Theme 1: Water & Catchments

Topic: Wetlands

What is a wetland?

Wetlands are usually areas of fresh, brackish or salty water that are typically shallow, slow moving or static. Wetlands can be temporary, seasonal or permanent in nature and can be either naturally occurring or man made. Wetlands are generally well vegetated and provide a refuge for a diverse range of wildlife.

Types of wetlands

There are three main types of wetlands:

1. Coastal and marine – including:

• Permanent shallow marine waters (e.g. Streaky Bay)
• Estuarine waters (e.g. Onkaparinga estuary)
• Tidal mud, sand or salt flats (e.g. Coffin Bay coastal wetland system)
• Coastal brackish/saline lagoons (e.g. the Coorong)

2. Inland wetlands – including:

• Freshwater marshes (e.g. Swan Reach Wetland complex)
• Freshwater springs (e.g. Great Artesian Basin)
• Subterranean wetlands (e.g. Ewens Ponds and Picanninie ponds)
• Seasonal/intermittent saline lakes (Lake Eyre)
• Seasonal/intermittent freshwater lakes (e.g. Banrock Station wetland)
• Permanent Freshwater lakes (e.g. Lake Bonney, Lakes Alexandrina and Albert)

3. Man-made wetlands – including:

• Water storage areas (e.g. Mount Bold Reservoir)
• Wastewater treatment areas (ie: Greenfield wetlands)
• Stormwater treatment areas (e.g. Morphettville Racecourse wetland)
• Conservational value (e.g. Woorabinda dam)

The importance of wetlands

Wetlands provide a variety of functions and benefits to the community and the surrounding environment. Some of these benefits include:

• Water purification - Plants, animals and soils in wetlands play a significant role in cleaning the water and removing excessive nutrients that are associated with stormwater and agricultural runoff.
• Groundwater replenishment - Many wetlands help to recharge underground aquifers and this is vital for maintaining these water supplies.
• Flood prevention - Wetlands help to act as water storage devices, reducing the potential for floods.
• Biodiversity - Freshwater wetlands hold more than 40% of the world's species. This means they are as productive as coral reefs and rainforests. Coastal wetlands provide homes and breeding grounds for hundreds of migratory birds. Macro invertebrates are usually also very diverse in wetlands, as well as frogs and other animal species.
• Recreation/tourism/economy - Wetlands also provide significant recreational and tourism value. Tidal wetlands and mangrove swamps provide a breeding ground and nursery area for many commercial fish species. Fishing, boating, bird watching and camping are just a few of the recreational pursuits for which wetlands are used.
• Cultural significance - To indigenous Australians, many wetlands and their immediate surrounds provide great spiritual or cultural significance. These include burial places, former campsites, or places where traditional hunts once took place.

Threats to wetlands

Since European settlement, more than 50% of Australia’s wetlands have been exploited for uses such as agriculture and urban development. There are a range of activities which can impact on wetland health. These include such things as: poor agricultural practices, construction, introducing non-native species (both flora and fauna), stream channelisation, land clearance adjacent to the wetlands, and increased nutrient loading.

Wetlands - the natural vacuum cleaner

Wetlands are crucial to the health of our waterways because they remove pollution through a number of natural processes, including:

Sedimentation: Most pollutants in stormwater are absorbed onto sediment like sand, silt or clay. Pollutants such as heavy metals and chemicals tend to bind to this sediment, which appear as silt and mud in a wetland system.

Filtering: Wetlands remove pollutants by filtering water slowing through gravel and aquatic plants, especially reeds. Aquatic vegetation like reed beds slows the flow of water and pollution trapped in sediments sticks to the vegetation.

UV Radiation: Ultraviolet rays from the sun can kill harmful pathogens such as bacteria in shallow water where the rays can penetrate through the water to the bacteria.

Student Activity Ideas

• Create a large wetlands mural in your classroom to show some of the wetland features. Get students to illustrate the different flora and fauna you might find at a nearby wetland.
• Develop a wetland food web.

Enquiry Learning

• What are the different types of wetlands?
• What role in the environment do wetlands play? What ecosystem services, such as nurseries for aquatic life and water quality maintenance, do they provide?
• How might introducing a new species of frog, for instance, affect your local wetland area?

Internet Resources

Type	Description	Resources Covering the Topic
Easy	Wetlands and nature. Brief summary of the role of wetlands.	EPA USA www.epa.gov/owow/wetlands/ vital/nature.html
	How do wetlands work?	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/why_wetlands/3.htm
	Introduction to wetlands and activities for early primary and primary.	Onkaparinga Catchment Water Management Board Catchment Connections www.onkaparinga.net/education/ folder_2.shtml#wild
	Wetland poster. With brief information about the different types of wetlands, including sketches.	US Geological Survey water.usgs.gov/outreach/poster2/ Poster2.html
	Clever wetland interactives that shows the different parts of a wetland and explains its function.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ interactive/wetland/wetland.htm www.cwmb.sa.gov.au/kwc/ programs/why_wetlands/3.htm
	Water backgrounder. Surface waters, rivers (and floodplains), lakes, riparian zones and wetlands. Comprehensive look at the different environments.	NSW EPA www.epa.nsw.gov.au/soe/soe2000/ bw/bw_1.htm#bw_1_h010
	Wetlands depend on us. Downloadable PDF. Thoroughly covers issues. What is a wetland? Wetlands as important places for animals, plants and other organisms. Wetlands are a wasted resource. Diagrams on how wetlands work. Artificial wetlands and how they work.	Murray Users www.murrayusers.sa.gov.au/pdfs/ MIssues2wetlands.pdf
More Complex	An introduction to wetlands. PDF download. Comprehensive overview with diagrams, life cycles, human use and much more.	WA Government Water Resources Commission www.wrc.wa.gov.au/public/ waterfacts/16_wetlands/ livingwetlands.pdf

Activities

Band	Activity	Contact
Early Years	'A Bug's Life. Learn how aquatic invertebrates are used as indicators of water health.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/a_bugs_life/index.htm
	Introduction to wetlands, background information and activities.	Onkaparinga Catchment Water Management Board www.onkaparinga.net/education/ folder_2.shtml#inland
	'Something Fishy'. Find out why native fish populations are threatened. Understanding the importance of habitat, pollution and exotic animals.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/something_fishy/index.htm
	'A Frog's Life'. Learn about biological monitoring and why frogs are used as indicators of water health. Participate in an activity to investigate the mating calls of frogs. Information about the EPA's frog census. Offered in Upper and Lower Murray.	River Murray Waterwatch www.rivermurray.sa.gov.au/ work/curric_resource.html
Primary Years	Macroinvertebrate monitoring. Outdoor sampling and indoor lessons involving video microscopes. Look at bioindicators and water quality.	North Adelaide and Barossa Catchment Water Management Board www.nab.waterwatch.org.au/
	Clever wetland interactive that shows the different parts of a wetland and explains its function.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ interactive/wetland/wetland.htm
	'A Bug's Life'. Learn about biological monitoring and how aquatic invertebrates are used as indicators of water health.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/living_waterways.htm
	'A Frog's Life'. Learn about biological monitoring and why frogs are used as indicators of water health.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/living_waterways.htm
	Introduction to wetlands, background information and activities. Early primary and primary resources.	Onkaparinga Catchment Water Management Board www.onkaparinga.net/education/ folder_2.shtml#inland
	Why wetlands? The role of wetlands in improving water quality and provision of habitat.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/why_wetlands/info.htm
Middle Years	'A Bug's Life'. Learn about biological monitoring and how aquatic invertebrates are used as indicators of water health.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/living_waterways.htm
	Why wetlands? The role of wetlands in improving water quality and provision of habitats.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/why_wetlands/info.htm
	'A Frog's Life'. Learn about biological monitoring and why frogs are used as indicators of water health.	KESAB Patawalonga and Torrens Waterwatch www.cwmb.sa.gov.au/kwc/ programs/living_waterways.htm
	Introduction to wetlands, background information and activities.	Onkaparinga Catchment Water Management Board www.onkaparinga.net/education/ folder_2.shtml#inland
	Coastal and wetland forests. Fact sheet.	Qld Government www.nrm.qld.gov.au/factsheets/pdf/ forest/F08.pdf

Who Can Help?

Organisation	Who Can Help?
All catchments	EPA Community Monitoring Section (including Waterwatch and Frog Census)
Adelaide Metropolitan Area	Urban Forest Biodiversity Program
Metropolitan Catchment Water Management Boards	Catchment Care - North Adelaide and Barossa Catchment Water Management Board (CWMB) Our Patch - Patawalonga and Torrens CWMBs Our Patch - Onkaparinga CWMB

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