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Flood Plain Lower Ringarooma River Ramsar site Ecological Character Description March 2012 Blank page Citation


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1.5Components and Processes of the Site


Ecosystem components include the physical, chemical and biological parts of a wetland (Millennium Ecosystem Assessment 2005). Ecosystem processes are dynamic forces and include all those processes that occur between organisms and within and between populations and communities. This includes interactions with the non-living environment that result in existing ecosystems and bring about changes in ecosystems over time (Australian Heritage Commission 2002). They may be physical, chemical or biological.

In practice, many components can also be processes. For example, climate, hydrology and geomorphology can each be viewed as static parts (components) of the sites as well as dynamic forces (processes) that bring about change to wetlands. In this ECD they are considered together.

At a high level, the components and processes of the site include:


  • climate

  • geomorphology

  • substrate

  • hydrology

  • water quality

  • vegetation

  • fauna

Beyond this higher level, each component consists of subcomponents. These are presented and discussed below.

1.5.1Climate


At a global level, all of Tasmania is classified as ‘temperate rainy climate with warm summers’ (Strahler and Strahler 1992). Average annual rainfall varies substantially across the island but at nearby Bridport (approximately 45 kilometres southwest of the site) rainfall has averaged 723 millimetres since records have been kept (13 years). Rainfall peaks in winter (the June average is nearly 95 millimetres), extending through spring, with lowest rainfall in late summer – early autumn (February average rainfall is just over 30 millimetres) (Figure 11). Eddystone (just under 40 kilometres to the southeast of the site) has a substantially longer record and supports the results for Bridport, though with a more even rainfall throughout the year (Figure 11), reflecting Eddystone’s east coast position rather than the north coast location occupied by Bridport and the site.

Within the context of this ECD, the key features of climate would include extremes in natural fluctuations and also possible impacts of climate change. Although neither of these can be controlled, future management of the site may need to consider potential impacts of changes in climate. Of particular importance to the site would be how to manage changes to the volume, seasonality and delivery (magnitude, intensity and frequency) of rainfall events.

Despite the relatively short period of data collection at Bridport, the information provides an important baseline for future comparisons, particularly in relation to climate change and is supported by data derived from nearby Eddystone Point (Figure 11). Figure 12 displays the highest and lowest monthly rainfalls received at Bridport over the 13 years of data collection. There has been substantial variability over the recording period, with both January and June recording monthly rainfalls below 25 millimetres and above 125 millimetres on separate occasions.

Any sea level rise associated with climate change could allow an incursion of estuary waters into the freshwater wetland habitat, impacting on the freshwater biota within the wetlands.




Figure 11: Climograph of Bridport 1994 – 2007 and Eddystone Point 1957 – 2007. (Source: Bureau of Meteorology 2007)



Figure 12: Monthly highest and lowest rainfalls recorded at Bridport 1994 – 2007. Source: Bureau of Meteorology 2007.


1.5.2Geomorphology


Geomorphology of the Ringarooma River catchment is a key feature and a controlling factor of the ecological character of the site. The river originates in a granodiorite massif, passes mostly through granite in its middle reaches and into alluvium in its lower reaches (Nelson 1999). The upper reaches are typified by a cobble-gravel substrate grading to boulder-cobble in the highest reaches (Nelson 1999). The extensive history of alluvial tin mining in the river and surrounding catchment has led to a massive release of sand and silt into the stream. The sand component has been progressing downstream in a large wave of sediment (termed a ‘sand slug’), with the finer and less heavy silts being more rapidly washed downstream. The sand slug has changed the stream bed from gravel-dominated to sand-dominated as the river progressively aggraded (built up) with the sediment. The sand aggradation has increased bed height by more than 10 metres in the lower reaches of the Ringarooma River (Knighton 1991). Upstream supplies of the sediment have gradually been depleted as the sediment is carried downstream by the river. This has led to a subsequent degradation (lowering) of the stream bed. The process of aggradation followed by degradation of the bed is gradually moving downstream.

Degradation has yet to reach the downstream reaches of the Ringarooma, where sediment waves continue to pass over a slightly aggrading bed. In 1991, Knighton predicted that at least another 50 years will be needed for degradation to cleanse the Ringarooma of mining debris. However, Jerie and Houshold (2001) have noted that much of the sediment may not reach the sea, instead being deposited in the wetlands. They note, “the Ringarooma will not be a stable place for some time”. A series of aerial photographs of the site were presented in Jerie and Houshold (2001) which are presented in section 4. Once the degradation of the stream bed reaches the wetlands, it is possible that channel incision will drain pools connected to the stream. The effect on the groundwater hydrology may also be sufficient to affect wetlands not connected to the river (Jerie, personal communication).

Sediment aggradation has been responsible for creating wetlands and filling in wetlands at the site. The site currently contains a mosaic of landforms including dunefields, lunettes, natural levees, active and abandoned stream channels, sand splays from avulsions, as well as a variety of wetlands including lakes, ponds, lagoons and intermittently wet areas (Hydro Tasmania 2003). The area is regularly flooded by overflow from the river. As noted in Section 2.1, the maximum depth of water in The Chimneys is between two and four metres during flooding, whilst the maximum depth of permanent water is between half a metre and one metre (RIS 2005). Observations of the site in late autumn 2007 (in dry conditions) noted depths of approximately half a metre in the few remnant pools in The Chimneys. At the same time, water depths in Shantys Lagoon and Blueys Lagoon were estimated as being approximately two metres, indicating that during flood periods these could be up to six metres deep.

Similar to most wetland complexes, the mosaic of landforms and habitats at the site is a naturally dynamic system. Localised erosion and aggradation shift the depth, hydrologic regime and even the location of the wetland habitats. However, a key consideration for management of this site is that the rate of geomorphic change has been greatly accelerated, and the direction altered, by the massive inputs of mine-derived sediment. The extent to which the mosaic of landforms is maintained by future geomorphic changes will have an effect on the number and variety of wetland habitat types at the site.

Future management decisions may need to address whether the site will be actively managed to maintain its geomorphic diversity (and its Ramsar status), or whether a more passive management regime will be adopted, allowing the system to determine its own form – even if it loses features that contributed to its Ramsar listing.

Beyond the freshwater zone, the estuary zone is wave dominated, with a flood tide delta (Jason Bradbury, personal communication; Coastal Zone Australia Ltd 2005). Geomorphic characteristics of wave dominated deltas typically include the deltas themselves, barriers, mudflats, channels and beaches, and these are found in the Ringarooma estuary. The Ringarooma Estuary and sections of the adjacent coast are also geomorphic features within the site boundary. Mine-derived sediments have filled the estuary and large sand flats now exist where once large ships were able to traverse (Jerie and Houshold 2001).

The geomorphology of the coastline has not been documented (Jerie personal communication). although part of the site is listed on the Tasmanian Geoconservation Database (DPIW 2009) as part of the Northeast Tasmanian Pleistocene Aeolian System.

1.5.3Substrate


Currently, the most important feature of the substrate in the site is its movement within the site and its ongoing accumulation of mining sediment across the site. As well as influencing landform as described above, the mine waste is affecting soil texture. The Holocene Flood Plain sediments, consisting mainly of clays, sands and gravels (RIS 2005), are overlain by silty clay soils, with the silt being derived from the mine waste, and decreasing with depth in the soil profile. Mapping conducted in 2008 indicates a high risk of potential acid sulphate soils in the area.

1.5.4 Hydrology


The hydrology of any wetland is a vital determinant of its ecological character. The season of delivery, the period of inundation for ephemeral wetlands (or water level rises for permanent wetlands), fluctuations in water levels and interannual variations can all affect the ecological character of a wetland. In the Ringarooma wetlands, the hydrology is largely influenced by the interaction between geomorphology and river flows. The timing of delivery and the volumes delivered influence a number of important biotic responses, such as seed germination, triggers for breeding (for birds, fish, frogs), success of breeding, and provision of food.

The hydrology of the site is not well-documented but excellent information is available upstream in the Ringarooma River. There are useful hydrological flow data from the Ringarooma River at Moorina, approximately 20 kilometres upstream of the site (Graham 1999) and also from several of its tributaries. Additionally, there are some water depth data for Rushy Lagoon (Read and Graham 2000). However, data on the hydrologic regime within the site, such as specific timing, volumes, extent of inundation and drying regime of the wetlands are not available.

Despite the lack of wetland specific data for the site, flow patterns of the lower Ringarooma River can provide clear indications of flow inputs to the Flood Plain wetlands. The seasonal flow patterns of the Ringarooma River follow the rainfall patterns, with highest flows in the winter/spring months and lowest in late summer to early autumn (Read and Graham 2000). Data in Graham (1999) from Moorina in the mid-catchment show average monthly flows of approximately 16-18 cubic metres per second from July to September, whereas February and March recorded average monthly flows of approximately two cubic metres per second (Figure 13). These data are supported by flow measures between 2002 and 2007 (Figure 14) which show distinct winter peaks, punctuated with occasional very high flow peaks, and very low flows in the February – March period. The median annual flow of the Ringarooma River at Moorina was measured as 5.9 cubic metres per second and summer median flow was 2.4 cubic metres per second (Nelson 1999).

Water levels measured at the Ringarooma River entrance to Rushy Lagoon between December 1998 and March 2000 (Figure 15) supported the rainfall patterns described above, with maximum depths occurring in the winter months, although there was a period of deeper water in January of 2000.



Figure 13: Box and whisker plots of monthly flows in the Ringarooma River at Moorina (Source: Graham 1999).



Figure 14: Instantaneous flows in the Ringarooma River at Moorina, 2002 – 2007 (Supplied by Chris Bobbi, DPIW, unpublished data).



Figure 15: Water level at the entrance of the Ringarooma River to Rushy Lagoon, Dec 1998 to March 2000 (Source: Read and Graham 2000).

As part of a study deriving an Index of River Condition for sites on the Ringarooma River, Nelson (1999) assigned a low hydrology rating to sites in the lower Ringarooma mainstream due to allocated water extraction rights being high. However, a subsequent study (Read and Graham 2000) notes that the actual volume of water taken from the Lower Ringarooma River during the lower flow months (December – April) is a small proportion of the flow in the River and therefore current water extraction rates are unlikely to impact significantly on the ecosystem of the Lower Ringarooma. Despite higher quantities of water being taken from the tributaries and the mid-reaches of the river, much of this is ultimately returned to the waterway. The water is primarily used for hydropower generation and this has negligible impact on the quality of the returned water (Bobbi, personal communication).

Read and Graham (2000) note that little is known of the ecology of the Lower Ringarooma wetlands and that informed management decisions on the ecosystems’ requirements will require comprehensive surveys of the flora and fauna. Hydrological surveys would complement these biological surveys. Many waterbirds commonly found in this area are reliant on wetting and drying cycles of wetlands for food supply and breeding habitat (Read and Graham 2000). Scott (1997) suggests that “the best scenario for managing regulated rivers and their associated wetlands is to reflect the natural patterns of flows, particularly in terms of critical parameters such as the season, duration and frequency of floods, and also periods of low flow” (Read and Graham 2000). Quantifying natural flows at the site will require flow monitoring.

The freshwater wetland complex buffers flood peaks and processes nutrients that would otherwise be deposited in the estuary. This occurs through the overbank deposition and subsequent retention of flood waters and sediments into the freshwater wetlands. It also continues to trap a portion of the mine-related sediment that will continue to be transported down the river for at least 50 years (Knighton 1991). A proportion of this sediment will continue to be transported through the estuary to the sea. In the long term, sediment trapped in the wetlands will continue to change the form and location of the flooded area (Jerie and Houshold 2001), and so has the potential to impact on the ecological character of the site (Jerie, personal communication).

1.5.5Water Quality


Similar to hydrology, there are little water quality data from within the site for either the wetland habitats or river. However, water quality data are available from the Ringarooma River, upstream of the site, at Gladstone (Bobbi 1999), providing some information on the quality of water that enters the wetlands from the river. Note that the comparison of the Ringarooma River water quality against trigger values (below) is provided to give a general understanding of the quality of water that enters the site. From the perspective of an ECD, the quality of the water at the time of listing is the baseline water quality, not the trigger values provided in Table 5.

Table 5 shows the data compared against default trigger values from the ANZECC and ARMCANZ (2000) Guidelines for Marine and Freshwaters, which were published after the 1999 report by Bobbi (1999). The ANZECC default trigger values are set at a broad scale, ranging from south-east Queensland to Tasmania and cannot be applied to all rivers within the region. The ANZECC guidelines document states a clear preference for locally derived trigger values over the default values, as the default values are generalised for large regions. Bobbi (1999) provided locally derived trigger values for turbidity and electrical conductivity, and these should be considered in preference to the ANZECC trigger values.

The data from the Ringarooma River at Gladstone is indicative of high quality waters for a lowland river in south-eastern Australia (Table 5). Although several of the data points in Table 5 were read from graphs and therefore may not be precise, the nature of the water quality is evident regardless of this imprecision. The water is high quality for an aquatic ecosystem with low electrical conductivity (an indicator of salinity) and turbidity (‘muddiness’), and high dissolved oxygen concentrations.

Table 5: Median Water Quality Data and relevant indicative guidelines for the Ringarooma River at Gladstone.



Water Quality Indicator

Trigger Value§

Median reading from the Ringarooma River at Gladstone‡

pH

6.5 – 8.0

6.6

Turbidity (NTU)

(6 – 50) 12*

6

Dissolved Oxygen

85 - 100%

9.5 mg/L

Electrical Conductivity (μS/cm)

(125 – 2200) 500*

75

Total Phosphorus μg/L

50

12

Total Nitrogen μg/L

500

583

§ANZECC, ARMCANZ 2000 default Trigger values for Lowland Rivers in SE Australia.

*Value derived from professional judgement.

‡ Median from 12 samples taken between January and December 1988 (Bobbi 1999).

The ANZECC guideline value for dissolved oxygen was presented as percent saturation but measured in mg/L in Bobbi (1999). A median concentration of 9.5 milligrams per litre is indicative of well aerated waters and for the temperatures encountered at the site is likely to be within the 90 percent saturation guideline. Phosphorus and nitrogen are typically the two major nutrients associated with excessive growths of algae and other water plants. Phosphorus concentrations are well below the ANZECC default trigger values, whereas nitrogen concentrations slightly exceed the default. In combination, the water quality indicators show that the water delivered from the Ringarooma River to the site is high quality.


1.5.6Vegetation


Vegetation can be described and classified in a number of ways, including the use of species lists, structure, communities/species associations, or a combination of these. A classification for mapping vegetation communities in Tasmania was developed by DPIW and is available online (refer DPIW 2008b). This classification was used by DPIW (2006) in a survey of a large part of the site (Figure 16). Plant communities and their corresponding Ramsar Wetland Type found onsite are described in Table 6. Not all wetland types were covered by DPIW (2006).

Table 6: Plant communities identified & their corresponding Ramsar Wetland Types.



DPIPWE Classification

Ramsar Wetland Types

Coast paperbark swamp forest

Type Xf: Freshwater, tree-dominated wetlands

Blackwood swamp forest

Type Xf: Freshwater, tree-dominated wetlands (listed as Xfa in Figure 10)

Scented paperbark scrub

Type W: Shrub-dominated wetlands

Freshwater aquatic herbland

Type Tp: Permanent freshwater marshes/pools; ponds (below 8 ha), marshes and swamps on inorganic soils; with emergent vegetation water-logged for at least most of the growing season

Freshwater aquatic rushland & sedgeland

Type Ts: Seasonal/intermittent freshwater marshes/pools on inorganic soils

Lacustrine herbland

Type Ts: Seasonal/intermittent freshwater marshes/pools on inorganic soils

Lowland grassy sedgeland

Type Ts: Seasonal/intermittent freshwater marshes/pools on inorganic soils

Coastal heathland

Type W: Shrub-dominated wetlands; shrub swamps, shrub-dominated freshwater marshes, shrub carr, alder thicket on inorganic soils

Lowland sedgy heathland

Type W: Shrub-dominated wetlands; shrub swamps, shrub-dominated freshwater marshes, shrub carr, alder thicket on inorganic soils

Wet heathland

Type W: Shrub-dominated wetlands; shrub swamps, shrub-dominated freshwater marshes, shrub carr, alder thicket on inorganic soils

Black peppermint coastal forest & woodland

Not wetland

The key species associated with each plant community is presented in Appendix 2.

Coast paperbark swamp forest native vegetation community is listed as threatened under the NCA 2002. The freshwater aquatic herbland, lacustrine herbland and lowland grassy sedgeland are all within the ‘wetland’ category and this entire category is also classified threatened (NCA 2002).

The swamp forests (coast paperbark and blackwood) both require poorly drained or intermittently inundated land for survival (DPIW 2006) and a key issue for management of these forests is the maintenance of adequate water inputs.

Coast paperbark swamp forest tends to occupy a zone that is poorly drained and sometimes waterlogged, whereas blackwood (Acacia melanoxylon) swamp forest occurs on wetter areas such as the alluvial flats that are generally inundated or very poorly drained. Within the site the blackwood swamp forest shows an association with the Ringarooma River and some of the smaller drainage channels that meander through the area. Although blackwood is the dominant tree in the blackwood swamp forest, coast paperbark also occurs and its abundance is probably associated with the level of flood disturbance that occurs at the site, the more disturbance, the more coast paperbark (DPIW 2006).


Figure 16: Vegetation Survey of part of the Flood Plain Lower Ringarooma Ramsar Site (DPIW 2006). Mapping units used are from TASVEG (Harris and Kitchener 2005.

DPIW (2006) notes that, “the size, shape and species composition of the wetlands is largely related to the amount of water present and the length of time for which water is present each year. Changes in water availability would have a direct impact on the wetland environments”. Permanent or semi-permanent inundation is required for the freshwater aquatic herbland and the freshwater aquatic sedgeland and rushland. The lacustrine herbland is essentially an ecotone between the aquatic wetlands and the drier communities. DPIW (2006) note that the most extensive lacustrine herbland observed occurs on the western edge of Shantys Lagoon. This community is relatively diverse and includes species of sedge, herb and rush.

In addition to the rare or threatened plant communities, threatened flora species known to occur on the site include one terrestrial species shiny grasstree, (Xanthorrea bracteata) (vulnerable, TSPA, in the coastal heathland) and four wetland dependent species:



  • purple loosestrife (vulnerable, TSPA), found in the more open areas of the coastal paperbark swamp forest, and also in the wetland communities (Freshwater aquatic herbland, lacustrine herbland and lowland grassy sedgeland);

  • ribbon weed (rare, TSPA), in the freshwater aquatic herbland community;

  • native gypsywort (endangered, TSPA), found in the lacustrine herbland communities; and

  • erect marshflower (rare, TSPA), which wasn’t recorded by DPIW (2006) but is reported elsewhere (DPIW, undated b) as occurring in The Chimneys and being found in stationary to slow-flowing water to a depth of 50 centimetres.

The DPIW survey was not conducted across the entire site. Other vegetation communities recorded as occurring on the site (RIS 2005) include:

  • saltmarsh

  • coastal grass and herbfield

  • coastal scrub

  • Acacia longifolia coastal scrub

  • Allocasuarina verticillata forest

While these are not mapped they all occur in the estuarine or coastal zones.

A number of species found on the flood plain are of botanical interest, including Persicaria praetermissa (located at less than 20 sites in the State); Centipeda elatinoides; and the Isolepis fluitans aquatic community at the site, which are all poorly reserved in Tasmania (RIS 2005).

Within Tasmania, saltmarsh vegetation communities which occur on the site qualify for two of the Biodiversity Criteria developed by the National Forest Policy Statement Implementation Sub-committee [a joint committee of ANZECC] and MCFFA. These criteria are:


  • Criterion (one); as less than three percent of the pre-1750 distribution of saltmarsh vegetation is protected in the Comprehensive Adequate and Representative (CAR) reserve system and

  • Criterion (five); as they are a habitat for migratory species which are also often rare, vulnerable or endangered.

Although saltmarsh communities are not currently listed as threatened within Tasmania, these communities serve a critical ecological function and are at risk due to their low reservation status (RIS 2005).

1.5.7Fauna


Although data on faunal presence, abundance and distribution are limited for the site, there is some useful information available including site records on the DPIW Natural Values Atlas. This includes a list of bird species for part of the site (Appendix 3), species listed under international agreements and a list of rare and threatened species at State and Commonwealth level (refer Section 2.2). Additionally, the DPIW (2006) vegetation survey noted habitat types that may be utilised by threatened species that had been recorded, or are likely to be present, at the site (Table 7). Table 7 presents the species and their habitat (as described by DPIW vegetation community), as well as the relevant Ramsar wetland type (in parentheses).

Table 7: Identified habitat types for threatened species and migratory birds.



Fauna species & notes

Habitat

Tasmanian spotted-tailed quoll (Dasyurus maculatus maculatus)(vulnerable, EPBC)

  • Almost certain to be present.

  • Known from private land west of the site.

  • Blackwood swamp forest: potential habitat is widespread in this community within the site (Xf)

  • Coastal heathland: potential habitat is widespread in this community within the site (W)

  • Black peppermint coastal forest: potential habitat is widespread in this community within the site

Grey goshawk (Accipiter novaehollandiae) (Endangered TPSA)

  • Blackwood swamp forest: potential nesting habitat (Xf)

  • Coast paperbark swamp forest: potential nesting habitat where the community contains blackwoods (Xf)

Dwarf galaxias (Galaxiella pusilla) (vulnerable, EPBC)

  • Known to be associated with wetland habitat types at the site.

  • species range declining due to wetland drainage.

  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

Tasmanian mudfish (Neochanna cleaveri) (not listed as threatened)

  • species range declining due to wetland drainage.

  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

Tasmanian whitebait (Lovettia seali) (not listed as threatened)

  • species range declining due to wetland drainage.

  • Estuarine waters (F)

Australian grayling (Prototroctes maraena)(vulnerable, EPBC)

  • Estuarine waters (F)

  • Permanent rivers, streams & creeks (M)

Green and gold frog (Litoria raniformis) (vulnerable, EPBC)

  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

Cattle egret (Ardea ibis)

Great egret (Ardea modesta)

Black-fronted dotterel (Elseyornis melanops)


  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

  • Non-forested peatlands (U)

  • Seasonal intermittent lakes (P)

Latham’s snipe (Gallinago hardwickii)

Australasian shoveler (Anas rhynchotis)



  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

Curlew sandpiper (Calidris ferruginea)
Red-necked stint (Calidris ruficollis)
Caspian tern (Hydroprogne caspia)
Greenshank (Tringa nebularia)
Red-capped plover (Charadrius ruficapillus).

  • Freshwater aquatic herbland (Tp)

  • Freshwater aquatic rushland and sedgeland (Ts)

  • Lacustrine herbland (Ts)

  • Non-forested peatlands (U)

  • Seasonal intermittent lakes (P)

  • Estuarine waters (F)

  • Sand, shingle or pebble shores; includes sand bars, spits and sandy islets; includes dune systems and humid dune slacks (E)

  • Coastal brackish/saline lagoons; brackish to saline lagoons with at least one relatively narrow connection to the sea (J)

  • Intertidal mud, sand or salt flats (G)

  • Intertidal marshes; includes salt marshes, salt meadows, saltings, raised salt marshes; includes tidal brackish and freshwater marshes (H)

Bar-tailed godwit (Limosa lapponica)
Ruddy turnstone (Arenaria interpres)
Little tern (Sterna albifrons, rare, TSPA)
Fairy tern (Sterna nereis, rare, TSPA)
Hooded plover (Thinornis rubricollis)

  • Estuarine waters (F)

  • Sand, shingle or pebble shores; includes sand bars, spits and sandy islets; includes dune systems and humid dune slacks (E)

  • Coastal brackish/saline lagoons; brackish to saline lagoons with at least one relatively narrow connection to the sea (J)

  • Intertidal mud, sand or salt flats (G)

  • Intertidal marshes; includes salt marshes, salt meadows, saltings, raised salt marshes; includes tidal brackish and freshwater marshes (H)

Tasmanian wedge-tailed eagle (Aquila audax fleayi, Endangered, EPBC and endangered, TSPA)

  • All habitat except closed forest

White-bellied sea eagle (Haliaeetus leucogaster, vulnerable, TSPA).

  • Estuarine waters (F)

  • Permanent rivers, streams & creeks (M)

  • Seasonal intermittent lakes (P).

Eleven migratory bird species listed in CAMBA, JAMBA, ROKAMBA and/or CMS are:

  • cattle egret

  • great egret

  • white-bellied sea-eagle

  • Latham’s snipe

  • curlew sandpiper

  • red-necked stint

  • ruddy turnstone

  • bar-tailed godwit

  • Caspian tern

  • little tern

  • greenshank

Information on these species at the site is limited to occasional sightings. However, some general information on habitat and diet for each species is provided in Table 8, below.

Table 8: Migratory bird species of the Flood Plain Ringarooma River Ramsar Site, with their common habitat and diet (Pizzey 1980; Birdlife International 2009; Birds Australia 2010; DEWHA 2010b).



Species

Habitat(s)

Diet

Cattle egret

The cattle egret inhabits a range of habitats, including open grassy areas such as meadows, livestock pastures, semi-arid steppe and open savannah grassland subject to seasonal inundation, dry arable fields, artificial grassland sites (for example lawns, parks, road margins and sports fields), flood-plains, freshwater swamps, rice-fields, wet pastures, shallow marshes, mangroves and irrigated grasslands (with ponds, small impoundments, wells, canals, small rivers and streams). It rarely occupies marine habitats or forested areas although in Australia it may enter woodlands and forests, and it shows a preference for fresh water although it may also use brackish or saline habitats. It occurs from sea-level up to approximately 1,500 metres.

Its diet consists primarily of insects such as locusts, grasshoppers, beetles, adult and larval butterflies and moths, dragonflies and centipedes. However, worms, spiders, crustaceans, frogs, tadpoles, molluscs, fish, lizards, small birds, rodents and vegetable matter may also be taken.

Great egret

The great egret inhabits many kinds of inland and coastal wetlands although it is mainly found along the coast in the winter or during droughts (for example in Australia). It frequents river margins, lakes shores, marshes, flood-plains, oxbow lakes, streams, damp meadows, aquaculture ponds, reservoirs, and the shallows of, mudflats, coastal swamps, saltmarshes, seagrass flats, offshore coral reefs, lagoons and estuaries when in coastal locations.

In aquatic habitats its diet consists of fish, amphibians, snakes, aquatic insects and crustaceans although in drier habitats terrestrial insects, lizards, small birds and mammals are more commonly taken.

White-bellied sea eagle

This species is generally found in coastal habitats, characterised by the presence of large areas of open water (larger rivers, swamps, lakes, the sea). Breeding territories are located close to water, and mainly in tall open forest or woodland

The white-bellied sea-eagle generally forages over large expanses of open water; particularly individuals that occur in coastal environments close to the sea-shore, where they forage over in-shore waters.



The white-bellied sea-eagle feeds opportunistically on a variety of fish, birds, reptiles, mammals and crustaceans, and on carrion.

Latham’s snipe

Latham's snipe are found in any vegetation around wetlands, such as sedges, grasses, reeds and rushes and also in saltmarsh and creek edges on migration. They are usually seen in small groups or singly in freshwater wetlands on or near the coast, generally among dense cover.

Latham's snipe feed at night, early morning or evening, thrusting their long bill into mud in soft mudflats or shallow water. They are omnivorous, eating seeds and plant material, worms, spiders and insects, some molluscs, isopods and centipedes.

Curlew sandpiper

The curlew sandpiper breeds in the lowlands of the high Arctic and also along the coast and islands of the Arctic Ocean. within Australia the species chiefly occurs on coastal brackish lagoons, tidal mud- and sandflats, estuaries, saltmarshes, exposed coral, rocky shores and tidewrack on sandy beaches and also inland on the muddy edges of marshes, large rivers and lakes (both saline and freshwater), irrigated land, flooded areas, dams and saltpans.

During breeding its diet consists mainly of insects, such as the adults, pupae and larva of midges, craneflies and beetles, as well as bugs and leeches. In Australia its diet is more likely to consist of invertebrates such as worms, molluscs, crustaceans and occasionally insects and seeds.


Red-necked stint

The red-necked stint is found on the coast, in sheltered inlets, bays, lagoons, estuaries, intertidal mudflats and protected sandy or coralline shores.

Red-necked stints are omnivorous, taking seeds, insects, small vertebrates, plants in saltmarshes, molluscs, gastropods and crustaceans.

Ruddy turnstone

The ruddy turnstone forages in close flocks of 10-100 or more individuals, especially in tidal areas. In Australia the species is mainly coastal, frequenting productive rocky and shingle shores, breakwaters, sandy beaches with storm-wracked seaweed, saltmarshes, sheltered inlets, estuaries, mangrove swamps, exposed reefs and mudflats with beds of molluscs.

Within its Arctic breeding grounds the species takes insects and spiders, occasionally also taking vegetable matter. In Australia its diet consists of insects, crustaceans, molluscs (especially mussels or cockles), annelids, echinoderms, small fish, carrion and birds eggs.

Bar-tailed godwit

The bar-tailed godwit breeds in, swampy areas tundra and on swampy heathlands near the Arctic treeline. In Australia it is more common in intertidal areas along muddy coastlines, estuaries, inlets, mangrove-fringed lagoons and sheltered bays with tidal mudflats or sandbars.

When breeding the species feeds on insects, worms, molluscs and occasionally seeds and berries. In Australia, in intertidal areas the species diet consists of annelid worms, bivalves and crustaceans and occasionally larval amphibians (tadpoles) and small fish. When on grasslands it will also take cranefly larvae and earthworms.

Little tern

The species breeds on barren or sparsely vegetated beaches, islands and spits on seashores or in estuaries, saltmarshes, saltpans, offshore coral reefs rivers, lakes, and reservoirs. It shows a preference for islets surrounded by saline or fresh water where small fish can be caught without the need for extensive foraging flights.

In Australia the species frequents tidal creeks, coastal lagoons and saltpans and may foraging at sea up to 15 kilometres offshore.



Its diet consists predominantly of small fish and crustaceans three and six centimetres long as well as insects, annelid worms and molluscs.

Caspian tern

The breeding, passage and wintering habitats of the Caspian tern are similar, although during the winter it is largely confined to the coast. It frequents sheltered sea coasts, estuaries, inlets, bays, harbours, coastal lagoons, and saltmarshes. When breeding the species shows a preference for nesting on sandy, shell-strewn or shingle beaches, sand-dunes, flat rock-surfaces, sheltered reefs or islands with sparse vegetation and flat or gently sloping margins surrounded by clear, shallow, undisturbed waters. It also forms winter roosts on sandbars, mudflats and banks of shell.

The Caspian tern’s diet consists predominantly of fish five and -25 centimetres in length as well as the eggs and young of other birds, carrion, aquatic invertebrates (e.g. crayfish), flying insects and earthworms.

Greenshank

In its wintering grounds the greenshank frequents a variety of freshwater, marine and artificial wetlands, including swamps, open muddy or rocky shores of lakes and large rivers, sewage farms, saltmarshes, sandy or muddy coastal flats, estuaries, lagoons and pools on tidal reefs or exposed coral, although it generally avoids open coastline. On migration (including within Australia) this species occurs on inland flooded meadows, dried-up lakes, sandbars and marshes.

This species is chiefly carnivorous, its diet consisting of insects and their larvae (especially beetles), crustaceans, annelids, molluscs, amphibians, small fish and occasionally rodents.



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