River and creek environments fact sheet | Field of Mars EEC

What are river and creek environments?

River and creek environments are freshwater places where water moves through the landscape. They include the flowing water, creek bed, river banks, pools, rocks, logs, soil, leaf litter, shade and plants that grow beside the water.

A river or creek environment is larger than one habitat. It can include many smaller habitats, such as a shaded pool, a muddy bank, a submerged log, a rocky riffle or a patch of reeds. When the living things and non-living features interact, they form part of a waterway ecosystem.

At Field of Mars Reserve and nearby parts of the Lane Cove River catchment, creekline vegetation, wet areas, mangroves and salt marsh help connect bushland, freshwater habitats and estuary environments.

A river and creek environment.

The Lane Cove River catchment includes creeks, pools, banks and riparian vegetation.

Where are river and creek environments found?

River and creek environments are found across NSW, from mountain streams and tableland creeks to lowland rivers, coastal waterways and urban catchments. Some flow all year, while others may become shallow, still or dry during long periods without rain.

In Sydney, many creeks flow through bushland, parks, streets, drains and reserves before joining larger rivers or estuaries. Field of Mars Reserve is part of the Lane Cove River catchment, where water, soil, plants and animals are connected across the wider landscape.

Many Sydney waterways flow through bushland and urban catchments.

What living and non-living features make up river and creek environments?

Living features include algae, aquatic plants, sedges, rushes, riparian trees, shrubs, insects, spiders, worms, crustaceans, fish, frogs, turtles, birds, fungi and bacteria. Plants growing beside creeks help shade the water, hold soil in place and add leaves, bark and branches to the food web.

Non-living features include water, sunlight, temperature, oxygen, nutrients, rocks, sand, gravel, mud, logs, leaf litter and the shape of the creek bed and banks. These features affect how fast water flows, how much shelter is available and which living things can survive there.

Rocks, shade, flowing water and damp plant growth create many small habitats along creeks.

What plants and animals live in river and creek environments?

River and creek environments support many plants and animals. Algae and aquatic plants grow in or near the water. Trees, shrubs, ferns, grasses, sedges and rushes may grow along the banks, especially where soil stays damp or shaded.

Animals use river and creek environments in different ways. Frogs may lay eggs in still or slow water. Dragonfly and damselfly nymphs live underwater before becoming flying adults. Turtles, ducks and other waterbirds may feed, rest or breed in nearby water habitats, while many small invertebrates live among leaf litter, mud, rocks and submerged plants.

Dragonflies hunt near fresh water, while their young live underwater as nymphs.

How do living things depend on river and creek environments?

Living things in river and creek environments are connected through food chains and food webs. Algae and aquatic plants are producers because they use sunlight to make food. Tadpoles, snails, insect larvae and some fish eat plants, algae or small particles in the water. Frogs, dragonflies, turtles, fish and birds may eat smaller animals.

Decomposers, such as fungi and bacteria, break down dead leaves, wood and animal remains. This returns nutrients to the water and soil. Fallen leaves, shaded pools, logs and muddy edges can all become important parts of the food web.

Fallen leaves, logs and wet soil help provide food and shelter for decomposers and small animals.

How are river and creek environments connected to Aboriginal Peoples and Country?

The Wallumedegal of the Darug Nation are the Traditional Custodians of the Ryde area, including the land now known as Field of Mars Reserve. Wallumedegal Country is generally accepted as being on the northern side of Parramatta River, with strong connections to the Lane Cove River, river flats, creeks and mangrove areas.

These water places hold thousands of years of memories, with many sacred places and stories along rivers and in waterholes. Evidence of Aboriginal use of rivers as a food source can be seen in shell middens found on local Country. Rivers and creeks continue to be important places for culture, learning and caring for Country.

Shell middens near waterways can show long connections between Aboriginal Peoples, food, water and Country.

Why are river and creek environments important?

River and creek environments provide water, shelter, breeding places and feeding areas for many living things. They help connect habitats across the landscape, allowing animals to move between bushland, wetlands, mangroves, salt marshes and estuaries.

Healthy creek banks and riparian plants help hold soil in place, reduce erosion, shade the water and improve water quality. River and creek environments also help students learn about living and non-living features, food webs, fieldwork, water quality and how people can care for local places.

Healthy river plants help shade water, hold soil in place and provide habitat for rakali and other small animals.

What threatens river and creek environments?

River and creek environments can be damaged when natural water flow is changed, creek banks are cleared, weeds spread, rubbish enters waterways or soil washes into the water. Stormwater can carry oil, fertiliser, chemicals, soil, leaves and litter from streets, gardens and drains into creeks and rivers.

Too many nutrients can cause algal blooms, especially in slow or still water. Climate change, drought, heatwaves, bushfire, invasive species and loss of riparian vegetation can also place pressure on waterway plants, animals and food webs.

Restoring wet areas and planting native vegetation can help protect waterways.

How can you help protect river and creek environments?

You can help protect river and creek environments by keeping rubbish, soil, oil, fertiliser, chemicals and pet waste out of drains and waterways. Stay on tracks, leave rocks, logs, leaf litter and plants in place, and avoid entering creek beds unless you are with an adult for approved fieldwork.

At home and school, people can plant local native species where suitable, reduce erosion, pick up litter, keep cats contained, keep dogs on leads near bushland and never feed ducks bread. Families, schools and community groups can also support bushcare, waterway care and local habitat restoration projects.

Stormwater basins help slow and manage runoff before it reaches creeks and rivers.

Related fact sheets

Environments and ecosystems

• Ecosystem and environment fact sheets⁠ – Explore Field of Mars EEC fact sheets about ecosystems, environments, food webs and interdependence.
• Field of Mars Reserve fact sheet⁠ – Learn about the reserve, its habitats, ecosystems, waterways, plants, animals and management.
• Water habitats fact sheet⁠ – Learn about ponds, creeks, puddles and wet areas that support frogs, insects, birds and turtles.
• Habitat fact sheet⁠ – Learn how living and non-living features create places where organisms can survive.

Habitats and ecosystems

• Mangrove forest ecosystem fact sheet⁠ – Learn about tidal forests where freshwater, salt water, mud and estuary life meet.
• Coastal salt marsh ecosystem fact sheet⁠ – Learn about low coastal wetlands connected to estuaries, tides and waterbirds.
• Eucalypt forest ecosystem fact sheet⁠ – Learn about bushland ecosystems that connect ridges, slopes, gullies and creeklines.

Plants that support waterways

• Paper-bark tree fact sheet⁠ – Learn about a wetland and creekline plant that provides shelter and habitat.
• Swamp she-oak fact sheet⁠ – Learn about a tree that grows near wet places and supports wildlife.

Animals that use river and creek habitats

• Eastern snake-necked turtle fact sheet⁠ – Learn about a freshwater turtle that uses ponds, creeks and wetlands.
• Pacific black duck fact sheet⁠ – Learn about a waterbird that feeds and shelters in wetland and creek habitats.
• Rakali fact sheet⁠ – Learn about an Australian rodent that hunts aquatic animals.
• Striped marsh frog fact sheet⁠ – Learn about a frog that breeds in still or slow-moving water.

Food webs and ecological relationships

• Dragonfly fact sheet⁠ – Learn about a freshwater insect with aquatic young and flying adults.

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