Nature conservation

Threatened species

Freshwater Wetlands on Coastal Floodplains of the New South Wales North Coast, Sydney Basin and South East Corner Bioregions - profile

Indicative distribution


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Key:
known
predicted
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Freshwater Wetlands on Coastal Floodplains of the New South Wales North Coast, Sydney Basin and South East Corner Bioregions
Conservation status in NSW: Endangered Ecological Community
Commonwealth status: Not listed
Gazetted date: 17 Dec 2004
Profile last updated: 01 Aug 2018

Description

Associated with coastal areas subject to periodic flooding and in which standing fresh water persists for at least part of the year in most years. Typically occurs on silts, muds or humic loams in low-lying parts of floodplains, alluvial flats, depressions, drainage lines, backswamps, lagoons and lakes but may also occur in backbarrier landforms where floodplains adjoin coastal sandplains. Generally occur below 20 m elevation on level areas. They are dominated by herbaceous plants and have very few woody species. The structure and composition of the community varies both spatially and temporally depending on the water regime: Those that lack standing water most of the time are usually dominated by dense grassland or sedgeland vegetation, often forming a turf less than 0.5 metre tall and dominated by amphibious plants including Paspalum distichum (water couch), Leersia hexandra (swamp rice-grass), Pseudoraphis spinescens (mud grass) and Carex appressa (tussock sedge). Where they are subject to regular inundation and drying the vegetation may include large emergent sedges over 1 metre tall, such as Baumea articulata, Eleocharis equisetina and Lepironia articulata, as well as emergent or floating herbs such as Hydrocharis dubia (frogbit), Philydrum lanuginosum (frogsmouth), Ludwigia peploides subsp. montevidensis (water primrose), Marsilea mutica (nardoo) and Myriophyllum spp. (milfoils). As standing water becomes deeper or more permanent, amphibious and emergent plants become less abundant, while floating and submerged aquatic herbs become more abundant. These latter species include Azolla filiculoides var. rubra, Ceratophyllum demersum (hornwort), Hydrilla verticillata (water thyme), Lemna spp. (duckweeds), Nymphaea gigantea (giant waterlily), Nymphoides indica (water snowflake), Ottelia ovalifolia (swamp lily) and Potamageton spp. (pondweeds). The threatened aquatic plants, Aldrovanda vesiculosa and Najas marina, also occur within this community. For a comprehensive list of species that characterize the community open the Scientific Determination link in the top right box.

Distribution

Known from along the majority of the NSW coast. However, it is distinct from Sydney Freshwater Wetlands which are associated with sandplains in the Sydney Basin bioregion. Extensively cleared and modified. In the 1990s the extent remaining were: 3% in the NSW North Coast bioregion, 66% in the lower Hunter – Central coast region, 40% on the Cumberland Plain, 70% in the Sydney – South Coast region, and 30% in the Eden region. There is less than 150 ha remaining on the Tweed lowlands (estimate in 1985); about 10,600 ha on the lower Clarence floodplain (in 1982); about 11,200 ha on the lower Macleay floodplain (in 1983); about 3,500 ha in the lower Hunter – Central Hunter region (in 1990s); less than 2,700 ha on the NSW south coast from Sydney to Moruya (in the mid 1990s), including about 660 ha on the Cumberland Plain (in 1998) and about 100 ha on the Illawarra Plain (in 2001); and less than 1000 ha in the Eden region (in 1990). Poorly reserved, known to occur in Ukerebagh, Tuckean, Tabbimoble Swamp, Hexham Swamp, Pambalong and Pitt Town Nature Reserves and Bungawalbin, Scheyville and Seven Mile Beach National Parks.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.


Threats

Recovery strategies

Activities to assist this species

Information sources

IBRA Bioregion IBRA Subregion Known or predicted Geographic restrictions region
NSW North CoastCoffs Coast and Escarpment Known None
NSW North CoastKaruah Manning Known None
NSW North CoastMacleay Hastings Known None
NSW North CoastYuraygir Known None
Other StateJervis Bay Territory Known None
South East CornerBateman Known None
South East CornerEast Gippsland Lowlands Known None
South East CornerSouth East Coastal Ranges Known None
South Eastern QueenslandBurringbar-Conondale Ranges Known None
South Eastern QueenslandClarence Lowlands Known None
South Eastern QueenslandClarence Sandstones Known None
South Eastern QueenslandScenic Rim Known None
South Eastern QueenslandSunshine Coast-Gold Coast Lowlands Known None
Sydney BasinCumberland Known None
Sydney BasinHunter Known None
Sydney BasinIllawarra Known None
Sydney BasinJervis Known None
Sydney BasinPittwater Known None
Sydney BasinSydney Cataract Known None
Sydney BasinWyong Known None
Sydney BasinYengo Known None