1. Lesson Title: Silt impact on Habitat
Class: KS2 Topic: Conservation Time Allocation: 30-45mins
Learning Intentions
Identify the environment needed to support
good-quality spawning grounds for salmon.
Identify land-use practices or events that
prevent salmon eggs from incubating and
hatching.
Success Criteria
Identify factors requited to support
good quality spawning grounds for
salmon
Key Vocabulary
Conservation
Silt
Oxygen
Pollution
Introduction
Divide the class into groups of mixed ability
Resources
two clear pint containers (such as canning
jars)
marbles
ruler
water
one cup of sand
24 salmon eggs (from a fish-bait store)
Development (Activity)
Each group fills their two empty jars half full with the marbles.
Pour enough water into each jar to just cover the marbles (without filling the jar).
Put at least 12 salmon eggs in each jar. Observe and discuss what you see.
Swirl the eggs (to simulate water flowing over them which keeps them cool and brings
them oxygen).
Discuss what might happen if silt was suddenly added to the stream.
Each group will now add one cup of sand into one jar to simulate the silt. Shake the jar
gently twice and let the sand settle.
Allow each group time to discuss its observations and what the addition of silt means to
salmon eggs.
Key Questions
Throughout the experiment ask pupils to
comment and question what they see and offer
explanation as to why it may be happening

2. Plenary
Ask each group to present its conclusions to the rest of the class. Record all conclusions in a grid on the
interactive whiteboard.
Engage the entire class in a discussion of the results and what kind of conditions were simulated.
Differentiation
Groups should be of mixed ability and additional
support should be provided where required.
Extension
Allow pupils to design their own experiments
Other Notes