The ACT Government is improving Canberra's urban waterways with the development of a number of urban wetlands. Newly built water bodies include:
These wetlands provide a range of benefits such as:
NEXT COMMUNITY EVENT - Weeding Bee - Sunday 1 December 2013 - 4-6pm
Followed by a bbq afterwards (RSVP to firstname.lastname@example.org to assist with catering)
Bring a hat, enclosed shoes, gloves, weeding tools (if you have them)
Using wetlands in urban areas is one of the most environmentally effective ways to improve the quality of stormwater. One of the most common causes of poor water quality is suspended solids. Wetlands slow the flow of water (as opposed to fast flowing concrete channels) allowing solids to settle. Wetland plants and sediment bind phosphorus and nitrogen removing these contaminants before the water is discharged.
Water quality data was collected for the Eco-pond at Norgrove Park over 2008-2011 indicating how successful wetlands can be. Results showed that the pond and wetlands reduced:
The eco-pond also trapped:
Units at the Kingston Foreshore overlook Norgrove Park. Note the dense reed beds in the middle ground.
Image: Edwina Robinson
Shallow water zones, planted with local macrophytes (reeds) filter nutrients from the water at Norgrove Park.
Image: Edwina Robinson
Feeding ducks processed food, like bread might seem kind, however it
One of the most common ducks that frequents the constructed wetlands are Black Ducks or Anas superciliosa. Black Ducks can be identified by a dark facial stripe that runs through their eye. It looks like eye liner. Their diet is mainly vegetable matter, particularly sedges, smart weeds and grasses, with a large proportion of seeds. Around one third of Black Duck diet can be made up of freshwater insects.
A Black Duck captured at the Dickson wetland.
Image: Mark Jekabsons
Other birds commonly seen at the wetlands are: Wood Ducks, Grebes (Australasian and Hoary-Headed), Hardhead or White-Eyed Duck and Little Pied Cormorant. Wood Ducks are a grazing duck and enjoy grazing on grasses, clovers, smart weeds as well as wetland plants. Often seen on perches in the wetland, is the diving bird, the Little Pied Cormorant. It feeds on crustaceans like Yabbies and Freshwater Shrimps and fish. The Hardhead is also a bird that enjoys protein. It prefers deeper water and dabbles for animal material, particularly molluscs. The Grebes share a smilar diet and eat water beetles, small fish and larvae.
The ACT Government is working with a small group of volunteers from the Dickson Wetland Carers to produce a brochure of the twelve most common birds encountered at the wetlands. It will include waterbirds as well as birds that use the edge of the wetland or fly over the water feeding on insects.
Lintermans, Mark and Osborne, William (2002) 'Wet and Wild: a field guide to freshwater animals of the Southern Tablelands and High Country of the ACT and NSW'. Environment ACT: Canberra.
Sullivans Creek once consisted of ponds, floodplains and rocky incised gullies. While the catchment restoration does not aim to mimic this historical form it does provide enhanced urban biodiversity by creating a series of planted ponds linked by fingers of vegetation.
Dragonfly. Image: Mark Jekabsons
Wood ducks. Image: Mark Jekabsons
Plovers. Image: Mark Jekabsons
While you might be lucky enough to spot a tortoise or a pied cormorant at your local wetland, chances are Gambusia holbrooki or Mosquito Fish will be present in vast numbers. These small fish - they only grow to 6cm - were introduced from America. Like many stories of introducing species from foreign places, Gambusia breed crazily fast and suffer little predation. They eat native fish, macroinvertebrates and tadpole larvae. Gambusia were introduced because it was thought they did a good job controlling mosquitos.
Research has shown that well designed wetlands without stagnant pockets of water and with good native fauna do a better job for keeping mosquitos in check. If you have a mosquito problem at your place – go round and throw out all the stagnant water that forms in plant saucers and non-circulating water features.
So what can we do about Gambusia?
The ACT Environment and Sustainable Development Directorate and the ACT Education and Training Directorate have produced a 56 page coloured booklet on constructed and natural wetlands. Units of work are provided for early childhood, later childhood, early adolescence and later adolescence. They focus on three essential learning achievements:
ELA 2 - The student understands and applies the inquiry process
ELA 19 - The student understands and applies scientific knowledge
ELA 20 - The students acts for an environmentally sustainable future
These units build understanding of what a wetland is and the place of wetlands in larger systems. They explore the practice of managing urban stormwater by constructing urban wetlands.
In order to understand that the Canberra region hosts a diverse array of wetlands, information is provided on sites such as the Jerrabomberra Wetlands, Ginini Flats, Nursery Swamp, Horse Park and Lake George. A case study focuses on the David St, O'Connor urban wetland, constructed in 2001.
Discovering wetlands in Australia (suitable for Years 3 - 6)