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Wetlands and food webs

Target audience: Years 4 and up

What is a 'wetland' exactly, and why are they so important? What are the many living things that depend on them (and each other) to survive? In this resource, the complex food-webs of wetlands are explored through a case study of the Macquarie Marshes in northern New South Wales – a designated Ramsar site. Activities, extensions tasks, and a mobile app are all provided to make this resource engaging and effective for a primary school audience.

Jump to:


By the end of this resource, students will:

  • Understand that living things are interconnected and form food webs and provide habitats for other species.
  • Understand the roles of producers, consumers and decomposers in life cycles.
  • Learn about natural plants and animals of a wetland environment.
  • Appreciate the effects of introduced plants and animals.
  • Understand that relationship between macroinvertebrates and water quality.
  • Build sustainability knowledge.

Curriculum focus

  • ACSSU072 Living things have life cycles.
  • ACSSU073 Living things depend on each other and the environment to survive.
  • ACHASS088 The importance of environments, including natural vegetation, to animals and people.
  • ACHASS090 The use and management of natural resources and waste, and the different views on how to do this sustainably.
  • ACSHE062 Science knowledge helps people to understand the effect of their actions.
  • Key inquiry questions: How does the environment support the lives of people and other living things? How can people use the environment more sustainably? Why are wetlands important?

How to use this resource

This resource can be used as:

  • a stand-alone lesson idea
  • a prelude to the Alien Invaders resource, which expands on how food webs and ecosystems are disrupted by invasive species
  • a collection of related activities on a wetlands theme.

To prepare:

  • Read through this webpage for the complete package.
  • See the tiles for each activity/experiment (images you can click on).
  • Download the resources from the list below of each activity.
Items Required resources Quantity
What is a wetland?    
What lives in a wetland?

Wetlands and food webs worksheet

Waterbirds and macroinvertebrates poster

1 per student, print

1 per 4 students, order or print

Food webs Food web cards 1 pack per class, print
Wetland case study

Wetlands and food webs worksheet

Macquarie Marshes poster

1 per 4 students, order or print
Why are wetlands so important?

Nutrient cycle image

River flows poster

Download to project

Download to project


Biofiltration – Make a filter worksheet

Constructed rain garden image

1 per student, print

Download to project

Engaging with the topic


What is a wetland?

A wetland is exactly that: a naturally-saturated area of land – either all the time, or under water regularly. It's usually near a river – water gets into a wetland when a river is full and spills over into the wetland, or sometimes there's underground water that comes to the surface. Wetlands are also usually where water is slow-moving.

The plants and animals who naturally live there depend on very wet conditions. Although some can go a fair while without flooding, at some point in their life-cycle they will need lots of water to grow their food sources, improve the health of their habitat, provide materials for nesting and/or act as triggers to reproduce.

More information:


What lives in a wetland?

Activity 1: What is naturally found in a wetland?

Worksheet: Questions 1 and 2: Wetlands and food webs worksheet

  1. Students first predict what plants and animals they think might live in or near a wetland (Question 1)
  2. Review the food web (Question 2)


Activity 2: Investigation

Information source: Murray–Darling Basin Authority's (MDBA) waterbird/macroinvertebrate poster (double-sided)

Teacher notes: Pass out a waterbird/macroinvertebrate poster to each table group (or project/view on devices)

Students first view the waterbird side.

Discuss: 'Waterbirds' are birds that rely on water to complete their lifecycle.

Waterbirds need water to:

  • Feed – waterbirds rely on food that grows and lives in wetlands, like insects and plants that live in water.
  • Grow – waterbirds need food and shelter provided by wetlands to grow strong and healthy; some waterbirds migrate across the globe which requires a lot of energy.
  • Breed – healthy wetlands attract waterbirds in great numbers – this allows waterbirds to find a mate and breed.
  • Nest – waterbirds need healthy wetlands so they have the right materials to build nests; some waterbirds build floating nests, so they need the right amount of water to float their nests.

Water at the right time is important to provide waterbirds have what they need.

Explain: The large plants and animals that we see in wetlands are only 1 part of the wetland story. As well as the frogs, fish, plants and birds there are LOTS and LOTS of tiny water bugs called macroinvertebrates in wetlands.

Students then turn the poster over.

Explain: The plants that live in wetlands, and the logs and rocks and so forth, provide great places for lots of macroinvertebrates to live. Macroinvertebrates are food for fish and waterbirds. They are also great places for fish to lay their eggs, and baby fish (and small shellfish) can hide from creatures that eat them. Frogs and turtles also love this environment. Trees that like to 'have their feet wet', like river red gums, also live around wetlands. Their roots provide more homes.

Activity: Students answer questions 3 and 4 on the 'Wetlands and food web worksheet'.


Food webs

Explain: within this web there are 3 different roles in the environment:

  • Producers: these are the guys that make food from the energy of the sun, they don't eat anything else. Can you think of a producer? (plants, trees, grass, crops)
  • Consumers: a consumer eats something to get energy. Can you think of a consumer? (Human, birds, fish, cow, pigs, frogs, turtles…….even horses, sheep, etc.)
  • Decomposers: these are super important in the environment, decomposers have the job of eating all the other things that have died! When they do this they actually turn the dead stuff into fertiliser that is used by producers to stay healthy. Can you think of a decomposer? (This may need prompting….fungi, bacteria, worms, small insects, some fish, mini beasts)



Case study: Macquarie Marshes

Students investigate a special wetland: the Macquarie Marshes of north-eastern New South Wales. The environment of the Macquarie Marshes is a great example of a food web.


Watch the video and research the poster.
Information source: Macquarie Marshes poster


Questions 6 to 9: Wetlands and food webs worksheet
Teacher notes: Divide the class into groups of 4 or 5 and have them investigate the poster. Some students may need support to understand the content. (Students may also need a dictionary, or dictionary app.)

Show the video of the Macquarie Marshes. Note: the regional centre Coonamble, a town of 2,750 people, is near the marshes. The marshes are a similar size.

Show the Macquarie Marshes poster and explain that several rare species breed there, and it is an important spiritual and cultural site for the area's First Nations people, and a tourism destination.

Assign a topic to each group:

Geography of Macquarie Marshes – size, location etc

History (including First Nations)

Animals and plants

Challenges and threats

How to look after wetlands

Students use the poster to learn about the Macquarie Marshes:

  • Each table comes up with 3 interesting facts related to their topic to share with the class.
  • They complete the next 4 questions on their workbook.


Some students may need assistance to count up the total number of species living within the marshes (listed on the poster). Answer: 684.

Then, as a class group, discuss the sorts of things the animals and plants in the marshes might need to be healthy.


Why are wetlands so important?

Apart from providing homes for water-loving plants and animals, wetlands play a role in keeping rivers and soil healthy.

Wetlands do the following important things:


  • Filter water.
  • Keep riverbanks stable so they don't collapse and protect against floods (i.e. reduce soil erosion and increase soil stability).
  • Store water.


All these functions are important for plants, animals, people and the river system we rely on for our drinking water.

Filtering water

Algae, animal droppings, sewage, fertilizer and rotting dead plants and animals make nutrients (chemicals like phosphorus and nitrogen). Some nutrients in water are important as food for tiny animals and plants that are themselves food for other things. But too much is a bad thing and can cause water pollution that's harmful to fish, waterbirds and people.

Nutrient cycle

Wetlands can help – they act like sponges. When lots of water flows across land or over river banks after rain, it may have fertiliser or manure in it. Wetlands soak up the water, dirt and nutrients. Some chemicals sink into the mud. Some of the fertiliser can get sucked up by wetland plants. Bacteria in wetlands 'eat' some of the chemicals from fertilisers. This process is called 'biofiltration'.

Biofiltration is important for all water and in many towns and on farm people have been building or restoring wetlands to ensure biofiltration happens.

Protecting against floods

Wetlands slow water down. They act like a sponge and barrier soaking up water and slowing it down. (View the 'River flows: connecting Floodplains and Wetlands poster' or use the river flows diagram if you need a close up.)

How do wetlands slow water down?

  • They soak up water as it flows through them, like a sponge. This slows the flow of water and reduces the amount of water passing over the wetland.
  • Vegetation, or plants, act as obstacles to slow water down – including dead plants in waterways (called snags) – as water passes or hits obstacles it slows down, just as you would if you ran into a tree.
  • Wetlands are often flat and sometimes shallower and higher than the main river channel. This means wetlands catch water as it spills over from the river, and the water seeps across the landscape slowly. (Rather than flowing fast down the main river channel, the river flow diagram shows this.)

As water slows down dirt and nutrients have a chance to sink to the bottom of the wetland, instead of being carried away. This prevents soil erosion and allows the water to be filtered – because the dirt and nutrients are collected.

During floods, wetlands can protect surrounding areas from floodwaters and fast moving water. This is important for people, plants and animals living in or near rivers.

Towns and farms can be protected from flood waters by having healthy functioning wetlands to soak up floodwaters.

Aquatic animals (i.e. animals that live in water like fish and yabbies) can find hide from fast moving water in wetlands, and in snags where the water is moving slower. The slow moving water gives them a chance to feed and rest.




Students combine everything they have learned by writing or drawing a reflection about what wetlands do for people, plants and animals and how all the animals are connected (e.g. draw a food web or nutrient cycle including their favourite wetlands species).

Activity: Summing up

Time: 10 minutes

Students reflect on what they've learnt by answering worksheet question 9.

Further activity inspiration

This lesson is built on in the resource 'alien invasion' lesson package where you can find more activities linked to wetlands.

Further resources are outlined in the table below.



Information sources

Teacher notes


Read to the class – a book about a visiting migratory shorebird to the Coorong (a critical wetland).

Rusty Loses his Loop by Josie and Matthew Wright-Simon (available through Issuu).

There is a teacher guide for this book with lots of suggested activities, by Ecocreative.


Investigate the Ramsar Convention on Wetlands of International Importance.

The Red-Necked Stint.

Red-Necked Stint on the Atlas of Living Australia.

Research and make maps showing the migratory path of Red-Necked Stints (or other birds using Ramsar wetlands).


Using this resource, students can select a region to explore. They can discover more about what lives in wetlands near them.

Atlas of Living Australia.

Starting with Macquarie Marshes (left menu of Directory of Important Wetlands), students can see records of all the species found there (that have been reported).


Research how rivers and wetlands are managed within the Murray–Darling Basin. Access images of ecologically significant sites in the Basin.

The Murray–Darling Basin Authority: Water for the Environment.

Images of significant sites are available on this website for primary aged students. The website content suits high school students and is included as an extension for students interested in learning about how rivers and wetlands are managed and the current state of iconic sites in the River Murray system.

Field trip/survey

If you have a local river or wetland that is accessible, students can survey for macroinvertebrates.

The Centre for Freshwater Ecosystems has a bug guide and information on how to use the guide to direct your class through a wetland survey. (Local natural resource management organisations may offer relevant field trips or support for locals teachers.)

Students can learn that presence/absence of waterbugs is an indicator of waterway health. Teacher's notes on macroinvertebrate surveying and the SIGNAL macroinvertebrate sensitivity index are available for free download from their website.

First Nations values

Learn about what First Nations people value about the marshes.

NBAN Aboriginal environmental outcomes in the Macquarie Marshes document.

MDBA: Environmental watering priorities.


Find out how Australian researchers count waterbirds.

The UNSW Centre for Ecosystem Centre hosts Dr Richard Kingsford's blog about aerial surveying. The website includes videos Dr Kingsford has made while surveying to count birds in the Murray–Darling Basin.

Aerial survey


Discover wetlands all over Australia and why they are important.

The Department of Climate Change, Energy, the Environment and Water provides information about Australia's wetlands and why they are important.

The Department of Climate Change, Energy, the Environment and Water website describes the value and diversity of wetlands in Australia, links to Ramsar sites and highlights some spectacular places. Students and teachers can use this resource to find local and nationally significant wetlands.


Quiz students on what they know or have learned about wetlands.

Quizlet: wetlands quiz

Teachers can use this digital flashcard quiz to introduce or sum up the value of wetlands. Suitable for high school students.


Discover what fish need to thrive at different stages of their lives.

MDBA website: The Water for the environment section provides an overview of why we need water for the environment and how it is planned for and delivered in the Murray–Darling Basin.

Students review the fish lifecycle to gain understanding of different needs of animals throughout their lives. (The 'Water for the environment' section is an ideal case study for high school students to gain an understanding about decision making for environmental outcomes and how science is used to make those decisions.)


Tour the Macquarie Marshes.

If you're lucky enough to live close to the Macquarie Marshes, you can tour the wetlands.



Research for older students.

Watch the video about the Macquarie Marshes and how they have been affected by development and water management decisions. Also, see extra material about the Macquarie Marshes.

These resources are suitable for high school students looking at effects of environmental decision making and sustainability.

Updated: 22 Jul 2022