Saltmarsh
What is a Saltmarsh?
Like other natural wetlands, saltmarsh occupies transitional zones between wet and dry land. They are typically found in the upper tidal zone of estuaries and mangrove systems. Saltmarsh survives in a niche created by hyper saline conditions that restricts terrestrial species and even mangroves. They are found in a wide range of climatic conditions from the arctic to the tropics.Saltmarsh typically occurrs between the Mean High Tide and the King or maximum tide. Therefore many saltmarshes in Australia and other parts of the world have been lost to land reclamation initiatives. Saltmarshes are placed under further pressure by sedimentation and stormwater run-off which enable saltmarsh species to be displaced by both mangroves and terrestrial species.
Conserving and Reconstructing Saltmarsh
Australian Wetlands is a leader in the preservation, design and construction of saltmarsh ecosystems. We apply ecological expertise to our in-house design and construction operations to ensure environmentally sound outcomes. Some projects Australian Wetlands has successfully undertaken are detailed below.
- Salt Pan Creek Saltmarsh and Mangrove Restoration
- Settlement Point Shores Saltmarsh
- Saltmarsh Design (Port Stephens) - Tilligery Pastoral Co.
- Saltmarsh Assessment (Port Stephens) - Port Stephens Council
- Tempe Reserve - Marrickville Council
- Duck River Riparian Corridor - DSNR
This project involved the construction, planting and ongoing maintenance of a 1.5ha saltmarsh and mangrove system underneath the M5 freeway in Western Sydney. The primary objective of this project was the rehabilitation of a degraded estuarine environment. Australian Wetlands were associated with Envirocivil in the wetland construction and undertook all saltmarsh planting. The saltmarsh has successfully established and Australian Wetlands maintained the system.
Saltmarsh Planting at Salt Pan Creek
The Settlement Point Shores project, located in Port Macquarie NSW, will be the final canal housing development on the East Coast of Australia. Australian Wetlands was involved in the transplantation of saltmarsh and mangrove habitats located at the site, as part of the Environmental works for the project. The contract required Australian Wetlands staff to transplant large areas of mangroves and saltmarsh vegetation.
Mangroves seedlings were transplanted with a good success rate (~75%). Mangrove embryos were also planted with a lower success rate (~50%). Given the amount of effort required to transplant seedlings the option to use embryos is now considered to deliver better results. Saltmarsh plants (e.g. Juncus kraussii) were transplanted quite successfully, with a strike rate of ~80%. A crucial component of the contract was the ongoing maintenance of the mangrove and saltmarsh areas.
This project involved the design of a wetland treatment system for wastewater from an aquaculture project. Challenges associated with the project included positioning the development at the correct tidal height to create a functioning saltmarsh system.
Australian Wetlands was commissioned by Port Stephens Council to assess the impacts of leachate from a waste depot on saltmarsh vegetation. The project involved botanical identification of saltmarsh species and a statistical assessment of their coverage along a series of transects.
Australian Wetlands was responsible for installing and maintaining the plants for this constructed saltmarsh and wetland area. The project involved the challenge of establishing plants in a harsh environment which also has a high public profile.
Tempe Reserve was opened by Marrickville Council in Spring 2004 as a major recreation area.
Australian Wetlands were responsible for the enhancement and maintenance of several hectares of riparian corridor along the Duck River at Silverwater, NSW.
A range of vegetation communities are represented within the zone, including salt marsh, mangroves, ephemeral wetland and terrestrial.
Australian Wetlands also prepared the Vegetation Management Plan (VMP) for the site, including the endangered saltmarsh species, Wilsonia backhousei.
This site provides a typical example of the manner in which historical land-use has undermined the integrity of saltmarsh communities. Sediment accumulation, stormwater runoff and land reclamation have all impacted upon the site.
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