Meet the Waterbugs (Foundation to Year 2)

Meet the waterbugs (Foundation to Year 2)

Lesson plan

Introduction

Macroinvertebrates (waterbugs) tell us a lot about water quality through their known sensitivities and tolerances to pollution and disturbance. The types of gills they have, the food they eat and the place they live all contribute to their survival. Scientists observe the animals to learn about where they live, their anatomy and what they need to survive.

This lesson plan focuses on developing an understanding of waterbugs and how they live. There is a strong focus on working scientifically as students make observations and identify the key features and characteristics of waterbugs.

Activity 1: What are waterbugs?

Students explore the features of waterbugs and where they live.

Activity 2: Hunting waterbugs?

Students investigate the features and behaviour of waterbugs found in a local waterway.

Activity 3: How do waterbugs live?

Students discuss what they found out about the waterbugs and explore how waterbugs live.

Equipment

An image of local waterway

A sampling net, bucket

Images of waterbugs or stuffed-toy waterbugs (optional)

Activity 1: What are waterbugs?

Students identify the features of waterbugs and where they can be found.

Duration

15 minutes

Activity steps

1. Display an image of a local waterway. Ask students if they can tell if the waterway is healthy for the plants and animals that live in it or not. Explain that one of the ways that we can tell if a river or creek is healthy is to find out what is living in the water.

1. Explain that you have been to a waterway this morning to see what is living there and show students the equipment that you used. Use props such as net, bucket, etc.
2. Explain that you put some water into a bucket (mime scooping) and used a net to scoop through the water. By sweeping the net through the water and through the mud at the bottom, say that you were able to catch some of the animals that live there in your net. Then, you emptied all the things from your net into a bucket.

Ask: Do you think I can catch an eel and a platypus in my net? (No!)

1. Explain that you could catch really small things in the water called waterbugs. Explain that another name for waterbugs is aquatic macroinvertebrates—aquatic meaning it lives in water, macro meaning big enough to see with our own (naked) eye and invertebrate means they don’t have a backbone like we do.
2. Tell students that our waterbugs can tell us how healthy our creek or river is. In a healthy waterway, we are firstly looking for lots of waterbugs, and then lots of different types of waterbugs.
3. Explain that today students will meet the waterbugs you caught in your net this morning and using their observation skills (just like scientists do) students will look for different features of our waterbugs.
4. Display the image of a local waterway again and ask:

a) In what part of a river do you think we might find these waterbugs?

• Some live on the edges
• Some live in the mud at the bottom
• Some live in the plants etc.

b) What features of the river would help our waterbugs live here?

• Where they can find food and/or air
• Where there isn’t a fast flow of water, where they can cling to rocks etc.
• Clean water
• Avoiding being eaten by hiding/camouflage etc.

1. Explain that our waterbugs have different features that can help them survive in different parts in the river. Explain they are very small and we need to look very carefully with our eyes to see their different features.
2. Show students some images of waterbugs or the stuffed-toy waterbugs. Discuss each waterbug image or soft-toy as you show it:

• What features can you see?
• What colour is the animal?
• How many legs does it have?
• Demonstrate how it swims (moves), etc.

1. Explain that the students are practising their observation skills by looking and discussing the waterbug’s features such as shape, colour, number of legs, etc. Explain that observation is a skill that scientists use as part of their work and today they will put their observations skills to the test!

Activity 2: Hunting waterbugs

In this activity, students investigate real waterbugs and observe their different features.

Duration

15 minutes

Equipment

Digital microscope and plastic petri dishes (if possible)

Waterbug sample in a bucket

For each group:

Plastic spoons

Ice cube trays (white)

Magnifying glasses

Macroinvertebrate ID charts (attached)

Preparation

On the morning of the lesson, use a sampling net to collect waterbugs from your local waterway. Ensure that you collect the samples after the session and return them to the same place.

Activity steps

1. Review what students learned about waterbugs in Activity 1. Explain that in this activity, they are going to hunt for some real waterbugs. Once they have found some, they should use their observation skills to look for different features of their bugs like colours, legs, how they move, etc.

Show them the trays with samples and equipment. Explain the equipment:

• spoons for carefully lifting the waterbugs from the sample
• ice cube trays to spoon water and bugs into for observation
• magnifying glasses to look for features on our bugs
• identification charts (with photos) to help identify common waterbugs

1. Explain how to use the equipment:

• our waterbugs are live animals and we need to treat them carefully
• sorting for bugs requires great observation skills; look carefully for the bugs before scooping them out of the sample. Stirring up the sample makes it harder to see bugs!

1. Divide students into groups. Assist the students for around ten minutes to find, identify and observe the different features of macroinvertebrates in the samples, such as:

• number of legs (e. g. waterbugs with six legs are insects)
• colour
• movement
• shape
• size

Students in Year 2 may be able to spend longer on this activity and they may also like to draw their waterbugs or make notes.

Activity 3: How do waterbugs live?

In this activity, students share what they found out about the waterbugs and explore how waterbugs live.

Duration

15 minutes

Equipment

Some larger waterbugs from the sample in glass jars with lids

Activity steps

1. As a class, ask students to describe the features of waterbugs that were found in the sample:

• size (tiny, small etc.)
• movement (slow, fast)
• shape (spiky, round etc.)
• number of legs

1. Identify a few common waterbugs using observed features (samples in jars can be used to assist with this, if using), for example:

• freshwater snails—slow moving, have a shell, small
• caddisflies—live inside a case, have long legs protruding from its case
• damselflies—six legs, three tails, move quickly
• freshwater shrimp—move quickly, have a lot of legs, are transparent, large in size
• backswimmers—strong swimming legs
• dragonflies—large eyes.

A digital microscopy can be used for this.

1. Ask students to mime some of the waterbugs and act out how they move or ‘dance’ as you discuss each one.
2. Use the identification activity to gather students’ ideas about how these waterbug features might be useful for movement, finding food, to avoid being eaten etc. Refer to ‘A beginners guide to waterbug identification’ (see Resources) for help with this. Questions could include:

• What do you think these features do?
• Why is this a useful feature?

For Year 2 classes:

• How do these features help them to survive?

1. Ask students to think about how they and the community can also help our waterbugs to survive in rivers and creeks such as keeping litter out of waterways, picking up after your dog, replanting trees, etc.
2. Conclude by emphasising the key messages about waterbugs in our waterways:

• Our waterways are home for a range of animals including waterbugs.
• Waterbugs are an important food source for platypus, fish and frogs, they are very sensitive to changes in the environment and are a good indicator of waterway health.
• Everyone can help improve our local rivers and creeks by reducing stormwater pollution and litter—simple things like picking up after your dog, binning rubbish and fixing oil leaks in your car can reduce the impacts.

Resources

A beginner’s guide to waterbug identification, Melbourne Water <

Waterbug Census, Melbourne Water <

[1] Victorian Curriculum and Assessment Authority (VCAA) <http://victoriancurriculum.vcaa.vic.edu.au/> Accessed 14 August 2016.