Fortifying the foreshore and rehabilitating vegetation boosts biodiversity and educates the community about the island's environmental significance. Despite setbacks, native species are thriving, showing the resilience of the saltmarsh community.
Pirrita Island, found on the Swansea Channel within Lake Macquarie, provides the local community with important recreational and environmental values. It is made up of a nature reserve containing mangrove and salt marsh habitat that provides refuge for many species, including migratory birds.
The eastern foreshore of Pirrita Island has experienced significant erosion, which, over time, has resulted in the landward movement of the foreshore. The degraded and landward movement of the foreshore has threatened the endangered ecological communities that occur there, including Coastal Saltmarsh and Swamp Oak Floodplain Forest.
Endangered ecological communities are also at risk due to the range of significant weed species that are present. To address these issues, the council partnered with the Department of Climate Change, Energy, the Environment and Water. It jointly funded a project to undertake foreshore protection works and riparian vegetation restoration.
The project involved the installation of rock revetments and rock fillets to relieve the existing foreshore erosion and encourage mangrove and saltmarsh restoration along the northern and eastern foreshore of Pirrita Island. Along the eastern foreshore, rehabilitation of the existing Coastal Saltmarsh and Swamp Oak Floodplain Forest has been carried out at priority sites, and this involved targeted weed removal and revegetation.
Overall, the project aims to reduce weed threats, improve habitat and conservation values of the wetland areas, reduce coastal erosion changes to the foreshore and increase community understanding of the ecological values of the area through the installation of educational signage.
In the long term, it is envisioned that the improved habitat values and reduced threats will help ensure the wetland and saltmarsh can continue to provide vital ecosystem services such as filtering water and providing nurseries for fish species.
This project has had many successes so far; however, one setback has been the damage sustained to areas of the revegetation works due to public interference. A notable positive outcome of this project has been that native species have been spreading in some areas, which may show the resilience of saltmarsh communities.
Recently a new boardwalk was installed on Pirrita Island with funding from the NSW Public Spaces Legacy Program. This boardwalk provides improved community access and will allow the public to explore the island's unique landscape and view the works completed as part of this project.
Aerial view of Pirrirta Island