We recognise the importance of innovation in everything we do, including the way we manage the environment
Recently, we completed the construction of a highly adaptive and exciting project to restore tidal habitat for endangered migratory shorebirds at Ash Island. To do this, we partnered with specialists in wetland ecology to come up with the smartest way to manage the habitat into the future.
Newcastle Coal Infrastructure Group sought the expertise of the Water Research Laboratory (WRL) at the University of New South Wales - www.wrl.unsw.edu.au. The WRL has extensive experience in restoring wetlands and aquatic ecosystems up and down the New South Wales coast, including for environmental and land use purposes. The WRL assisted NCIG in designing two key aspects of the shorebird habitat, including:
- A tidal “Smart Gate” – an automated flood gate which can manage tides within the habitat system
- A Mangrove Propagule Exclusion Device (MPED) – a removable screen to prevent the intrusion of mangrove seeds into the system.
These devices were designed in consultation with the WRL and selected manufacturers. The result is a tidal channel which can be slowed or stopped to achieve ideal conditions for saltmarsh, mud and shorebirds inside the wetland. Specifically, the system now has:
- A Smart Gate made up of two sliding panels which can be operated remotely and is powered locally via a small solar panel arrangement. The gates can be closed to either reduce the tide in the wetland or capture the maximum amount of water possible to create suitable conditions for shorebirds. Reducing the tide height inside the wetland also assists in reducing the potential area that mangroves may reestablish.
- Two MPEDs which block floating mangrove seeds upstream and downstream from the Smart Gate. The primary MPED blocks mangroves during the fruiting season using a fine steel mesh, while large openings are retained at the bottom for fish passage. The secondary MPED is a removable net which captures any seeds that may travel past the first MPED. This is also positioned in the channel so fish can swim freely in and out of the wetland.
Importantly, the management regime and objectives for migratory shorebird will be developed collaboratively with all stakeholders. These include the National Parks and Wildlife Service (NPWS), Hunter Bird Observers Club, Local Land Services (LLS) and other government departments. This will allow all interested parties to buy-in to the outcomes for migratory shorebirds and other important ecological values on Ash Island.
The gates will be operated automatically based on two factors:
- Tide height – closing the gates once the ideal tide height is reached. Tide height is measured using real-time water level sensors
- Time of year – depending on predicted King and Spring Tides, the gates will be scheduled to remain open and allow high water levels inside the wetlands. This will assist in development of endangered saltmarsh communities.