noted that there are a large number of organisms 

which participate in food chains and food webs. The types of 

organisms largely depends on geographic location. Student exposure 

to various organisms may vary widely depending on where 

they live, and their awareness of the natural world. 

No matter where they live, plants and animals form some type of 

food chain or web. Attempt to make students aware of the organisms 

in their neighborhood, and how they interact with each other 

by discussing them before viewing the video. 

You may decide to duplicate and distribute some of the blackline 

masters so that students can reference them during the video program. 

You are encouraged to tailor the video and accompanying 

blackline masters to the needs of your students, and your instructional 

needs. It is hoped that the video and blackline masters 

serve as a starting point for additional discussion and learning 

about this fascinating topic. 

The video presentation is followed by a Video Quiz. The questions 

from the video quiz may be used as a pre-test to gauge student 

comprehension. These questions appear on Blackline Master 

1, Video Quiz. The answers appear in the Answer Key on 

page 8. 


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Introducing the Video 

Before showing students the video you may want to discuss with 

students the needs of living things. Discuss that living organisms 

need energy to carry out functions. Also, discuss how living 

organisms go about obtaining or producing organisms. Highlight 

the differences between plants which produce their own food, 

and animals which must eat plants or other organisms to obtain 

their energy. 

Students may not be familiar with much of the terminology in 

the video. You may want to review the spelling and pronunciation 

of terms, such as consumer, producer, photosynthesis, carnivore, 

herbivore, biomass, and energy. You also may want to discuss 

the meaning of many of these terms. 

The majority of the video was filmed on location in central Vermont. 

Point out to students on a United States map the location 

of Vermont. On a more detailed map of New England you may 

want to point out the location of the White River, running from 

above Rochester, Vermont to its confluence with the Connecticut 

river near White River Junction, Vermont. Point out the eventual 

mouth of the Connecticut River in Long Island Sound. 

Ask students what they think a "food chain" is. Do they play a 

role in food chains and webs? If so, what role(s)? Compare their 

answers to these questions before and after participating in the 

lesson. 

Present the video. The viewing time is 21:00. 

Follow-Up Activities 

Discussion 

Following the video, students may have additional questions. 

Allow time for students to air their questions. Avoid answering 

the students' questions directly; ask them additional questions 

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leading them to the answers on their own, or encourage other 

students in the class to answer questions. 

There are numerous issues which may warrant further questions. 

As a class you may want to discuss the following: 

• What is an ecosystem? What ecosystems are located in your 

area? 

• What are the differences between producers and consumers? 

What are some examples of each in your area? 

• Why in healthy ecosystems, does there tend to be a much greater 

biomass of producers than consumers? 

• Some people argue that one of the ways to battle world hunger 

and to provide a greater amount of food to a growing world population, 

is to encourage people to eat more producers, such as fruits 

and vegetables. Discuss the issue in terms of energy loss along 

the food chain. 

• Discuss the plants and animals that make up the food web immediately 

surrounding the school. Create a diagram on a chalkboard 

or overhead. 

• What are some examples of food webs that are badly damaged 

by either animal extinction or the introduction of exotic organisms 

into the food web? Discuss how this affects other organisms 

in the food web. 

Field Trip Opportunities 

Depending on the part of the country in which you reside, there 

may be many opportunities to take your class on field trips to 

sites which highlight food chains and webs. There may be natural 

areas or parks close by where students can observe the plants 

and animals which make up food chains and webs. Schools in 

urban environments might be able to visit a park or playground 

where they can observe food chains or webs in action. 


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Local science museums may have exhibits describing food chains 

or webs. It might also be interesting to visit a grocery store or 

school cafeteria where students can see how the foods they eat fit 

into food chains and webs. Here they could create food chain 

and web diagrams from common everyday foods. 

Topics for Further Research 

The following topics would make good topics for research 

papers, plays, creative writing exercises, and art projects: 

• How have food webs changed over the past 200 years in your 

region? 

• Describe the role of pesticides and other toxins in food webs. 

• Read and report on Rachel Carson's book Silent Spring. 

• Chose a part of the world under severe environmental degradation, 

such as the rain forests of Central and South America, and 

create diagrams of food webs before and after deforestation. 

• Write a song or poem about a food web in the area. 

• Take photographs or draw pictures of animals in a food web 

from which a bulletin board display can be made. 

• Investigate how habitat enhancement can change the interactions 

of organisms in food webs. 

• Compare and contrast food webs in different ecosystems, such 

as between a deep ocean ecosystem and a prairie ecosystem. 

Blackline Masters 

Answers to all Blackline Master activities appear in the Answer 

Key on page 8. 

• Distribute Blackline Master 1, Quiz. The questions on this 

sheet replicate the questions in the Video Quiz at the end of the 

presentation. You may use it as a pre-test and/or post-test to gauge 

student comprehension. 

• Distribute Blackline Master 2, Chaining It Together. This 

activity provides students with the components of a simple uni- 

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directional food chain to model. It also asks that they identify 

consumers and producers, as well as trophic levels, within the 

food chain. 

• Distribute Blackline Master 3, Web Weaving. This activity 

provides students with the components of a more complicated 

multi-directional food web to model. It also asks that they add 

decomposers to the model, and that they identify how this food 

web may be different from those found in their region. 

• Distribute Blackline Master 4, Word Search, a fun activity 

that asks students to locate hidden vocabulary words. 

• Distribute Blackline Master 5, Vocabulary Words and Definitions. 

This exercise asks students to provide definitions of the 

vocabulary words fundamental to the program. 

• Distribute Blackline Master 6, Field Form For Food Webs, 

provides students with a chart to complete based on the organisms 

indigenous to your region. Once organisms have been identified 

as consumers or producers, from where they derive their 

energy, and for whom they serve as food, students are asked to 

incorporate them into a food web diagram. 

• Distribute Blackline Master 7, The Big Picture. This exercise 

asks students to think of the cycling of matter and the flow of 

energy in food webs. It also asks that they define and examine 

biomagnification as it applies to the introduction of harmful 

chemicals into ecosystems. 

• Distribute Blackline Master 8, Name That Critter, asks students 

to identify several anonymous organisms based on clues, 

and to identify the organisms as producers or consumers, and as 

herbivores, carnivores, or omnivores. 


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Answer Key 

Blackline Master 1, Video Quiz 

1. ecosystem 

2. producers 

3. consumers 

4. carnivores 

5. web 

6. trophic 

7. matter 

8. decomposers 

9. heat 

10. less 

Blackline Master 2, Chaining It Together 

1. Student diagrams of the food chain should look similar to the 

following: 

2. Student diagrams should look like the above with phytoplankton 

labeled producer, and all other organisms labeled consumer. 

3. The food chain should be labeled as follows: Phytoplankton - 

First Trophic Level, Nymph - Second Trophic Level, Trout - Third 

Trophic Level, Heron - Fourth Trophic Level 

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Blackline Master 3, Web Weaving 

1. Student diagrams of the food web should look similar to the 

following: 

2. Student diagrams should look like the above with decomposers 

added. 

3. Student answers will vary depending on location. 

Blackline Master 4, Word Search 


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Blackline Master 5, Vocabulary Words and Definitions 

1. Food chain - a diagram illustrating the feeding relationships 

of organisms, shows how energy and matter are transferred 

through the environment 

2. Ecosystem - the living and non-living things interacting in the 

environment in a certain place 

3. Riparian - a river or stream-based ecosystem 

4. Producer - an organism that makes its own food; plants are 

producers 

5. Consumer - an organism that needs to eat other organisms for 

its food 

6. Herbivore - an organism that eats primarily plants 

7. Carnivore - an organism that eats primarily other animals 

8. Prey - an organism that serves as food to another organism 

9. Predator - an organism that seeks out other organisms for food 

10. Trophic level - each step in a food chain or web 

11. Omnivore - an organism that eats both plants and animals 

12. Food web - a pattern of interconnected food chains 

13. Decomposers - organisms that break down previously living 

organisms and their waste 

14. Biomass - the total weight of all living organisms in each 

trophic level 

15. Biomagnification- the process of contaminants becoming increasingly 

concentrated at each higher trophic level in a food 

chain or web 

Blackline Master 6, Field Form For Food Webs 

Answers will vary depending on geographic location of area, as 

well as type of ecosystem visited. 

Blackline Master 7, The Big Picture 

1. The bear and the heron are at the highest trophic levels. The 

bear could be as high as a fifth trophic level, after it eats a snake, 

which eats a bird, which eats a nymph, which eats phytoplankton. 

The heron could be on the fifth trophic level as well. 

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2. Biomagnification is the process by which contaminants become 

progressively concentrated up the food chain as organisms 

eat contaminated organisms. If phytoplankton absorbed harmful 

contaminants in the water, then the contaminants would be passed 

onto the nymph upon eating the phytoplankton. The bird that 

eats nymphs would also be ingesting harmful contaminants. A 

snake that eats a bird containing the contaminant could pass the 

contaminants on to the bear who eats it. 

3. Decomposers break down dead plants and animals returning 

nutrients and matter to living plants and organisms. For example, 

fungi and bacteria break down dead trees, returning nutrients and 

matter to the soil. In turn, living trees absorb these nutrients 

from the soil. 

4. As you go up the energy pyramid, the amount of energy available 

from organisms in the ecosystem decreases. The pyramid is 

adjacent to the food web, representing the decreasing amount of 

energy available by organisms at different positions on the web. 

For example, a great deal of energy is available in the producers 

phytoplankton and berries. There is less energy available in 

animals that consume the producers, such as in squirrels and 

nymphs. Further up the food web are trout, birds, and snakes. 

These organisms have less energy than the organisms below them. 

At the top of the food web are bears and herons, which contain 

the least amount of energy and are at the top of the energy pyramid. 

The reason that less energy is available in these organisms 

at the top of the pyramid is because a great deal of it is lost in the 

form of heat. 

5. A biomass pyramid is similar to the energy pyramid in that it 

can be placed adjacent to the organisms on the food web, representing 

the decreasing biomass of the organisms further up the 

food web in an ecosystem. The greatest amount of biomass in 

this food web is found in the producers–phytoplankton and berries. 

The next greatest amount of biomass is found in the nymphs 

and squirrels. The next greatest amount of biomass is then found 


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further up the food web in trout, birds, and snakes. The least 

amount of biomass is found in the animals at the top of the food 

web: carnivores such as bears and herons. 

Blackline Master 8, Name That Critter 

1. This organism has powerful teeth and strong jaws to cut down 

large trees. Eats bark and plants. 

Name? Beaver 

Producer or Consumer? Consumer 

Herbivore, Carnivore, or Omnivore? Herbivore 

2. This organism looks and even sounds something like a wolf, 

but is much more common. It visits the pond to look for most 

anything to eat. 

Name? Coyote 


Herbivore, Carnivore, or Omnivore? Omnivore 

3. This organism grows on a prickly vine, and is used to make 

jam. 

Name? Blackberry or raspberry 

Producer or Consumer? Producer 

Herbivore, Carnivore, or Omnivore? A plant manufactures its 

own food, and is, thus, none of these. 

4. This mammal is tough when cornered, has two black eyes, and 

feeds on nearly everything it can catch in the pond. 

Name? Raccoon 



5. This organism has many fins, feeding on insects and plants. 

Name? Fish 


Herbivore, Carnivore, or Omnivore? Herbivore, Carnivore, or 

Omnivore, depending on species. 

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6. This organism lives in the water, has powerful claws, a hard 

outer shell and eats both plants and animals. 

Name? Crayfish 



7. This organism flies in the air, has beautiful wings, and eats 

mostly plants. 

Name? Butterfly 


Herbivore, Carnivore, or Omnivore? Herbivore 

8. This amphibian lives mostly in the water, is a great jumper, 

and catches insects for its food. 

Name? Frog 


Herbivore, Carnivore, or Omnivore? Carnivore 

9. This organism lives in the water, produces its own food from 

the sun, and is often mistaken for seaweed. 

Name? Algae 

Producer or Consumer? Producer 

Herbivore, Carnivore, or Omnivore? A plant manufactures its 

own food, and is, thus, none of these. 

Internet Resources 

1. Visit the U.S. Fish and Wildlife Service's Ecosystem 

Approach to Fish and Wildlife Conservation page at 

http://www.fws.gov/~r9ecosys/eco.html 

This fascinating page divides the United States into seven regions 

of Watershed Based Ecosystem Units. These plans include 

descriptions of the local ecological resources, issues relevant to 

the resources, and goals for local implementation of the ecosystem 

approach. Divide your class into seven groups and assign 

each group a region. Have them recap the information presented 

in the website and analyze the issues that are unique to that region. 

Have them compile other data pertaining of these regions, 

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such as population statistics, climatic and topographical profiles, 

and economic realities. How do these factors effect the ecosystems 

of the regions? How do the ecosystems affect these factors? 

What steps does the region need to take in order to ensure that its 

ecosystems survive in the future? 

2. NASA's Athena Curriculum on Oceans has a website 

titled Ocean Color Viewed From Space at 

http://www.athena.ivv.nasa.gov/curric/oceans/ocolor/ 

index.html 

This page contains information on phytoplankton, the organism 

at the base of the food web. It also contains two science journals 

that students can use as activities to discern the productivity of 

phytoplankton in the oceans, plus a movie of the distribution of 

plant life on Earth from satellite measurements in space. 

3. The Kids! Renew America page at 

http://www.crest.org/sustainable/renew_america/ 

mainkids.html 

contains valuable information for young people regarding their 

participation in ecological programs. A Youth Action Guide and 

Resource Guide provide tips for kids on becoming active in environmental 

concerns. Assign your students a community or global 

service project by asking them to pick one or more organizations 

and become involved. After a month has elapsed, have the 

students report about their involvements to the class. 

4. The Global Classroom at 

http://www.globalclassroom.org/index.html 

contains valuable resources for teachers and kids on a variety of 

subjects. These subjects change frequently, so follow the links. 

An invaluable tool for teachers! 

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Script of Recorded Narration 

(Opening Scenes - different exciting shots of plants and animals 

in Vermont, such as moose, coyotes, deer, beavers, and great blue 

heron) 

Hi, welcome to the White River located in the Green Mountains 

of Vermont. My name is Dr. Brian Jerome and, as you can see, I 

am spending this crisp, cool fall afternoon fly fishing. I’m participating 

in a food web or food chain. 

During the next few minutes, we are going to study the interactions 

of the many plants and animals that live in and along this 

river. And if I am lucky, I may even catch a fish. 

We are going to take a look at food chains, food webs, and the 

types of organisms, including producers and consumers, that make 

them up in ecosystems. 

In other words, we are going to take a look at what eats what in 

the White River ecosystem. 

First, let's take a plane ride to see what this river looks like in the 

air. 

Below is the White River ecosystem. An ecosystem is a place 

where plants and animals interact with the environment. 

This is a river ecosystem or a riparian ecosystem. 

The White River is actually part of the much bigger Connecticut 

River riparian ecosystem, which drains into the Atlantic Ocean. 

The White River is supplied with bountiful amounts of water 

from ample rain and snow. 

The climate is moderate, with warm summers and cold winters. 

The White River is located in mountainous terrain. 


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These factors, along with others, have a great influence on the 

type and interactions of the plants and animals. And there are a 

wide variety of plants and animals. 

Some of the plants include ferns; wildflowers; shrubs, such as 

this colorful sumac; trees, like these birch trees and these colorful 

maples in autumn colors; and conifers, such as these white 

pines; as well as aquatic plants, such as these cattails and lichens, 

such as these growing on this stump. 

In fact, there are over 200 different species or kinds of plants in 

the White River ecosystem. 

There are also many different kinds of animals including: salamanders; 

many different types of ducks, such as these Mergansers; 

insects, such as this wasp; large vertebrates, such as this 

bull moose; and small invertebrates, such as these mussels; whitetailed 

deer; fish, such as this large-mouth bass; reptiles, such as 

this turtle; beavers, capable of making large lodges like this one; 

river otters, once nearly extinct in many areas, and turkeys, just 

to name a few. 

All these plants and animals interact with each other and the environment 

in and along the White River ecosystem. 

I am paddling over thousands of organisms, most of them you 

can't see with the naked eye. In fact, one handful of water contains 

dozens, if not hundreds, of microscopic organisms called 

plankton. 

Plankton are organisms that float in the water. Phytoplankton is 

one type. It is a mixture of microscopic plants. 

Phytoplankton is found in ponds, lakes, and is found throughout 

the world's oceans, as seen in various colors on this satellite image. 

It is a very important food source and is also responsible for producing 

oxygen. Phytoplankton, like other green plants is a producer, 

meaning that it produces or makes its own food. 

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Producers take simple raw materials and convert them into food. 

Converting energy from the sun, along with water and a gas called 

carbon dioxide, plants make a simple sugar called glucose, commonly 

used for medical treatment. 

This process of taking carbon dioxide, water and with the sun 

producing oxygen, water, and sugar is called photosynthesis. 

Without photosynthesis, none of us would be able to survive. 

Most animals, including humans, either directly or indirectly utilize 

the energy that plants bind up in sugar or food they produce. 

Producers are the ultimate source of energy in most ecosystems. 

Organisms that cannot make their own food, such as these cows, 

depend on producers for food and energy. In this case, they are 

eating grass, which is a producer. 

When animals, like these sheep, eat grass, they are called consumers. 

Other types of animals, such as this hawk, consume animals. They 

are also called consumers. 

You may be wondering what I am using for bait. I am using an 

artificial fly that imitates an organism that lives under these rocks 

called the caddisfly nymph. This is the young form of the flying 

caddis insect. It eats microscopic plants. 

It is a special kind of consumer called a herbivore. Herbivores 

are animals that eat plants. 

Here, in the White River, nymphs of a variety of insects are often 

eaten by fish, such as trout. Trout eat other animals; thus, they 

are called carnivores. Consumers that eat other animals are called 

carnivores. In other words, they are meat eaters. 


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Trout are consumers, eating nymphs and other small animals. 

The nymph is called the prey. Animals that seek out other animals 

for prey, such as the trout, are called predators. 

The fishing has slowed down a little bit on the river, and I may 

have discovered one of the reasons why. I have some competition 

here, a heron. 

One of the top predators along the White River is the Great Blue 

Heron. It has long sharp beak, long legs for wading, a huge wingspan 

and keen ability to capture many types of prey including 

rodents, snakes, and fish. 

A heron is a type of consumer or predator that eats animals. 

A food chain illustrates the feeding relationships and transfer of 

energy between organisms in a specific place. The reason it is 

called a food chain is because each organism is linked to the other, 

as in a chain. 

The feeding relationships that we've just discussed form a food 

chain that looks like this, with phytoplankton being eaten by a 

nymph, which is also eaten by a trout, which is then eaten by a 

heron. 

Organisms in a food chain are either producers, or consumers. 

Phytoplankton is a producer, with the other organisms being consumers. 

Each level in a food chain is called a trophic level. Trophic comes 

from the Greek work "trophikos" for nourishment or food. These 

are numbered first, second, third and fourth trophic level. 

As one organism eats another in a food chain, matter is transferred, 

meaning that the matter or mass of an organism is eaten 

by the next organism. 

When we eat something, we are taking in matter and energy. We 

need energy to move and carry out body functions. The food chain 

demonstrates the transfer of energy. 

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But food chains rarely exist in nature as isolated single chains by 

themselves because many animals in an ecosystem, like crows, 

eat more than just one kind of food. 

For example, one such animal left this. It is feces or scat that 

came from a black bear. We can learn a lot about animals by 

looking at their scat. 

If you will look closely, you can see seeds and we know that this 

bear was eating apples. 

Bears eat both–fruits, such as apples and rodents, such as this 

squirrel. They are both herbivores and carnivores. 

Omnivores are animals that eat both plants and animals. 

Picture that these raspberries were eaten by a small bird, which 

in turn was eaten by a snake, which was eventually eaten by this 

Great Blue Heron. 

It might also be possible for the bear to eat the berries, or snakes. 

And suppose that this squirrel could serve as food to a bear or a 

snake, or it could also eat the berries. 

As you can see, our simple food chain quickly becomes a tangled 

web. We call this a food web. A food web is a much more realistic 

representation of what actually occurs in nature, and represents 

many intermeshed food chains. 

Another very important player in food webs are decomposers. 

Decomposers consist of fungi, worms, bacteria, molds, and any 

creature which helps break down dead organisms. They are constantly 

at work, as is this mold on this piece of bread. 

When you walk through the forest, you don't see towering piles 

of dead trees and animals. That is because decomposers break 

them down. 


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These logs in the White River are decomposing at this very moment. 

And household scraps and yard trimmings are being broken down 

in this compost pile. 

Adding decomposers to our food web, we can see that everything 

is eventually broken down by decomposers. 

Decomposers, like these worms, recycle nutrients from dead organisms, 

allowing living ones to flourish. 

We can rearrange this food web with producers at the bottom 

and then consumers further up. 

Not only are helpful things like nutrients passed from organism 

to organism, but so is energy. When one organism eats another 

organism, energy or food, is transferred. When energy is transferred 

from one organism to another, a great deal of it is lost or 

given off in the form of heat. 

In fact, in many cases, nearly 90 percent of the energy is lost in 

the form of heat as is seen along this food chain. 

This concept of energy loss can also be illustrated in a type of 

pyramid called an energy pyramid. An energy pyramid compares 

the energy available at each level of the food chain. 

Notice with each successive feeding level that the amount of energy 

decreases greatly so that as one organism eats another, less 

energy is available at the top of the pyramid. 

By studying food chains and webs, we can also learn about something 

called biomass. 

Biomass is the mass or weight of an organism and its parts, such 

as these leaves. 

For example, this nymph weighs a fraction of a gram. If we were 

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to catch all the nymphs in this stream and other microscopic food 

sources, their biomass would be greater than the biomass of all 

the trout. 

We can view biomass in this biomass pyramid where you can see 

that the total amount of biomass decreases as you go up the pyramid. 

In most healthy ecosystems, the biomass of the producers, or 

plants, is far greater than the biomass of the consumers. 

While energy flows through ecosystems, matter is recycled. 

Water, carbon, oxygen, nitrogen, and other chemicals needed for 

life are recycled continually. 

These materials come from waste materials and dead organisms. 

They are broken down and made useful to living organisms by 

decomposers. For example, these trees are absorbing the nutrients 

from once previously living plants and animals. It is a type 

of natural fertilizer. 

Contaminants, such as pesticides, can also be passed along the 

food chain that can be harmful to animals and humans. 

Biomagnification is the term used to describe the process of contaminants 

being passed along the food chain and becoming concentrated 

in animals higher up the food chain. 

The process of biomagnification was brought to the public's attention 

by Rachel Carson in a book titled Silent Spring in which 

she described how the harmful chemical DDT was passed along 

the food chain and caused the egg shells of eagles and other birds 

to become thin, not allowing young to develop properly. 

This caused certain bird populations, especially hawks, eagles 

and falcons to plummet. But the eventual banning of DDT and 

other harmful pesticides has reduced these toxins in the food web 

and allowed populations of these birds at the top of the food web 

to rebound. 


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Along the White River the food chain was drastically altered by 

early settlers disrupting the flow of the river over 200 years ago. 

Large dams, built for water power to run mills, prevented migrating 

salmon going from the Atlantic Ocean upstream along 

the Connecticut River into the White River. 

Serving as a food source for people, eagles, bears, and many other 

animals, these salmon all but disappeared from these waters. 

Unfortunately I didn't catch this one on my fly rod. It's an Atlantic 

salmon from the Bethel National Fish Hatchery here on the 

White River. 

Today, researchers with the U.S. Fish & Wildlife Service and the 

states along the Connecticut River are attempting to reintroduce 

the salmon by raising them in this hatchery. By helping them 

reproduce, their chance of survival is greatly increased. 

The return of the Atlantic salmon to Vermont is just one of the 

many efforts throughout the world to help food webs return to 

their once natural state. 

This diagram summarizes many of the terms and concepts discussed 

during the past few minutes, showing the feeding relationships 

along the White River between producers and consumers, 

illustrating on the right that energy is lost further up the food 

pyramid or web. And due to decomposers, matter is recycled. 

I finally have a nice trout on the line. I'll reel it in so we can see 

what it looks like. I’s a nice brook trout. 

I will let him go so he can continue to be a part of the food web in 

the river. 

I hope you’ve enjoyed studying the relationships of the many 

plants and animals here along the White River. Next time you 

get a chance, observe the feeding relationships of the plants and 

24 


animals in your neighborhood. You will be amazed at what you 

find. 

Video Quiz 

Students may write their answers on a separate sheet of paper or 

on Blackline Master 1, Video Quiz. 

1. An __________ is a place where plants and animals interact 

with the environment. 

2. Green plants are also called _____ because they make their 

own food. 

3. Animals that cannot produce their own food are called 

____________. 

4. ________ are organisms that eat other animals. 

5. A food chain or food ______ illustrates the feeding relationships 

in a place. 

6. Each level in a food chain is called a _________ level. 

7. When we eat something, we are taking in ________ and energy. 

8. __________________ are important organisms that break 

down dead organisms. 

9. When one organism eats another organism, a great deal of 

energy is lost in the form of ______. 

10. An energy pyramid shows that _____ energy is available at 

each step up the pyramid. 


25

1 

Directions: Fill in the blank with the correct answer. 

FOOD CHAINS AND WEBS 

Video Quiz 

1. An ________________ is a place where plants and animals interact with the environment. 

2. Green plants are also called ________________ because they make their own food. 

3. Animals that cannot produce their own food are called ________________. 

4. ________________ are organisms that eat other animals. 

5. A food chain or food________________ illustrates the feeding relationships in a place. 

6. Each level in a food chain is called a ________________ level. 

7. When we eat something, we are taking in ________________ and energy. 

8. ________________ are important organisms that break down dead organisms. 

Name __________________ 

Date ___________________ 

9. When one organism eats another organism, a great deal of energy is lost in the form of ________________. 

10. An energy pyramid shows that ________________ energy is available at each step up the pyramid. 

©1998 Brian Jerome, Ph.D. Published and Distributed by AGC/United Learning 

1560 Sherman Av., Suite 100 Evanston, IL 60201 

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2 


Chaining It Together 

Name __________________ 

Date ___________________ 

1. Using your knowledge of food chains and the following organisms, in the space below, create a diagram 

of a food chain containing the organisms listed below. Use arrows to show that organisms are eaten 

by other organisms further along the chain. Also,make a box above each organism, and using color 

pencils create a drawing of the organism. Leave plenty of room to add other things requested further 

down the page. 

Phytoplankton 

Nymph 

Trout 

Heron 

2. After creating your basic food chain, label each organism either a producer or consumer. 

3. Last, label each step along the food chain with the following labels: first tropic level, second trophic 

level, third trophic level, and fourth trophic level. 



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3 


Web Weaving 

Name __________________ 

Date ___________________ 

1. In the space below, using your knowledge of food webs and the organisms listed below, create a food 

web. Use arrows to show that organisms are eaten by other organisms further along the chain. Also 

make a box above each organism, and using color pencils create a drawing of the organism. Leave 

plenty of room to add other things requested further down the page. 

Phytoplankton Trout 

Berries Heron 

Squirrel Snake 

Nymph Bird 

Bear 

2. Add decomposers to your food web and include arrows where appropriate. 

3. Describe how this food web may be similar or very different from food webs in your region. 



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4 


Word Search 

Name __________________ 

Date ___________________ 

Directions: Find the hidden vocabulary words listed below. Words may appear vertically, horizontally, 

or diagonally. 

Food chain Ecosystem Riparian Producer Consumer 

Herbivore Carnivore Prey Predator Trophic level 

Omnivore Food web Decomposers Biomass Biomagnification 

A F B G B I O M A G N I F I C A T I O N C H D I L 

J V K W L X M Y N Z O A P B Q C R D S E T F U G T 

H O I F O O D C H A I N S J P K Q C L R M S N T R 

U G V H W I X J Y K Z L A M B N C A O D P E Q F O 

D R S R Y E T Z U H H E R B I V O R E A R W B X P 

E C M I D N C E O F P G Q H R I S N J T K U L V H 

C W D P X P R O D U C E R E Y F Z I G A H B I C I 

O J S A K T L U S M V N W O X P Y V Z R E I R A C 

M B L R C M D N E Y O F D G Q H R O I S J O T K L 

P U D I V E W F X G S Y H Z I A J R B K T M C L E 

O M V A N W O X B D Y T Q U Z A E E T A B N U A V 

S C O N S U M E R V C W E D X E Y F D A G I B B E 

E C L D M E W N F O G H Q M I R J E S K T V T U L 

R H R I S D J T K U V L W M X N R Y O Z P O A Q B 

S C L D O M E N F P R E Y G O P H P I Q J R D K Y 

T F U O V G W I X H Y I Z J A K B L C M D E E O X 

P O F Q Y R Z S A B I O M A S S T B U C V D D W E 



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5 


Vocabulary Words and Definitions 

Directions: In the spaces provided, write definitions of the following vocabulary words. 

1. Food chain- 

2. Ecosystem- 

3. Riparian- 

4. Producer- 

5. Consumer- 

6. Herbivore- 

7. Carnivore- 

8. Prey- 

9. Predator- 

10. Trophic level- 

11. Omnivore- 

12. Food web- 

13. Decomposers- 

14. Biomass- 

15. Biomagnification- 

Name __________________ 

Date ___________________ 

- 



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Field Form For Food Webs 

Name __________________ 

Date ___________________ 

Directions: Use the following form to list the organisms in the vicinity of your school or your home. List 

the organisms you observe, and decide if they are consumers or producers. Also list how the organisms 

get their energy, and what organisms (if any) eat them. Once you have filled in the chart, then create a 

food web based on the data you have gathered. 

Organism Consumer or Producer Derives Energy From Serves as Food For 

Food Web Diagram: 



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7 


The Big Picture 

Name __________________ 

Date ___________________ 

Directions: The following complex diagram summarizes many important concepts relating to food webs, 

cycling of matter, and flow of energy in ecosystems. Take a few minutes to study the diagram, then answer 

the following questions. 

1. What animal(s) on the food web above are on the highest trophic level? What trophic level is it? 

2. Define in your own words the term biomagnification. Suppose that in the food web above, phytoplankton 

absorbed harmful chemicals in the water. Describe how these chemicals could end up in the body of a bear. 

3. Describe the role of decomposers in the food web. Describe where the matter they break down goes. 

4. Study the pyramid on the right. Describe what happens to the amount of energy as you go up the pyramid. 

Notice that the pyramid is placed adjacent to the food web. Describe the energy value of the animals at different 

points in the food web in terms of the energy pyramid. 

5. Describe how a biomass pyramid would be positioned on the diagram. What would be the relative amount 

of the biomass of the organisms on the food web compared to other organisms? 



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Name That Critter 

Name __________________ 

Date ___________________ 

Directions: The following clues describe organisms that live in and around a pond ecosystem. Write the 

name of the animal and decide if it is a producer or consumer. If it is consumer, state if it is a herbivore, 

carnivore, or omnivore. Use these organisms to create a food web diagram on the back of this sheet. 

HERBIVORE, 

PRODUCER OR CARNIVORE, 

CLUE ORGANISM CONSUMER OR OMNIVORE 

This organism has powerful teeth 

and strong jaws to cut down large 

trees. Eats bark and plants. 

This organism looks and even 

sounds something like a wolf, but is 

much more common. It visits 

the pond to look for most anything 

to eat. 

This organism grows on a prickly 

vine, and is used to make jam. 

This mammal is tough when 

cornered, has two black eyes and 

feeds on nearly everything it can 

catch in the pond. 

This organism has many fins, 

feeding on insects and plants. 

This organism lives in the water, 

has powerful claws, has a hard 

outer shell, and eats both plants 

and animals. 

This organism flies in the air, has 

beautiful wings, and eats 

mostly plants. 

This amphibian lives mostly in the 

water, is a great jumper, 

and catches insects for its food. 

This organism lives in the water, 

produces its own food from the sun, 

and is often mistaken for seaweed. 



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Food Chains and Webs

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