Food Chains by the River

Overview

In this fourth lesson of the Collie River Animal Guardians unit, students investigate how organisms depend on one another for food. They identify producers, consumers and decomposers, then construct and explain simple food chains using Collie River habitat examples. This builds on prior learning about local habitats and prepares students to consider how changes to one species can affect others.

Learning intentions

• WALT identify producers, consumers and decomposers in a river habitat.
• WALT construct a simple food chain using Collie River organisms.
• WALT explain that arrows show the direction of energy flow from food to eater.
• WALT communicate a scientific explanation using appropriate vocabulary.

Success criteria

• I can identify a producer and consumers.
• I can place organisms in a logical food chain.
• I can explain what the arrows show.
• I can use the words producer, consumer, decomposer and energy correctly.

Curriculum links

• Science: roles and interactions of consumers, producers and decomposers in a habitat, and food chains as feeding relationships.
• Science: creating texts to communicate findings and ideas using scientific vocabulary and digital tools where appropriate.
• Science: using a scaffold to plan, conduct and discuss an investigation or simulation safely.
• HASS: the importance of environments, including vegetation and water sources, to people and animals in Australia.

Lesson structure (60 minutes)

1. 0–7 min · River habitat hook. Teacher displays a photograph or illustration of the Collie River and asks, “Where does the energy for every animal in this picture begin?” using the river habitat hook slide. Students silently observe, share an initial idea with a partner and contribute examples of living things they might find near the river.

2. 7–17 min · Teach the roles. Teacher uses the producer, consumer and decomposer slides to introduce producers as organisms that make their own food, consumers as organisms that eat plants or animals, and decomposers as organisms such as fungi and bacteria that break down dead material. Students sort orally presented examples into the three roles, using colour-coded hand signals or role cards, and rehearse: “A ___ is a ___ because ___.”

3. 17–25 min · Model energy flow. Teacher models a simple chain such as river plants or algae → insect larva → frog or fish, placing arrows between organisms and clarifying that an arrow means “energy flows to”. Teacher also explains that the Sun is the original energy source, while the organism at the beginning of the chain is the producer. Students use movement to act out the chain, facing and pointing towards the organism that receives energy.

4. 25–42 min · Team card sequencing. Teacher places students in five groups of four and distributes the Food Chains Sorting Cards alongside selected river-habitat picture cards or teacher-prepared labels. Groups identify the producer, arrange a logical chain and add a decomposer beside the chain to show what happens when organisms die; the teacher circulates, asking, “What does this organism eat?” and “Which way should the arrow point?” Students physically sequence the cards, draw or place arrows, and practise explaining their chain to another group.

5. 42–53 min · Record and explain. Teacher distributes the Collie River food-chain recording sheet and displays the recording and explanation prompt slide. Students independently record one chain, label each organism as producer or consumer, add a decomposer, draw arrows and complete the sentence: “Energy flows from ___ to ___ because ___ eats ___.” Students who need support may use their group’s cards and dictate their explanation to a partner or adult.

6. 53–60 min · Plenary and exit check. Teacher displays the plenary challenge slide and asks students to hold up one finger for producer, two for consumer or three for decomposer as several organisms are named. Students complete an oral or written exit response: “In the chain ___ → ___ → ___, the arrows show ___.” Invite two students to explain why reversing an arrow changes the meaning.

Resources

• the Collie River food-chain slide deck
• the Collie River food-chain recording sheet
• the Food Chains Sorting Cards
• Collie River habitat photograph or local habitat image
• Teacher-prepared picture or word cards for river plants/algae, insects, frogs, fish, birds and decomposers
• Blu-tack or magnetic strips for displaying cards
• Coloured pencils and thick markers
• Five group work areas or floor spaces

Assessment

• Listen for accurate use of producer, consumer, decomposer and energy during questioning, role sorting and partner explanations.
• Observe group chains for logical feeding relationships and correctly directed arrows; photograph or note misconceptions for the next lesson.
• Use the worksheet and exit response to assess whether each student can identify roles, construct a chain and explain arrow direction.

Differentiation

• Support learners with large icon-supported cards, colour-coded role borders, partially completed chains, a visual arrow showing “energy flows to”, and repeated oral rehearsal before writing.
• Provide dyslexia-friendly access through a clear sans-serif font, generous spacing, minimal written instructions, read-aloud slides and worksheet instructions, paired reading and permission to respond orally or by drawing.
• Use mixed-ability groups of four with defined roles: card manager, reader, arrow checker and speaker. Accept labelled drawings, oral recordings or dictated responses where writing is a barrier.
• Extend advanced learners by asking them to join two chains into a food web and predict what could happen if one species disappeared, including which organisms might increase or decrease and why.