Wetlands are areas of shallow water that are usually flooded for at least part of the year. They are distributed from the coast to inland areas and may occur at low and high altitudes. They include areas of marsh, fen and peatland, and may be found in streams and around lakes. They may be natural or artificial, permanent or temporary, static or flowing, and be fresh, brackish or salty. On some farms a small wetland may simply be a swampy area that has reeds and rushes. Plants and animals that live in wetlands are adapted to wet conditions for at least part of their life cycle. Many wetlands have dried out during the drought periods of the last 15 years. However, they may refill in the future.
Wetlands are among the world's most productive environments and their continuing loss and degradation is a major global problem. They are vital habitats and breeding grounds for many species, especially fish and waterbirds, some of which are in danger of extinction. They support wildlife that help to control insect pests on farms and provide important refuges for wildlife during drought. Wetlands help to purify water by acting as filters that trap sediment and nutrients. They reduce erosion and provide protection from floods by absorbing and slowly releasing water.
Where to see wetlands
Wetlands with many birds can be seen at Orielton Lagoon, Pittwater and Moulting Lagoon, and on the mudflats at Robbins Passage. Coastal wetlands can be seen at Waterhouse Point, Asbestos Range National Park and Jocks Lagoon near St Helens. Lake Dulverton near Oatlands and Lake Crescent in the Central Highlands are also excellent examples of wetlands.
Biodiversity values of wetlands
Many wetlands have been drained or dammed. In the drier parts of the state almost one-third of the wetlands have been drained and almost one-third have been flooded as dams. Many of the dry country wetlands are of national or international significance, with many listed on the Directory of Important Wetlands in Australia and several listed under the Ramsar Treaty which is an international treaty dedicated to protecting the world's wetlands.
Wetlands are important habitats for many species, including some migratory species such as Lathams snipe (Gallinago hardwickii
). A number of wetland bird species such as the Australasian shoveller (Anas rhynchotis rhynchotis
) and the hard head (Aythya australis
) are thought to be declining in numbers.
Refer to Threatened Species
for more information.
Management issues of wetlands
- Protect remaining wetlands from permanent inundation or drainage.
- Excluding stock is the best option, if possible. It is possible to graze a wetlands with minimal damage when it is completely dry. However, stock should be excluded while the wetlands is drying out. Stock trampling the boggy ground will destroy the vegetation mat that is important for a healthy wetlands.
- Alternative watering points may be needed. If that is not possible it may be necessary to fence off most of the wetlands while still providing access to the most suitable watering point.
- Exclude fire from wetlands
There are numerous plants that grow in wetlands and around their edges. Once a wetlands has been established it is likely that a range of rushes (Juncus
species) and bog rushes (Schoenus
species) will appear.