Estuaries are semi-enclosed waterbodies with open (or intermittently open) connections with the ocean (1). They are the tidal portion of a waterbody, and the area where freshwater draining from the catchment mixes with ocean waters (2)
The Hunter Estuary wetlands are protected by an international agreement called the Ramsar Convention, because it is the home to many threatened and internationally important species.
Newcastle and Port Stephens Councils have signed a Sister Wetland Agreement with six Japanese Councils, called the Kushiro Agreement, to protect Latham’s Snipe (Gallinago hardwickii). This shorebird migrates between the Hunter Estuary and Japan.
Latham's Snipe (Gallinago hardwickii) (Source: NSW DPI)
Shorebirds are birds that are regularly found along our coastal and river shorelines. Some shorebirds are migratory and can travel over 20,000km in a year. The Bar Tailed Godwit has been tracked flying non-stop for 11,700 kilometres over nine days (3).
Our estuary is one of only 20 sites in Australia that forms part of the East Asian-Australasian Flyway (5) a path that migratory shorebirds fly, which extends from Alaska and Russia, down to Australia and New Zealand (6). There are 23 countries within the flyway, and 54 species of migratory shorebirds use the flyway (6). The East Asian-Australasian flyway is one of nine flyways across the world that is used by migratory shorebirds (6).
As migratory shorebirds rely on habitats in different countries to survive, they require international protection. Australia has signed three international agreements to help protect migratory shorebirds, including:
- Japan - Australia Migratory Bird Agreement (JAMBA)
- China - Australia Migratory Bird Agreement (CAMBA)
- Republic of Korea - Australia Migratory Bird Agreement (ROKAMBA).
In Australia, migratory shorebirds are protected by federal legislation called the Environment Protection and Biodiversity Conservation Act 1999.
City of Newcastle is working with the National Parks and Wildlife Service, Hunter Bird Observers Club, Kooragang Wetlands Rehabilitation Project, and others, to ensure the future of shorebirds in our estuary.
The Hunter Bird Observers Club undertook a study in 2007 to identify the bird species that can be found in the Hunter Estuary.
There has been a significant decline in bird population due to local and international habitat loss. In the Hunter Estuary, large areas of mudflats have been lost to land reclamation and the expansion of mangroves, which has considerably reduced the habitat available for shorebirds (7).
Green and Golden Bell Frog
The Green and Golden Bell Frog (Litoria aurea) was once a very common tree frog but is now endangered. The frog population in the Hunter Estuary is under threat from industrial development, increased saline inundation, disease (Chytrid fungus), predation by introduced pests, and poor water quality (9).
Further information about the Green and Golden Bell Frog can be found at the Office of Environment and Heritage website.
Estuarine Shore Crabs
City of Newcastle has developed a guide to the types of crabs that can be found along the shore of our estuary
Key vegetation types found within the Hunter Estuary include:
- Mangroves which are a group of trees and shrubs found in the intertidal zone between the land and river (10)
- Saltmarsh which is a community of grasses, herbs and shrubs found in the intertidal zone (11)
The Hunter Estuary has the largest area of mangroves in NSW, covering 19.217km2 (13). Mangroves provide valuable food and habitat for a range of animals, especially fish.
The Hunter Estuary has the fourth largest area of saltmarsh in NSW, covering 5.204km2 (13). Saltmarsh provides valuable food and habitat for a range of animals, especially birds (including migratory shorebirds).
City of Newcastle, Landcare, and others are undertaking ongoing revegetation works around the estuary. The goals for ongoing revegetation works are to:
- Protect and enhance shorebird habitat
- Protect and enhance native estuarine habitat values, and threatened vegetation species
- Minimise the impacts of weeds and pests.
Some examples of the works City of Newcastle has undertaken are shown below.
- Pirate Point 2014
- Pirate Point 2015
- Stockton Ballast Ground 2013
- Stockton Ballast Ground 2015
A number of significant wetland conservation projects are being undertaken by other stakeholders within the Hunter Estuary including the Hexham Swamp Rehabilitation Project, Kooragang Wetlands Rehabilitation Project and Tomago Wetlands Restoration Project.
To help protect our estuarine plants and animals, please remember to:
- look at estuary creatures (birds, frogs, crabs), but don’t touch
- avoid disturbing the birds
- avoid walking through mangroves and saltmarsh where possible
- take home any discarded fishing tackle and litter.
We have prepared a number of documents to identify the issues impacting on the estuary, and the management actions that should be undertaken to address the issues.
The Hunter Estuary Processes Study provides background information about the estuary (including flora/fauna, water quality, and bank stability) and identifies the key issues impacting on the estuary.
The Hunter Estuary Management Study outlines potential management actions for addressing the key issues impacting on the estuary. The Study was developed after extensive community consultation.
The Hunter Estuary Coastal Zone Management Plan contains the list of agreed management actions that City of Newcastle, and others, aim to implement over time.
The Newcastle Coast and Estuary Vegetation Management Plan prioritises on ground works to protect estuarine plants and animals in Newcastle.
References
(1) NSW Government. (1992). Estuary Management Manual.
(2) Office of Environment and Heritage. (2015). Estuaries of NSW.
(3) Department of Environment (2015). Limosa Lapponica - Bar Tailed Godwit. Retrieved from http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=844
(4) Herbert, C. (2007) Distribution, Abundance and Status of Birds in the Hunter Estuary.
(5) East Asian - Australasian Flyway Partnership. (2015). Flyway Site Network.
(6) Bamford, M., Watkins, D., Bancroft, W., Tischler, G., & Wahl, J. (2008). Migratory Shorebirds of the East Asian - Australasian Flyway; Population Estimates and Internationally Important Sites. Canberra, Australia: Wetlands International - Oceania.
(7) Herbert, C. (2011). Shorebirds in the Hunter Estuary.
(8) Department of Environment and Conservation NSW. (2005). Draft Recovery Plan for the Green and Golden Bell Frog (Litoria aurea). Hurstville, NSW: DEC NSW.
(9) Department of Environment and Climate Change (NSW). (2007). Draft Management Plan for the Green and Golden Bell Frog Key Population in the Lower Hunter. Sydney: Department of Environment and Climate Change (NSW).
(10) NSW Department of Primary Industries. (2008). Primefact 746, Mangroves. Retrieved from http://www.dpi.nsw.gov.au/fisheries/habitat/aquatic-habitats/estuarine#saltmarshimportance
(11) NSW Department of Primary Industries. (2023). Primefact 1256, Coastal Saltmarsh.
(12) NSW Department of Primary Industries. (2007). Primefact 629, Seagrasses.
(13) Creese, R.G., Glasby, T.M., West, G., and Gallen, C. (2009). Mapping the Habitats of NSW Estuaries. Industry & Investment NSW.
(14) Williams, R.J., Watford, F. A., & Balashov, V. (2000). Kooragang Wetland Rehabilitation Project: History of Changes to Estuarine Wetlands of the Lower Hunter River, NSW Fisheries Final Report Series, 22. Cronulla, NSW: NSW Fisheries.