Download Key Question 10 - Northumberland National Park

r i ve r habit at pack
KEY QUESTION 10
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‘ Who eats what in the river habitat?’
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Objectives
This activity should help pupils to define, in simple terms, what is meant by a food
chain. They should understand that most food chains start with a green plant that
provides food for other living things (a producer of food). Animals that eat these
plants are called herbivores and animals that eat the plant-eating animals are called
carnivores. Pupils should be able to use this information to construct simple food
chains from the river habitat.
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Resources
Per class:
10a wall display - 3 components of a woodland food chain
10b wall display - 3 components of a river food chain
10c wall display - food chain labels (photocopied and cut out from master sheet)
10d wall display - labelled arrows
• Blu-tac
Per pupil:
10e pupil worksheet “River Tweed food chains” (photocopied from master sheet)
• scissors
• coloured pencils
• card
• glue
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Suggested Activities
1. Explain that a food chain, in its simplest terms, shows us who eats what in a river habitat.
2. Hand out the laminated sheets (10a) showing three components of a woodland food chain to
three pupils and ask them to stand at the front of the class holding the cards. (It is easier to start
with a woodland food chain as these creatures will be more familiar to the pupils). Ask the rest of
the class to line them up in order from left to right so that they form a food chain.
3. Introduce the pupils to the terms ‘producer of food’ (plants), ‘herbivore’ (eats plants) and
‘carnivore’ (eats plant eaters) referring to the woodland food chain. Display the woodland food
chain on the wall using two of the laminated arrows (10d) and one set of labels (10c).
4. Now repeat steps 2 and 3 using the laminated sheets (10b) showing three components of a river
food chain.
5. Give each pupil a copy of pupil worksheet 10e “River Tweed food chains”. Explain to them that
they are going to make some river food chains. The worksheet is divided into 3 horizontal
sections. Each section contains one food chain (a producer, a herbivore and a carnivore) from the
river habitat. The pupils have to decide which is which and write the correct label in the bottom
of the boxes (the stonefly nymph is a carnivore). They can then colour in the pictures, cut out the
boxes and stick them on to card in the correct order with arrows between them as in the
examples above.
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6. Once the food chains are complete, use them as a visual aid to discussion. E.g. ask the pupils
what would happen in the first food chain if there were suddenly no freshwater shrimp. What
would happen in the second food chain if there were suddenly no stonefly nymphs? What would
happen if there were no fallen leaves in the third food chain?
Pupils should be able to see that any change in one part of the food chain upsets the balance of
the whole chain. They should also be able to see that most food chains start with plants which
have obtained their energy from the sun. Without plants to convert the sun’s energy into food,
nothing else further up the food chain would be able to survive.
10a
10b
10c
plant
(producer of food)
herbivore
(eats plants)
carnivore
(eats plant eaters)
10d
10e
River Tweed food chains
trout
fallen leaves
freshwater
shrimp
mayfly nymph
stonefly nymph
algae
stonefly nymph
freshwater
shrimp
fallen leaves