Food Webs Lesson
lesson introduction
Welcome to the "Feeding Relationships and Food Webs in the Great Southern Reef" lesson. This engaging and interactive lesson provides an invaluable opportunity for your Year 7 science students to dive deep into the unique and complex ecosystems that thrive in Australia's Great Southern Reef.
By exploring the feeding relationships between organisms, your students will learn the fundamental concepts of trophic levels, food chains, and food webs while developing a strong understanding of how energy flows through an ecosystem. This lesson is designed to spark curiosity and foster critical thinking as students research, draft, and ultimately create their own food webs based on real species from the Great Southern Reef.
tEACHING SEQUENCE
Introduction. Begin the lesson by introducing the concept of food chains and food webs. Use the Presentation Slides to explain key terms such as trophic levels, primary producers, consumers, and detritivores. Students will also have access to these slides through the online course. Discuss Learning Intentions and success criteria outlined at the bottom of these notes. Explain how students will demonstrate their understanding through their research, diagrams, and the creation of accurate and detailed food webs.
Research stage. Students will research the diets and trophic levels of various species from the Great Southern Reef using the Marine Life section of the GSR website, filling out the Student worksheet. Encourage students to start by examining the 'fast facts' section for each species and identifying where they fit within the ecosystem. Circulate the room to answer questions, provide support, and ensure students are correctly identifying the trophic levels of their chosen species.
Drafting the food web. Have students plan how they will lay out their food web. Discuss the importance of starting with primary producers at the base and connecting organisms with arrows that indicate the direction of energy flow. Allow students to choose whether to draft their food web digitally or on paper. Encourage students to discuss their drafts with a partner or small group, receiving feedback on the accuracy and clarity of their food webs.
Final Copy. Students should now create their final version, incorporating any feedback from the drafting phase. Emphasise the importance of making their food web visually appealing, with clear arrows and possibly using colours to differentiate between trophic levels.
Extension. Pose the extension questions to the class, such as what would happen if a key predator like sharks were removed from the ecosystem. Allow students to hypothesise the impacts on their food webs and the broader ecosystem.
Wrap up. Briefly review the main ideas covered in the lesson, including the roles of different organisms in the food web and the importance of energy flow. sk students to reflect on what they learned and how it relates to the real world. Encourage them to consider how human actions can impact these delicate ecosystems.
discussion ponts
Energy Loss: Discuss with students the concept of energy loss at each trophic level and why there are generally fewer organisms at the top of a food web.
Human Impact: Explore how overfishing or pollution might alter the Great Southern Reef's food web. Engage students in a debate about the pros and cons of human intervention in marine ecosystems.
assessment ideas
Formative: During the research phase, check students' understanding by asking probing questions about their chosen species and their place in the food web.
Summative: Evaluate the final food webs for accuracy, correct use of arrows to indicate energy flow, and proper organisation of trophic levels. Consider the clarity and creativity of the presentation as well.
DIFFERENTIATION
For Advanced Learners: Encourage students to explore the impact of environmental changes (e.g., climate change or pollution) on their food web. Ask them to predict how these changes might alter species interactions and energy flow.
For Struggling Students: For a faster lesson or lower level students use worksheet page 1 only and consider pre fill out some of the trophic levels. Provide pre-structured templates with some organisms already placed in the food web. Allow them to focus on connecting the dots with arrows and filling in the gaps.
misconceptions
Students might think that all species in a food web are equally important. Clarify that the removal of keystone species (like sharks) can have a disproportionately large impact on the ecosystem.
There may be confusion about the direction of arrows in a food chain. Emphasise that arrows represent the flow of energy and should point from the prey to the predator.
learning intentions
Students will understand:
Trophic levels represent the position that an organism occupies in a food chain
Primary producers use photosynthesis to get energy from the sun
Energy from primary producers are passed on to other organisms
Food chains represent one pathway of flow of energy through predation
food webs represent interactions between food chains.
success criteria
Students can:
Demonstrate feeding relationships in diagrams
Collect information about marine species from an Australian kelp forest ecosystem
Use research to show feeding relationships in a food chain and food web, using arrows to show the transfer of biomass from one trophic level to another.
year 7 science curriculum links
(ACSSU112) Interactions between organisms, including the effects of human activities can be represented by food chains and food webs
(ACSSU111) Classification helps organise the diverse group of organisms
(Sustainability OI.2) All life forms, including human life, are connected through ecosystems on which they depend for their wellbeing and survival.
cross curricular links
Geography: Discuss how the physical environment of the Great Southern Reef supports the organisms within it. Students could look at how geographical features such as ocean currents, temperature, and seabed composition influence species distribution.
English: Have students write a short report or a creative story about their food web, explaining the relationships and why each species is crucial to the ecosystem’s balance.
