Kooragang Ramsar Wetland Ecological Character Description
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Kooragang Ramsar Wetland Ecological Character Description Citation Brereton, R., and Taylor-Wood, E., 2010, Ecological Character Description of the Kooragang Component of the Hunter Estuary Wetlands Ramsar Site. Report to the Department of Sustainability, Environment, Water, Population and Communities (SEWPAC), Canberra. Acknowledgments The Steering Committee provided information and support to the ECD preparation: Chris Herbert and Ann Lindsey, Hunter Bird Observers Club Alison Curtin, Waters and Wetlands Strategy Unit, NSW Office of Environment and Heritage (OEH) Jo Erskine, Parks & Wildlife Group, OEH Simon Godschalx, Wetlands Section, SEWPAC Peggy Svoboda, Kooragang Wetland Rehabilitation Project, Hunter-Central Rivers Catchment Management Authority The ECD development was funded by SEWPAC. Introductory Notes This Ecological Character Description (ECD Publication) has been prepared in accordance with the National Framework and Guidance for Describing the Ecological Character of Australia’s Ramsar Wetlands (National Framework) (Department of the Environment, Water, Heritage and the Arts, 2008). The Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) prohibits actions that are likely to have a significant impact on the ecological character of a Ramsar wetland unless the Commonwealth Environment Minister has approved the taking of the action, or some other provision in the EPBC Act allows the action to be taken. The information in this ECD Publication does not indicate any commitment to a particular course of action, policy position or decision. Further, it does not provide assessment of any particular action within the meaning of the Environment Protection and Biodiversity Conservation Act 1999 (Cth), nor replace the role of the Minister or his delegate in making an informed decision to approve an action. 1 The Water Act 2007 requires that in preparing the [Murray-Darling] Basin Plan, the Murray Darling Basin Authority (MDBA) must take into account Ecological Character Descriptions of declared Ramsar wetlands prepared in accordance with the National Framework. This ECD Publication is provided without prejudice to any final decision by the Administrative Authority for Ramsar in Australia on change in ecological character in accordance with the requirements of Article 3.2 of the Ramsar Convention. Disclaimer While reasonable efforts have been made to ensure the contents of this ECD are correct, the Commonwealth of Australia as represented by the Department of Sustainability, Environment, Water, Population and Communities does not guarantee and accepts no legal liability whatsoever arising from or connected to the currency, accuracy, completeness, reliability or suitability of the information in this ECD. Note: There may be differences in the type of information contained in this ECD publication, to those of other Ramsar wetlands. Photo Credits OEH – Red Flowers at Kooragang wetlands, NSW OEH – Water and Mangroves at Kooragang wetlands, NSW Geoff Woods© – Kooragang wetlands at Stockton, NSW OEH – Water and Mangroves at Kooragang wetlands, NSW 2 Executive summary This ecological character description (ECD) is for the Kooragang component of the Hunter Estuary Wetlands Ramsar site which is located in the estuary of the Hunter River at Newcastle on the central coast of New South Wales. The purpose of the ECD is to provide a baseline description of the site at the time of Ramsar listing, such that changes in ecological character can be assessed. The Hunter Estuary Wetlands Ramsar site is comprised of the Kooragang component of the Hunter Wetlands National Park (formerly Kooragang Nature Reserve) which was listed in 1984 and Shortland Wetlands (now called the Hunter Wetlands Centre Australia) which was added to the Ramsar site in 2002. The Hunter Wetlands Centre Australia is a small (42 hectare) complex of wetlands located approximately 2.5 kilometres south west of Kooragang. Kooragang Nature Reserve was included in the Hunter Wetlands National Park which was gazetted in 2006. The Kooragang component of the Hunter Estuary Wetlands Ramsar site is located approximately seven kilometres north of the Newcastle central business district on the ‘North Arm’ of the Hunter River and covers an area of 2926 hectares. The Ramsar site is comprised of the bed of Fullerton Cove, the northern part of Kooragang Island (including the Kooragang Dykes) and the eastern section of the Tomago Wetlands (Figure 2-1). The Tomago Wetlands are an area of former wetlands converted to grazing land by drains and levees which lie to the west of Fullerton Cove. The Ramsar site also includes the fringing mangroves and islands within Fullerton Cove and part of the North Arm, as well as Stockton Sandspit and the Kooragang Dykes. On Kooragang Island, the site is bounded by Ash Island to the west and State owned undeveloped land to the south (Figure 2-1). The undeveloped parts of Kooragang Island which includes Ash Island and the Ramsar site are bounded by a rail line which separates them from the southern industrial area. Ramsar listing criteria The entire Hunter Estuary Wetlands Ramsar site (i.e. the Kooragang component and Hunter Wetlands Centre Australia) was re-assessed against the current Ramsar criteria in 2010 which identified that the wetland met Criteria 2, 4 and 6. The Kooragang component of the Hunter Estuary Wetlands contributes to all of these as outlined below: • Criterion 2. One wetland bird species (Australasian bittern; Botaurus poiciloptilus), listed as Endangered under both the EPBC Act and on the IUCN Red List (Version 2009.1), a fish species (Estuary Stingray; Dasyatis fluviorum) listed as vulnerable on the IUCN Red List (Version 2009.1) 3 and a frog (green and golden bell frog; Litoria aurea) listed as Vulnerable on the EPBC Act have been recorded within the Kooragang component; • Criterion 4. The Kooragang component is an important foraging and roosting site for migratory shorebirds, and supports waterbirds at critical stages in their life cycles, including breeding, migration stop-over, roosting and drought refuge; and • Criterion 6. The Kooragang component regularly supports more than 1% of the East Asian- Australasian Flyway population of eastern curlew (Numenius madagascariensis) and more than 1% of the Australian population of red-necked avocets (Recurvirostra novaehollandiae). Wetland types The Kooragang component of the Hunter Estuary Wetland contains five Ramsar wetland types: • estuarine waters (F) • inter-tidal mud, sand or salt flats (G) • Inter-tidal marshes; includes salt marshes, salt meadows, saltings, raised salt marshes; includes tidal and brackish marshes (H) • Inter-tidal forested wetlands; includes mangrove swamps, tidal and freshwater swamp forests (I) • tree-dominated wetlands (Xf) Critical components and processes The critical ecosystem components, sub-components and processes that describe the ecological character of the Kooragang component at the time of listing have been determined to be: • waterbirds, particularly migratory shorebirds • the green and golden bell frog (Litoria aurea), a nationally listed threatened species • Sarcocornia saltmarsh which supports migratory shorebirds • intertidal mudflats which provide foraging habitat for migratory shorebirds • hydrology (tidal regime and freshwater inflows) which is a major influence on the distribution and extent of saltmarsh and mangroves A brief description of the ecosystem components and processes present at the time of listing is provided in Table E1. 4 Table E1. Components and processes within the Hunter Estuary Wetlands Ramsar site Component/process Summary description Geomorphology The Hunter Estuary is a “mature barrier estuary” which is characterised by an extensive river system with a high sediment load. Hydrology Large catchment (22 000 kilometres2), with stream inflows of approximately 1800GL/yr. There is no strong pattern of seasonal freshwater flows into the estuary. The majority of inflow and outflows in the estuary are tidal fluxes. The annual tidal inflow and outflow for the Hunter Estuary have been estimated to be 18 250GL. Water quality Water quality data at time of listing was limited, however the indications are that: • salinity is variable and typical of an estuary where salinity is affected by freshwater inflow events • estuary waters are well oxygenated and are likely to be maintained by the strong tidal movements in the lower estuary • turbidity levels in the estuary are generally moderate, with short-term increases after rain events • nutrient levels (nitrogen and phosphorus), particularly phosphorus, are relatively high in the estuary • heavy metals are not particularly concentrated in the North Arm and Fullerton Cove • the phytoplankton is typical for an estuary of the mid-east coast of Australia and is dominated by diatoms and dinoflagellates with a total of 20 taxa Vegetation The vegetation communities within the site are predominantly wetland types, including mangrove forests, saltmarsh, and brackish swamps. Successional changes were happening in the vegetation within the site at the time of listing, in particular, the expansion of mangroves and decline in saltmarsh. Birds The Hunter Estuary Wetlands supports an abundance and diversity of wetland birds including migratory and non-migratory shorebirds. The Hunter Estuary Wetlands supports waterbirds at all stages in their life cycles, including breeding, migration stop-over, roosting and drought refuge which is one of the main reasons why the Hunter Estuary Wetlands