Description of Wetland Ecological Character: Yanga National Park

Description of wetland ecological character

Yanga National Park © Copyright State of NSW and the Office of Environment and Heritage, Department of Premier and Cabinet

With the exception of photographs, the Office of Environment and Heritage, Department of Premier and Cabinet (OEH) and State of NSW are pleased to allow this material to be reproduced in whole or in part for educational and non-commercial use, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs.

This publication has been compiled in good faith, exercising all due care and attention. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. OEH shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. Readers should seek appropriate advice when applying the information to their specific needs.

This project was funded by the Rivers Environmental Restoration Program which is jointly funded by the NSW Government and the Australian Government’s Water for the Future Program. It aims to arrest the decline of wetlands through water recovery, effective management of environmental water and the sustainable management of our wetlands.

The authors would like to thank the following people who contributed to this report: Paul Childs: Wetland Ecologist, OEH James Maguire: Senior Wetlands and Rivers Conservation Officer, OEH Russell Hampton, Paul McInnes and Narelle Jones: Yanga National Park, OEH Tom Davy: State Water Corporation Jennifer Spencer, Jordan Iles, Lisa Knowles and others: Rivers and Wetlands Unit, OEH

Wen L, Saintilan N and Ling J 2011. Description of wetland ecological character: Yanga National Park. Rivers and Wetlands Unit, Office of Environment and Heritage, Department of Premier and Cabinet. Sydney, Australia.

Cover photographs Main: Two Bridges Swamp – J Kelleway/OEH Right: top: Pococks Swamp, centre: River red gums at Two Bridges Swamp, bottom: Azolla at Pococks Swamp – L Wen/OEH

Published by: Office of Environment and Heritage Department of Premier and Cabinet 59–61 Goulburn Street, Sydney PO Box A290, Sydney South 1232

Report pollution and environmental incidents Environment Line: 131 555 (NSW only) or [email protected] See also www.environment.nsw.gov.au

Phone: (02) 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks, climate change and energy efficiency information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au ISBN 978 1 74293 398 6 OEH 2012/0165 Published February 2012, based on information compiled in 2009 Summary

Yanga National Park forms part of the Lowbidgee floodplain which is listed in the Directory of Important Wetlands in Australia. This description of ecological character focuses on the national park with reference to the broader Lowbidgee floodplain. It is based on the national framework and guideline for describing the ecological character of Australia’s Ramsar wetlands and has identified ecosystem benefits and services, ecological components and processes and their limits of acceptable change at its current state.

Yanga National Park meets five of the six criteria for determining nationally important wetlands. There are 12 wetland types according to Ramsar classification (10 according to Environment Australia) in the park. The dominant wetland type, river red gum (Eucalyptus camaludensis) forest/woodland, forms one of the largest stands in Australia. Other significant wetlands include Yanga Lake, Piggery Swamp and seasonal flooded lignum (Muehlenbeckia florulenta) woodland.

Approximately 17 vegetation communities have been identified in Yanga National Park ranging from river red gum riparian open forest, old man saltbush (Atriplex nummularia), lignum shrub to spike rush (Eleocharis sphacelata) swamp. Over time, 303 vascular plant species, including four endangered and one vulnerable, have been recorded within these communities. The diverse ranges of vegetation provide habitats for various animals. There are 269 fauna species (excluding fish) which have been recorded in the site, including 25 mammals, 24 reptiles, 11 amphibians and 210 birds.

Yanga National Park supports the populations of a number of internationally and nationally threatened species included in the global ‘red list’ of the International Union for Conservation or listed under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. There is a total of 21 endangered and vulnerable species, 12 of which are waterbirds, which have been recorded in Yanga National Park, such as Australasian bittern (Botaurus poiciloptilus), freckled duck (Stictonetta naevosa) and blue-billed duck (Oxyura australis). The southern bell frog (Litoria raniformis), which is considered to be endangered at state level, has been recorded in Piggery Swamp, Mercedes Swamp and Twin-bridge Swamp.

There are 61 species of waterbirds observed using the site as roosting, feeding and nesting/breeding habitat. Important areas include Tarwillie Swamp, Shaw’s Swamp, Piggery Lake, Two-Bridge Swamp located between Redbank Weir and Lambing Down Hill, and river red gum forests within 10 km of Redbank Weir along the Murrumbidgee River.

The site also supports a broad range of recreational, educational and scientific activities, and has a high social and cultural value. The site has become a major national focus for floodplain ecological research activities since 2007 when it was gazetted as a national park. Substantial levels of scientific study and investigation have been undertaken in the park, particularly relating to natural heritage values. Sites of Aboriginal and European heritage are also found within the area.

Currently, the site is highly stressed as evidenced by large scale degradation of vegetation condition, sharp decrease in the abundance of waterbirds, and wide dispersion of the exotic European carp. Hydrological alteration due to upstream water division and fragmentation caused by engineering works within the floodplain are identified as the major threatens. The geological setting of the site means that environmental water provision is the most practical method for recovering and maintaining the ecological character of the site.

There are a number of knowledge gaps and monitoring requirements regarding the important components and critical processes of the site which limit the current capacity to establish benchmarks, detect changes and set ‘limits of acceptable change’ for ecological character. Flow path and inundation pattern, extent of aquatic vegetation communities, number of waterbird species and abundance, and condition of river red gum forest are given high priorities.

Management (D) Climate (D) Geomorphology (D) Human disturbance (D) EWAs Rainfall Fractures and faults River regulation Re-snagging Temperature Surface geology (bedrock Water diversion Dam removal Evaporation & soil types) Drainage network Levee breach Wind Topography Infrastructure Weed and pest control Solar radiation Aquifers Grazing Erosion control Extreme events Clearing Burning Hydrogeologic Settings (D) Agricultural runoff

Hydrological regimes (C) Wetland Frequency, duration and depth of inundation Ecosystem Groundwater recharge/discharge Dry-wet cycles

Soil (sediment) Chemistry Physical forms (C/P) Water Chemistry (C/P) (C/P) Erosion Salinity N, P, Ca, Si etc availability Sedimentation Nutrients Nutrient cycle Wetland size and distribution Turbidity Carbon cycle Habitat availability Water quality Soil type and distribution Habitat connectivity

Primary Production and Trophic Structure (C)

Decomposers Producers (C) Primary / secondary (C) Tertiary consumers (C) (C) Phytoplankton consumers Reptile and mammals Fungi Periphyton Zooplankton Fish Vegetation Macroinvertebrates Land bird and Waterbird Bacteria Invertebrates Amphibians

Services and Benefits Biodiversity conservation: unique wetland types, diverse habitats, ecological communities, drought refuge Nature observation: education and scientific research Recreation and tourism Cultural

The overall ecological conceptual model developed for the description of ecological character of Yanga National Park. Feedback from biota to their environment and interactions among biological communities were omitted for simplicity. D, Driver; C, Component; P, Process. 8r

D qpv 1.1 Brief description of Yanga National Park ...... 1 1.2 Objectives of description of ecological character...... 3 1.3 Concepts applied and approaches for description of ecological character...... 3 1.3.1 Ecological character...... 3 1.3.2 Approaches taken in a description of ecological character ...... 5 1.4 Policy framework...... 6 ! Pr vrs`hthIhvhyQh x ( 2.1 Site location and its catchment ...... 9 2.1.1 Site location and boundary...... 9 2.1.2 Murrumbidgee catchment ...... 9 2.2 Climate...... 12 2.3 Geology...... 14 2.4 Landform...... 15 2.5 Land tenure...... 15 2.5.1 Land use before dedication as a national park ...... 15 2.6 Wetland types within Yanga National Park ...... 19 2.7 Ecosystem services ...... 19 " Pr hyypprhyrpytvphyqry ! # @pytvphyr vprhqirrsv !" 4.1 Regulating services...... 23 4.1.1 Maintaining regional water quality...... 23 4.1.2 Replenish groundwater ...... 23 4.1.3 Flood control ...... 25 4.1.4 Regulate climate ...... 25 4.2 Supporting services ...... 26 4.2.1 Provides a combination of wetland types, which is typical in the NSW Riverina Bioregion ...... 26 4.2.2 Supports biota species that maintain biodiversity of the NSW Riverina Bioregion...... 26 4.2.3 Supports two endangered ecological communities...... 27 4.2.4 Supports 21 threatened fauna species ...... 29 4.2.5 Supports four endangered and vulnerable plant species...... 29 4.2.6 Supports at least one threatened fish species ...... 31 4.2.7 Supports an abundance of waterbirds ...... 31 4.2.8 Supports eleven migratory species covered in migratory bird agreements ...... 34 4.2.9 Supports large stands of primary producers ...... 34 4.2.10 Provides important feeding, spawning and nursing grounds for native fish ...... 35 4.3 Cultural services ...... 36 4.3.1 Aboriginal heritage ...... 36 4.3.2 European heritage...... 36 4.3.3 Scientific research...... 36 5 Description of specified components that support selected ecosystem services...... 37 5.1 Physical components of Yanga National Park ...... 37 5.1.1 Important wetlands...... 37 5.1.2 Large woody debris...... 45 5.1.3 Fire ...... 46 5.2 Chemical components ...... 46 5.2.1 Soil chemistry...... 46 5.2.2 Water quality ...... 47 5.3 Biological component of Yanga National Park...... 50 5.3.1 Important plant communities ...... 50 5.3.2 Waterbirds...... 57 5.3.3 Fish ...... 60 5.3.4 Frogs ...... 60 5.3.5 Reptiles ...... 62 5.3.6 Mammals...... 62 6 Critical ecosystem processes ...... 65 6.1 Hydrological processes...... 65 6.1.1 Natural overbank flows...... 65 6.1.2 Artificial Watering ...... 70 6.2 Geomorphologic processes ...... 71 6.2.1 Sedimentation ...... 71 6.3 Nutrient cycling and trophic dynamics...... 74 7 Limits of acceptable change to key ecological components ...... 75 8 Actual and likely threats to the ecological character of Yanga National Park.. 80 8.1 Alteration to the natural flow regimes...... 80 8.2 Habitat loss and fragmentation ...... 81 8.3 Introduced and problematic species ...... 85 8.4 Climate change ...... 85 8.4.1 Higher temperatures ...... 86 8.4.2 Changes to rainfall patterns and intensity ...... 86 8.5 Other issues...... 86 9 Knowledge gaps ...... 88 10 Recommended monitoring program...... 90 10.1 Monitoring objectives ...... 90 10.2 Recommended monitoring framework ...... 90 11 Communication, education and public awareness messages...... 94 11.1 Major CEPA activities for Yanga National Park ...... 94 11.2 Important CEPA messages...... 95 Appendix 1 Plant species in Yanga National Park ...... 96 Appendix 2 Bird species in Yanga National Park...... 103 References ...... 108 Tables Table 1: Details of the description of wetland ecological character of Yanga National Park ...... 2 Table 2: Major land use in the Murrumbidgee catchment...... 11 Table 3: Description of soil landscapes in Yanga Nation Park...... 15 Table 4: Detailed land use in Yanga National Park before purchase by DEC ...... 17 Table 5: Wetland types found within Yanga National Park in order of dominance ..... 20 Table 6: Ecosystem benefits and services...... 24 Table 7: Fauna and flora records in Yanga National Park and the NSW Riverina Bioregion...... 27 Table 8: Endangered and vulnerable fauna found within Yanga National Park...... 30 Table 9: Endangered and vulnerable plant species found in Yanga National Park .... 30 Table 10: Waterbird species of national, state and regional importance recorded in the 1989–90 survey in Yanga National Park...... 32 Table 11: Migratory birds protected under international treaties...... 34 Table 12: Ecosystem components of Yanga National Park...... 38 Table 13: Important wetlands within Yanga National Park...... 40 Table 14: Soil chemistry characteristics in Yanga National Park, average values for a 1-m soil profile...... 47 Table 15: Plant communities found within Yanga National Park...... 52 Table 16: Major bird surveys in Lowbidgee region which have sites in Yanga National Park ...... 58 Table 17: Waterbird species recorded in Yanga National Park and surrounding floodplains...... 58 Table 18: Fish species in the Lowbidgee region, including the Murrumbidgee channel ...... 61 Table 19: Frog species in Yanga National Park and surrounding floodplains...... 62 Table 20: Reptiles recorded in Yanga National Park and surrounding floodplains...... 63 Table 21: Mammal species in Yanga National Park and surroundings...... 64 Table 22: Hydrological processes in Yanga National Park ...... 66 Table 23: Major developments on the Murrumbidgee River 1855–1982 ...... 68 Table 24: Changes in selected hydrological indicators in the Murrumbidgee downstream of Redbank Weir...... 69 Table 25: Limits of acceptable change for critical components and processes of Yanga National Park ...... 76 Table 26: Summary of actual and likely threats to the ecological character of the Lowbidgee floodplain ...... 82 Table 27: Key knowledge gaps and recommended monitoring and actions...... 89 Table 28: Recommended monitoring program for Yanga National Park ...... 91 Figures Figure 1: Relationship of the ecological character description to other documents ...... 4 Figure 2: Relationships among ecological components, processes and services that comprise the ecological character of a wetland ecosystem...... 4 Figure 3: Yanga National Park and the main waterways ...... 10 Figure 4: The Murrumbidgee catchment and main land use...... 11 Figure 5: Monthly rainfall distribution at Balranald, average for 119 years from 1889 to 2006 ...... 12 Figure 6: Mean monthly radiation and evaporation at Balranald, average of 118 years from 1889 to 2006 ...... 13 Figure 7: Mean maximum and minimum temperatures at Balranald, average for 118 years from 1889 to 2006 ...... 13 Figure 8: Soil landscape in Lowbidgee ...... 16 Figure 9: Land use in Yanga National Park before dedication as a national park...... 18 Figure 10: Overall ecological conceptual model for Yanga National Park ...... 22 Figure 11: Schematic of the conceptual model for groundwater, illustrating the major recharge areas in the floodplain...... 24 Figure 12: The effect of wetlands on peak stormwater flows ...... 25 Figure 13: Twin-bridges Swamp, a freshwater wetland in Yanga National Park, which accommodates the threatened aquatic ecological community including the southern bell frog ...... 28 Figure 14: Important waterbird feeding and breeding sites in Yanga National Park identified during the 1989–90 survey ...... 33 Figure 15: Floodplain wetlands as fish feeding, spawning and nursery habitat ...... 35 Figure 16: Yanga homestead...... 36 Figure 17: Locations of the 23 wetlands listed in Table 13 ...... 39 Figure 18: The early development of saltbush at Yanga Lake in 2007 ...... 43 Figure 19: Tala Lake in 2007, showing dead river red gums caused by permanent inundation before it dried out in 2001...... 43 Figure 20: Piggery Lake when inundated and dry...... 44 Figure 21: Two Bridges swamp before (left) and after (right) receiving environmental water allocation...... 44 Figure 22: Mercedes Swamp before (left) and after (right) receiving environmental water allocation ...... 44 Figure 23: Piles of river red gum branches which provide habitat for amphibians, reptiles, birds and small mammals...... 45 Figure 24: A fallen tree in the Murrumbidgee River channel downstream from Redbank Weir providing a surface for algae, microscopic plants and animals ...... 46 Figure 25: Soil sampling sites at Yanga National Park ...... 48 Figure 26: Vegetation distribution in Yanga National Park...... 51 Figure 27: Condition of river red gums in 2005 based on aerial photography...... 55 Figure 28: Lignum swamp at the Fingerboards in Lowbidgee with black box in the background ...... 56 Figure 29: Lignum swamps, which provide important waterbird breeding habitat in the Lowbidgee floodplain ...... 56 Figure 30: Relationships between hydrological cycle and other floodplain ecological processes under a natural flood regime...... 67 Figure 31: Monthly flow distribution before and after 1970 ...... 69 Figure 32: Irrigation water distribution pattern in Yanga National Park...... 70 Figure 33: Water diverted to Yanga National Park from the Murrumbidgee River ...... 71 Figure 34: Sediment erosion and deposition processes in the river–floodplain system. 73 Figure 35: The three geomorphic regions of the Murrumbidgee catchment ...... 73 Figure 36: Limits of acceptable change ...... 75 Figure 37: Conceptual ecological model of risks in Yanga National Park...... 84 Figure 38: Linkages between climate change and ecosystem responses ...... 86

Abbreviations CAMBA China–Australia Migratory Bird Agreement CEPA communication, education and public awareness DECC Department of Environment and Conservation NSW DLWC Department of Land and Water Conservation NSW DO dissolved oxygen EEC endangered ecological community EPBC Act Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) ESP exchangeable sodium percentage EWA environmental water allocation FCID Flood Control and Irrigation District JAMBA Japan–Australia Migratory Bird Agreement MEA Millennium Ecosystem Assessment MIA Murrumbidgee Irrigation Area NPW Act National Parks and Wildlife Act 1974 (NSW) NPWS NSW National Parks and Wildlife Service OEH Office of Environment and Heritage, Department of Premier and Cabinet RERP Rivers Environmental Restoration Program ROKAMBA Republic of Korea – Australia Migratory Bird Agreement TP Total phosphorus TSC Act Threatened Species Conservation Act 1995 (NSW)

1 Introduction

This project seeks to define the ecological character of wetlands on the lower Murrumbidgee (Lowbidgee) floodplain with the focus on the newly designated Yanga National Park. The sustainable management of the region’s wetlands is contingent upon a sound understanding of the key ecological components, the processes which sustain those values, and the natural variability primarily driven by a variable hydrological regime. Detailed knowledge is essential to understand a wetland’s water requirement and how a wetland will response to water management change, and thus can greatly enhance the ability to manage environmental water allocations (EWAs). The report also identifies the actual and potential threats to the existence and integrity of a region’s wetlands and identifies and recommends indicators for monitoring change in ecological character. The report developed for the region should also identify management actions that could be incorporated within management plans.

This report was compiled by the Department of Environment and Climate Change NSW, now the Office of Environment and Heritage (OEH), following the Australian national framework and guideline for describing the ecological character of Ramsar wetlands (DEWHA 2008). While this report is not an ecological character description (ECD) within the Ramsar context, the Commonwealth guidelines for Ramsar wetlands provides a sound basis for a literature review, recognition of key ecological assets, definition of natural variability, and identification of key indicators of change and knowledge gaps. Although the Lowbidgee area doesn’t contain Ramsar sites, wetlands of regional, state, and national importance are widespread (Pressey et al. 1984; Maher 1990; Kingsford and Thomas 2001).

The project is a component of the NSW Rivers Environmental Restoration Program (RERP) subprogram, Better use of environmental water. This subprogram is a joint NSW and Commonwealth Government initiative aimed at maximising the environmental benefit for the investment of water through market based water recovery. The Lowbidgee floodplain has been identified as one of a limited number of sites within this program where detailed ecological investigations will contribute to the efficient and targeted delivery of environmental water. The overall objective of this wetland description of the Lowbidgee is to review and systematise available information in support of the sustainable management of the key wetland sites.

1.1 Brief description of Yanga National Park

Yanga National Park is part of the Lowbidgee floodplain. Recognised for its regional ecological values and conservation importance, the site was purchased by the NSW Government in 2005, and Yanga National Park was gazetted in February 2007. The newly created national park also includes Yanga Nature Reserve (1932 ha) created in 1974 under the National Parks and Wildlife Act 1974 (NSW) (NPW Act).

The Lowbidgee floodplain is renowned for its wetlands as critical fish and waterbird habitats and refuge for biodiversity in arid and semi-arid Australia (Maher 1990; Kingsford and Thomas 2001; Watts et al. 2001; Gilligan 2005). In their natural state, many of the wetlands in the region are characterised by variable and unpredictable patterns of high and low flows and water levels. The natural morphology of the river system includes deep channels, deep pool areas, sandy–muddy banks, terraces formed by floods, suspended load depositional ‘benches’, higher floodplain benches, paleochannels, flood runners, anabranches, billabongs and lakes. The complex river– floodplain morphology provides an array of habitats that play a critical role in the life cycles of the many fish and waterbird species. Over the last 50–100 years the wetlands on the Lowbidgee floodplain have changed significantly from their natural state. The

Yanga National Park 1 ecosystem is experiencing degradation due to instream regulation structures (e.g. dams and weirs), upstream water diversions, flood prevention structures (e.g. levees), deterioration of water quality, clearing of riparian vegetation and grazing, and the presence of exotic species (Pressey et al. 1984; Maher 1990; Hillman et al. 2000; Kingsford and Thomas 2001; Frazier and Page 2006; Wen et al. 2009).

Table 1 provides basic information about the site regarding the preparation of the description of wetland ecological character.

Table 1: Details of the description of wetland ecological character of Yanga National Park

Site name Yanga National Park Yanga National Park is located in the floodplain of the lower reach of the Murrumbidgee River between Maude and Location Balranald Weir, approximately 110 kilometres west of Hay, inland NSW. Area 66,734 ha, includes 1932 ha of Yanga Nature Reserve Geographic coordinates 34° 39’S, 143° 35’E Altitude 0–70m ASL Date of listing as a Ramsar Not listed. site Year of listing as national 1991 important wetland Date for which the description February 2009 of ecological character applies Office of Environment and Heritage Management authorities Department of Premier and Cabinet This is the first description of the ecological character of Status of description Yanga National Park. Wen L, Ling JE and Saintilan N Rivers and Wetlands Unit Name of compiler Water and Catchments Science Division Office of Environment and Heritage Department of Premier and Cabinet Date of compilation February 2009 A Directory of Important Wetlands in Australia: Reference for Information Lowbidgee Floodplain Wetland Sheet Department of Environment and Water Resources, http://deh.gov.au/water/wetlands/database/index.html Reference for management OEH is developing a plan of management. plan

2 Description of wetland ecological character 1.2 Objectives of description of ecological character

Investigating, understanding and documenting ecological character is the cornerstone to maintaining and protecting the values of wetland ecosystems. The description of ecological character underpins the development of a wetland management plan by providing baseline information about the components and processes, services and benefits, risks and threats of the site. It also identifies the key knowledge gaps and helps the development of a monitoring, evaluation and reporting framework. Figure 1 shows the relationships between the description of ecological character and other planning and management processes and documents. The wetland ecological description will form the reference for: development (or update) and implementation of an environmental management plan designed to maintain the ecological character of the region development (or update) and implementation of monitoring programs to detect changes in ecological character assessment of the effectiveness of management actions, especially environmental water allocation regular evaluation of the results of monitoring programs to assist adaptive management.

This description of ecological character contributed to the RERP subprogram Better use of environmental water through enhancing the knowledge of water requirements to maintain the ecological character of wetlands within Lowbidgee, particularly in Yanga National Park, in terms of: identifying and describing key ecological assets and their values and services identifying key ecological components and critical ecological processes that sustain these ecological values providing conceptual models describing relationships between processes and populations of plants and animals – resident and itinerant identifying key actual and potential threats to the site identifying key knowledge gaps and making recommendations for key monitoring needs benchmarking and tracking changes in ecological character in recent decades.

1.3 Concepts applied and approaches for description of ecological character The main concepts in this description of ecological character were adapted from the Ramsar Convention and its associated documents such as the Millennium Ecosystem Assessment report to the Ramsar Convention (MEA 2005). The steps taken to describe the ecological character are adapted from those outlined in the National framework and guideance for describing the ecological character of Australian Ramsar wetlands (DEWHA 2008).

1.3.1 Ecological character Wetlands are by their very nature both productive and dynamic systems, and the Ramsar Convention definition of ecological character as ‘the combination of the ecosystem components, processes and benefits/services that characterise the wetland at a given point in time’ (Ramsar Convention 2005, Resolution IX.1 Annex A) acknowledges these attributes. The definition emphasises the links between the ecological components, their processes or interactions and the benefits or services they support (Figure 2).

Other key definitions of associated terms are outlined below.

Yanga National Park 3 Wetland Information Sheet EPBC Act Regulatory Role e.g. Compliance action under the EPBC Act Ecological Character Description Framework and Guidance for ECD (ECD)

Monitoring Natural Resource Environment Condition reporting Management and Management Plan Planning Communication and Other land use planning Environmental Water awareness raising (e.g. Local Government) Management Plan

Research

Environmental Impact Assessment

Source: modified from Lambert and Elix (2006)

Figure 1: Relationship of the ecological character description to other documents

System Drivers Component and Services and Benefits Processes • Climate • Provisioning • Vegetation community o Rainfall o Fishery • Phytoplankton o Evaporation o Timber • Birds o Temperature • Fish o Solar radiation • Regulating • Reptile, amphibian and o Wind o Water quality mammals o Extreme weather o Flood control • Invertebrates • Hydrogeomorphology o Local climate • Water chemistry o Topography • Soil chemistry o Soil • Supporting o Aquifer o Biodiversity o Hydrology • Salinity, DO & pH o Naturalness • Management fluctuations o Unique landscape o Conservation • Inundation dynamics • Natural and human • Hydrological regimes • Cultural disturbance • Sedimentation o Aboriginal heritage o Flood • Nutrient cycling o Historical sites o Fire • Primary production o Recreation and o Clearing • Biological interactions education o Recreation o Scientific studies

Ecological Character

Source: after Philips et al. (2005)

Figure 2: Relationships among ecological components, processes and services that comprise the ecological character of a wetland ecosystem

4 Description of wetland ecological character Ecosystems are described in the Millennium Ecosystem Assessment (MEA 2003) as the complex of living communities (including human communities) and non-living environment (ecosystem components) interacting (through ecological processes) as a functional unit which provides a variety of benefits to people (ecosystem services) (Ramsar Convention 2005).

Ecosystem components include the physical, chemical and biological parts of a wetland (from large scale to very small scale, e.g. habitat, species and genes) (MEA 2003, 2005; Resolution IX.1 Annex A).

Ecosystem processes are the dynamic forces within an ecosystem. They include all those processes that occur between organisms and within and between populations and communities, including interactions with the non-living environment, which result in existing ecosystems and bring about changes in ecosystems over time (Australian Heritage Commission 2002). They may be physical, chemical or biological (Ramsar Convention 1996, Resolution VI.1 Annex A).

Benefits/services are defined in accordance with the Millennium Ecosystem Assessment definition of ecosystem services as ‘the benefits that people receive from ecosystems’ (MEA 2005; Ramsar Convention 2005, Resolution IX.1 Annex A). However, in the context of the Ramsar Convention this term also refers to products, functions, and attributes as defined in Ramsar Resolution VI.1 and includes both material and non-material cultural values, benefits and functions as outlined in CoP8 DOC.15: Cultural aspects of wetlands (Ramsar Convention 2005, Resolution IX.1 Annex A).

Change in ecological character is defined as the human-induced adverse alteration of any ecosystem component, process, and/or ecosystem benefit/service (Ramsar Convention 2005, Resolution IX.1 Annex A).

1.3.2 Approaches taken in a description of ecological character

The Ramsar Convention has defined ecological character and change in ecological character, and provided frameworks and guidelines for management planning, establishing monitoring programs and undertaking risk assessments. However, definitive guidance on how to describe ecological character has not been forthcoming from the Convention to date despite recognition that it is needed.

The main steps in writing this report (DEWHA 2008) were as follows. 1 Prepare an introduction to the description: site details, purpose of the description, relevant legislation, and methods. 2 Describe the site: location, climate, maps and images, tenure, wetland criteria and types. 3 Identify and describe the critical components, processes and services. 4 Develop a conceptual model for the wetland: depict the critical components and processes of the wetland and their relationships. 5 Set limits of acceptable change: determine limits of acceptable change for critical components, processes and services of the site. 6 Identify threats to the ecological character of the site using information from steps 3–5. 7 Describe changes to ecological character if appropriate. This step refers to changes in ecological character since the time of listing of a site as a Ramsar

Yanga National Park 5 wetland. As this is not relevant in the case of the lower Lachlan River, a summary of documented changes in ecological character is provided instead. 8 Summarise the knowledge gaps using information from steps 3–7. 9 Identify site monitoring needs. 10 Identify communication and education messages. 11 Compile the ecological character description. 12 Prepare or update the Ramsar Information Sheet (not applicable).

1.4 Policy framework

There are numerous treaties, national and state legislation and regulations that are relevant, and these include the following.

International treaties

Japan–Australia Migratory Bird Agreement (JAMBA, 1974) is a bilateral agreement between the Australian Government and the Government of Japan that requires both parties to protect and conserve habitats important to the conservation of migratory birds and to cooperate with regards to the protection of threatened birds.

China–Australia Migratory Bird Agreement (CAMBA, 1986) is a bilateral agreement between the Australian Government and the People’s Republic of China that requires both parties to protect and conserve habitats important to the conservation of migratory birds.

Republic of Korea – Australia Migratory Bird Agreement (ROKAMBA) is a bilateral agreement between the Australian Government and the Republic of Korea commencing in 2007 that requires both parties to protect and conserve migratory bird species.

Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention, 1983) is an agreement that obliges countries to cooperate to prevent any species with a distribution within their jurisdiction from becoming endangered. Australia’s obligations under this treaty mostly refer to migratory bird species.

National legislation

Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act): This is the Australian Government’s major legal framework governing the management and protection of Australia’s environment. The objectives of the EPBC Act include the protection of the environment on matters of national significance, conservation of Australian biodiversity, protection and management of significant natural and cultural places, control of movement of plants, wildlife and wildlife derived products, and promotion of ecologically sustainable development.

Australian Heritage Council Act 2003: This Act guides the actions of the Australian Heritage Council whose role is to advise the Australian Government on heritage matters and to maintain the Register of the National Estate.

Water Act 2007: This Act makes provision for the management of the water resources of the Murray–Darling Basin, to ensure that these water resources are managed in an integrated and sustainable way.and to make provision for other matters of national interest in relation to water and water information.

6 Description of wetland ecological character NSW State legislation

Aboriginal Land Rights Act 1983: This Act allows for the return to Aboriginal people of vacant crown land not required for essential or residential purposes.

Catchment Management Act 1989: This presents a framework for catchment management allowing for greater community involvement in particular.

Contaminated Land Management Act 1997: This Act legislates for the investigation and remediation of polluted land and water on contaminated sites.

Crown Lands Act 1989: This Act governs the ownership and management of crown land.

Environment Planning and Assessment Act 1979: This Act provides a framework for environmental impact assessments and the development of policies and plans. In the lower Lachlan, particular consideration is to be given to impacts of developments on the ecological community which is listed as an endangered ecological community (EEC) under the Fisheries Management Act 1994.

Fisheries Management Act 1994: This Act aims to conserve and promote the ecologically sustainable use of the state’s fisheries. The listing under this Act of the lower Lachlan aquatic community as an EEC has considerable legal implications including penalties (up to a $220,000 fine and/or up to two years imprisonment) for harming species or causing damage (e.g. dredging riverbeds or constructing in-stream or floodplain barriers to fish passage) without appropriate authorisation.

Heritage Act 1977: This act affords protection to natural heritage features.

Local Government Act 1993: This specifies approval requirements for building, waste management, and sewerage and stormwater drainage.

Mining Act 1992: This provides a framework for the responsible development, management and use of mineral resources.

National Parks and Wildlife Act 1974: This Act protects all areas reserved as national parks, historic sites, nature reserves, Aboriginal areas, state recreation areas and regional parks as well as all native birds, reptiles, amphibians and mammals (except the dingo) in NSW.

Native Vegetation Management Act 2003: This Act allows for the management of native vegetation clearing through the development consent and planning process. Vegetation clearing may be permitted under authorised property vegetation plans approved under the Act. Clearing that constitutes a routine agricultural management activity or certain routine farming practices (other than clearing) may also be permitted.

Noxious Weeds Act 1993: This outlines landholder responsibilities for the control of noxious weeds and licence requirements for the use of herbicides.

Protection of the Environment Administration Act 1991: This Act affords protection and the capacity to restore and enhance the general quality of the environment in NSW through the principles of ecologically sustainable development.

Protection of the Environment Operations Act 1997: This outlines the requirements for licensing of activities that pollute water and the penalties for unlicensed pollution.

Yanga National Park 7 Soil Conservation Act 1938: This Act provides for the conservation of soil resources and farm water resources and for the mitigation of erosion.

Threatened Species Conservation Act 1995 (TSC Act): This Act provides a framework for the classification and protection of endangered species and critical habitats. Numerous species in the Yanga National Park are listed in the schedules of this Act.

Water Management Act 2000: This is the central state legislation governing the development, management and use of water resources throughout NSW.

Water Sharing Plan for the Murrumbidgee Regulated River Water Source 2003: A statutory water sharing plan developed under the provisions of the Water Management Act 2000 (DSNR 2003).

NSW State policy

NSW Fisheries Policy and Guidelines – Aquatic Habitat Management and Fish Conservation (1999): This gives background on fish habitats and resources and identifies activities impacting on aquatic habitats, compliance activities, guidelines for mitigating impacts, conservation and environmental assessment.

NSW Groundwater Policy Framework (1997), NSW Groundwater Dependent Ecosystems Framework (2002) and NSW Groundwater Quality Policy (1998): These documents provide a framework for the improved management of groundwater resources in NSW.

NSW Salinity Strategy (2000): The state policy to reduce the occurrence and impacts of salinity in NSW.

NSW State Rivers and Estuaries Policy (1993): This policy provides for the improvement in management of rivers and their floodplains through principles of sustainable management.

NSW Water Conservation Strategy (2000): This outlines strategies to promote the conservation of water resources in NSW.

NSW Weirs Policy (1997): This allows for the reduction and remediation of environmental impacts of weirs.

NSW Wetlands Management Policy (1996): This is the state policy on the management of wetlands and overseen by the NSW State Wetland Action Group.

Local Environmental Control Plans and Development Control Plans: These control local development and activities permitted in wetlands.

8 Description of wetland ecological character 2 Overview of Yanga National Park

2.1 Site location and its catchment

2.1.1 Site location and boundary Yanga National Park lies less than two kilometres east of the township of Balranald on the south bank of the Murrumbidgee River (Figure 3). The park has about 150 km Murrumbidgee River frontage running north-east to south-west from downstream of the confluence of the Lachlan and Murrumbidgee rivers to Balranald Weir. The national park includes: four significant lakes – Yanga Lake, Tala Lake, Piggery Lake, and Irrigation Lake extensive river red gum forest along the Murrumbidgee River (south) black box (Eucalyptus largiflorens) and lignum (Muehlenbeckia florulenta) woodland along the Sturt Highway hundreds of waterways including canals and creeks (e.g. Uara Creek).

2.1.2 Murrumbidgee catchment The Murrumbidgee catchment is the fourth largest in the Murray–Darling Basin, draining an area of over 84,000 km2 (Figure 4). The catchment consists of 6 749 km of streams (Norris et al. 2002), of which around 1500 km are the main channel of the Murrumbidgee River. The Murrumbidgee River starts in the Fiery Range of the Snowy Mountains, 1600 m above sea level, and flows into the Murray River at Boundary Bend at an altitude of 60 m. There are more than half a million people living in the Murrumbidgee catchment. Australia's capital, Canberra, with a population of 314,000 and NSW's largest inland city, and Wagga Wagga, with a population of 57,000, are both situated within the catchment (Murrumbidgee CMA 2006). Other major urban centres in the catchment include Balranald, Coleambally, Cooma, Cootamundra, Griffith, Gundagai, Hay, Henty, Junee, Leeton, Narrandera, Queanbeyan, Yass and Tumut. Agricultural production in the Murrumbidgee catchment is worth in excess of $1.9 billion a year, more than 16% of Australia’s total agricultural production (DSNR 2003). The agricultural industry, with more than 10,000 km of irrigation channels (Khan et al. 2004), provides 25% of NSW fruit and vegetable production, 42% of the state’s grapes and half of Australia's rice production. Other major industries in the catchment include dryland agriculture, including beef production, intensive poultry production, sheep and wool, cropping and softwood plantations (RRDB 2004). The Murrumbidgee catchment has one of the most diverse climates in NSW, varying from the cooler high alpine in the east to the hot plains of the west. Its annual rainfall varies from more than 1500 mm in the high country to less than 400 mm on the western plains. The annual evaporation averages about 1000 mm to 1800 mm, respectively. Under average climatic conditions about 24% of the rainfall in the 28,000 km2 river catchment above Wagga Wagga appears as runoff, contributing the majority of the river flow. Below Wagga Wagga, the runoff coefficient is less than 2% (Khan et al. 2004). Under natural conditions the river flows have a very strong seasonal pattern, with peak winter and spring flows driven by the reliable winter and spring rainfall and snow melt from the Great Dividing Range, and low flows in summer (Kingsford and Thomas 2001). The natural yearly flows in the Murrumbidgee average about 3800 GL, two thirds of that in the five months from June to October (Murrumbidgee CMA 2006).

Yanga National Park 9 Figure 3: Yanga National Park and the main waterways

10 Description of wetland ecological character The Murrumbidgee River is a highly regulated system and has 14 dams and 8 large weirs on its main course. The large dams include Burrinjuck Dam near Yass, with a capacity of 1026 GL, and Blowering Dam near Tumut, holding 1628 GL. These dams control water for the Murrumbidgee Irrigation Area (MIA) and the Coleambally Irrigation Area situated in the lower Murrumbidgee catchment (Murrumbidgee CMA 2006). The majority of land use in Murrumbidgee catchment is agricultural production, including cropping and grazing (Table 2; Figure 4). Approximately 10% of the catchment is managed for conservation, including national parks, nature reserves and forest reserves.

Figure 4: The Murrumbidgee catchment and main land use

Table 2: Major land use in the Murrumbidgee catchment

Land use Area (ha) Percentage ACT 235,743 2.89 Cropping 25,042 0.31 Cropping and grazing 2,467,162 30.28 Flood irrigation 439,350 5.39 Forestry and forest reserves 247,025 3.03 Grazing native/improved pasture 3,992,705 49.01 Horticulture 13,877 0.17 Limited grazing 367,496 4.51 Nature conservation and recreation 311,345 3.82 Urban 1353 0.02 Vacant 22,807 0.28 Water storage/lakes 23,356 0.29 Total 8,147,261 100 Source: OEH

Yanga National Park 11 2.2 Climate

Climate in Yanga National Park is classified as warm persistently dry grassland based on a modified Köppen classification system.1 The area has a semi-arid climate with low rainfall and hot summers.

Climatic data are recorded at a number of sites within the Murrumbidgee catchment. The nearest weather station is at Balranald, run by the Bureau of Meteorology (site no. 049002). The following information is extracted from 1889 to 2006 data. The average annual rainfall is about 320 mm. The average monthly rainfall distribution at Balranald is given in Figure 5 and other average monthly weather parameters – radiation and evaporation, maximum and minimum temperatures – are given in Figure 6 and Figure 7, respectively. Note that data are missing for some years.

Evaporation is an important factor in the water cycle of temperate climate regions, with high values in the summer months (daily average 7.44 mm) and lower values in winter months (daily average 2.54 mm). Mean monthly evaporation exceeds monthly rainfall throughout the year (by a factor of 10 or more during summer months).

33 Mean Monthly Rainfall at Balranald (BOM site No 049002)

19 Average Rainfall for 119 years (1889-2007) (mm) for 119 years (1889-2007) Average Rainfall 17

15 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

Data source: Bureau of Meteorology

Figure 5: Monthly rainfall distribution at Balranald, average for 119 years from 1889 to 2006

1 Bureau of Meteorology, www.bom.gov.au/iwk/climate_zones/index.shtml

12 Description of wetland ecological character 900 300 Mean monthly radiation and evaporation at Balranald 800 250 700 Mean Monthly Radiation Mean Monthly Evaporation 600 200

500 150 400 Evaporation (mm) Radiation (MJ/m2) 300 100

200 50 100

0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

Data source: Bureau of Meteorology

Figure 6: Mean monthly radiation and evaporation at Balranald, average of 118 years from 1889 to 2006

Mean daily maximum and minimun temperature at Balranald

Mean Daily Max 25 Mean Daily Min

15 Temperature Degree

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Data source: Bureau of Meteorology

Figure 7: Mean maximum and minimum temperatures at Balranald, average for 118 years from 1889 to 2006

Yanga National Park 13 2.3 Geology

The lower Murrumbidgee lies within the eastern Riverine Plains province of the Murray Geological Basin, a large saucer-shaped structure which extends into three states and covers about 300,000 km2 of south-eastern Australia (Lawson and Webb 1998). The Murray Basin consists of a sequence of mostly semi-consolidated to unconsolidated flat lying sedimentary deposits which began accumulating about 50 million years ago. They have a maximum thickness of about 600 m in the central area near Mildura and, within the lower Murrumbidgee, a maximum of about 400 m near Balranald. The maximum thickness at Narrandera, where the Murrumbidgee River enters the Murray Geologic Basin, is about 170 m (Kumar 2002).

In the low salinity area of the lower Murrumbidgee, the sedimentary deposits can be subdivided into three main units or layers. These layers are not actually separate, distinct aquifers. The three layers, in order of youngest (uppermost) to oldest (lowermost) are: Shepparton Formation Calivil Formation Renmark Group.

The Shepparton Formation extends from ground surface down to depths of 50–70 m, and is characterised by yellow and brown poorly sorted sands and clays. The proportion of sand is highly variable but mostly about 10–30%, with most occurring in the top 30 m. These sands are often referred to as ‘shallow aquifers’.

The Calivil Formation was deposited from 15 to 5 million years ago and is dominated by pale grey, coarse quartz sand with lenses of pale grey to white kaolinitic clay. The proportion of sand is typically 50–70%, making it the most productive layer not only within the low salinity area but also the entire eastern Murray Basin. Its thickness is generally 50–70 m. It is this layer (and the upper sand beds of the Renmark Group) that is generally referred to when the term ‘deep aquifer’ is used.

The Renmark Group sediments, which are the oldest deposits in the profile and hence began accumulating about 50 million years ago, are characterised by dark grey to black carbonaceous clay and dark brown lignite (a young form of coal). Coal and lignite deposits generally have significant amounts of sulfur associated with them, and the lignite could be a source of hydrogen sulfide (‘rotten egg gas’) emanating from some bores. The Renmark Group also contains thick sequences of grey, medium grained quartz sand which commonly comprises 30–50% of the entire unit. Many production bores extend into, and obtain groundwater from, Renmark Group sands. The Renmark Group thickness varies considerably in relation to the underlying bedrock surface, but has a maximum thickness of about 280 m in the lower Murrumbidgee low salinity area (Kumar 2002).

14 Description of wetland ecological character 2.4 Landform

Six soil landscapes occur in Yanga National Park (Walker 1991; Figure 8). Description of the six landforms and associated vegetation is given in Table 3.

2.5 Land tenure

The site is crown land dedicated as a national park under the NPW Act. Surrounding lands are primarily freehold. Before it was purchased by the Department of Environment and Conservation NSW (DEC) in 2005, the site was mostly freehold except for the 1932 ha of crown land of Yanga Nature Reserve.

2.5.1 Land use before dedication as a national park

Before being purchased by DEC, the majority (over 90%) of the land was used for grazing (Table 4; Figure 9).

Table 3: Description of soil landscapes in Yanga Nation Park

Landscape Description of soils and vegetation Riverland Plains with grey cracking and non-cracking clays, levees with texture-contrast soils, lunettes of deep calcareous sands; sparse to moderate river red gum, black box and river cooba along channels and in bends; moderate to dense lignum and nitre goosefoot; abundant grasses and forbs. Lowbidgee Plains with yellow-grey cracking clays, isolated brown and red texture- contrast soils; sandy solonised brown soils on prior streams; dense lignum, scattered bladder saltbush and cotton bush; depressions with canegrass and Dillon bush; isolated to clumped bluebushes; abundant forbs throughout. Murrumbidgee Plains with grey cracking and non-cracking clays; lunettes and rises of deep brownish sands; backplains of scalded yellow texture-contrast soils; moderate to dense black box, lignum, old man saltbush and nitre goosefoot; rises, lunettes and backplains with clumped mallee, white cypress pine, prickly wattle and scattered shrubs; abundant forbs and grasses. Yanga Loamy to sandy solonised brown soils and red texture-contrast soils; scattered belah, white cypress pine and mallee; scattered Dillon bush; abundant annuals. Victoria Lake beds, margins and channels of grey cracking clays and brownish sands; lunettes of deep, cemented sands; scattered to dense black box, lignum and nitre goosefoot along margins and channels; sparse prickly wattle and bluebushes on lunettes; copperburrs, forbs and annual grasses. Marma Levees of red and yellow texture-contrast soils and grey cracking clays; sandplains and lunettes of solonised brown soils and red texture-contrast soils; floodplains of grey cracking clays; scattered to dense bluebushes, bladder saltbush and old man saltbush; canegrass in swamps; abundant forbs, copperburrs and annual saltbushes.

Yanga National Park 15 Reproduced from Walker (1991)

Figure 8: Soil landscape in Lowbidgee

16 Description of wetland ecological character Table 4: Detailed land use in Yanga National Park before purchase by DEC

Land use type Area (ha) Area (%) Conservation area – National Park 1932.32 3.89 Cropping – continuous or rotation 238.65 0.48 Cropping – within controlled flood system 0.64 0.00 Cropping irrigated – rice 145.77 0.29 Grazing – irrigated pastures 381.28 0.77 Grazing – volunteer and naturalised and native or improved pastures 24,011.35 48.39 Grazing – volunteer and naturalised and native or improved pastures – with fixed irrigation system not used at the time of mapping 626.39 1.26 Grazing – wide road reserve or travelling stock route and with some grazing 24.87 0.05 Grazing – within controlled flood system (evidence of previous cropping) 1010.04 2.04 Grazing within bed of an ephemeral lake (evidence of previous cropping) 178.30 0.36 Low level forestry production and grazing 18,924.43 38.14 River and drainage system – flood chute 22.70 0.05 River and drainage system – flood or irrigation structure 0.12 0.00 River and drainage system – irrigation supply channel 13.02 0.03 River and drainage system – river and creek or other incised drainage feature 411.99 0.83 River and drainage system – waterway associated with controlled flooding/opportunistic cropping systems 43.64 0.09 Transport and other corridors – road or road reserve 23.12 0.05 Tree cover – native forest 182.99 0.37 Water body – reservoir 1130.78 2.28 Wetland – floodplain swamp – backswamp 196.33 0.40 Wetland – floodplain swamp – billabong 15.36 0.03 Wetland – swamp 104.41 0.21 Total 49,618.49 100.00

Data source: ABARES, http://adl.brs.gov.au/mapserv/landuse/

Yanga National Park 17 Data source: ABARES, http://adl.brs.gov.au/mapserv/landuse/ Areas marked ‘no data’ are mostly grazing land, and are not included in Table 4.

Figure 9: Land use in Yanga National Park before dedication as a national park

18 Description of wetland ecological character 2.6 Wetland types within Yanga National Park Yanga National Park covers an area of 66,743 ha and incorporates 12 different wetland types according to the Ramsar Convention classification system (Table 5) as a mosaic of permanent lakes and ponds to seasonal inundated woodland variously interconnected across time (driven by hydrology) and space (determined by geomorphology). According to the wetland classification system adopted by the ANZECC Wetlands Network (now known as the ANZECC Wetlands and Migratory Shorebirds Taskforce), which was modified from the Ramsar Convention classification system to suit the Australian situation, Environment Australia identified 10 types of wetland occurring within the Lowbidgee Floodplain (EA 2001). All 10 types occur in Yanga National Park.

Inland wetlands 1 Permanent rivers and streams: includes waterfalls. 2 Seasonal and irregular rivers and streams. 3 Riverine floodplains: includes river flats, flooded river basins, seasonally flooded grassland, savanna and palm savanna. 4 Seasonal/intermittent freshwater lakes (>8 ha), floodplain lakes. 5 Permanent freshwater ponds (<8 ha), marshes and swamps on inorganic soils, with emergent vegetation waterlogged for at least most of the growing season. 6 Seasonal/intermittent freshwater ponds and marshes on inorganic soils: includes sloughs, potholes; seasonally flooded meadows, sedge marshes. 7 Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on inorganic soils. 8 Freshwater swamp forest; seasonally flooded forest, wooded swamps; on inorganic soils.

Human-made wetlands 1 Water storage areas; reservoirs, barrages, hydro-electric dams, impoundments (generally >8 ha). 2 Irrigated land and irrigation channels: rice fields, canals, ditches.

2.7 Ecosystem services

When listed as nationally important wetlands (code NSW021) in 2000, the Lowbidgee floodplain met five of the seven selection criteria (EA 2001). Brief justifications for each of these criteria are given below. 1 It is a good example of a wetland type in a biogeographic region in Australia. 2 As mentioned before, there are 12 (10 according to Environment Australia) wetland types in Yanga National Park. The dominant wetland type, river red gum forest (tree-dominated freshwater wetlands) is one of the largest stands in Australia (AHC 1998). Other significant wetlands include Yanga Lake, Piggery Swamp, and seasonal flooded lignum woodland. 3 It is a wetland which plays an important ecological or hydrological role in the natural functioning of a major wetland system/complex. The wetland comprises the floodplain of the lower Murrumbidgee River, including Tala and Yanga lakes. During major floods, the system services as a large water retention basin absorbing the flood peak. Yanga National Park supports a diverse range of native flora and fauna species and vegetation types of biodiversity significance to the NSW Riverina Biogeographic Region.

Yanga National Park 19 4 It is a wetland which is important as the habitat for animal taxa at a vulnerable stage in their life cycles, or provides a refuge when adverse conditions such as drought prevail. In the arid and semi-arid inland, periodic drought is a prevailing feature. Yanga National Park has an array of permanent water bodies, including lakes, swamps, creeks and irrigation canals. They provide important drought refuges for biota, especially for waterbirds (Maher 1990; Kingsford and Thomas 2001). 5 The wetland supports 1% or more of the national populations of any native plant or animal taxa. At the time of listing, the Lachlan–Murrumbidgee confluence met the 1% population criterion for two migratory waterbirds: black-winged stilt (Himantopus himantopus) and red-necked avocet (Recurvirostra novaehollandiae) (Smith 1990). Yanga National Park alone may not meet this criterion, as the principal habitat for the two species is flooded cropland along the Pollen/Carira Creek (Maher 1990). 6 The wetland supports native plant or animal taxa or communities which are considered endangered or vulnerable at the national level. Yanga National Park supports the populations of a number of internationally and nationally threatened species included in the global red list of the World Conservation Union (IUCN) or listed under the EPBC Act. There are 12 vulnerable species, all of which are waterbirds, recorded in Yanga National Park over time, such as the Australasian bittern, freckled duck and blue-billed duck. The southern bell frog (Litoria raniformis), which is considered to be endangered at state level, has been recorded in Piggery Swamp, Mercedes Swamp and Twin-bridge Swamp.

Table 5: Wetland types found within Yanga National Park in order of dominance Ramsar Area Description code (ha)* Inland wetlands Freshwater, tree-dominated wetlands; includes freshwater swamp forests, Xf >30,000 seasonally flooded forests, wooded swamps on inorganic soils Shrub-dominated wetlands; shrub swamps, shrub-dominated freshwater W >10,000 marshes, shrub carr, alder thicket on inorganic soils P Seasonal/intermittent freshwater lakes (>8 ha); includes floodplain lakes >1600 M Permanent rivers/streams/creeks; includes waterfalls 411 Permanent freshwater marshes/pools; ponds (<8 ha), marshes and swamps Tp on inorganic soils with emergent vegetation waterlogged for at least most of the <100 growing season N Seasonal/intermittent/irregular rivers/streams/creeks 22 Seasonal/intermittent freshwater marshes/pools on inorganic soils; Ts >150 includes sloughs, potholes, seasonally flooded meadows, sedge marshes Human-made wetlands Seasonally flooded agricultural land (including intensively managed or 4 425 grazed wet meadow or pasture) 3 Irrigated land; includes irrigation channels and rice fields 159 Water storage areas; reservoirs/barrages/dams/impoundments 6 126 (generally >8 ha) 9 Canals and drainage channels, ditches 22 2 ^ Ponds, includes farm ponds, stock ponds, small tanks (generally <8 ha) # * Data sources: NPWS; McCosker (2008) ^ Not listed in EA (2001) # No information, or less than 10 ha

20 Description of wetland ecological character 3 Overall conceptual ecological model

An ecological model is a conceptual or mathematical representation of a natural phenomenon. Ecological models are abstractions or simplifications of the real world that portray the dominant components and key processes. Typically, models define relationships among states (components of the ecosystem) and transitions (processes that change the states). These relationships are the basis on which to predict changes in the ecological character over time depending upon trajectories of, or perturbations to, key processes. Ecological models are excellent tools for generating questions about the system behaviour and guiding decision making for planning and management. In addition, models also document and record major assumptions and current understanding of the system.

Wetland ecosystems are dynamic in space and time, with the given components and processes being primarily determined by the hydrogeologic settings, which are in turn determined by the climate and geomorphology (Figure 10). Climate, through precipitation, evaporation and transpiration, influences surface and groundwater flows and the hydrology and hydrological variability of wetlands. Geomorphology determines the size, shape and location of wetlands within the landscape, and the water sources, physico-chemical properties and soils as well. The natural drivers are strongly affected by human activities on the landscape, such as land use and water diversion, which will be addressed in the section on major threats to the sites (section 8). Following DEWHA (2008), the human interventions and disruptions (referred to as pressures, stressors or levers in some literature, such as Phillips et al. 2005) are treated as system drivers in the model.

The hydrogeologic setting of the landscape is the master variable driving wetland form and function. Hydrogeologic setting is defined by topography, soils, subsurface geology and climate, and drives groundwater and surface water movement patterns. The formation, distribution, and biogeochemistry of individual wetlands are based on the interaction between these groundwater and surface water movement patterns and climate.

Models of critical processes, such as hydrological regimes and nutrient cycling, will be developed and presented in section 6 when describing those processes.

Yanga National Park 21 Management (D) Climate (D) Geomorphology (D) Human disturbance (D) EWAs Rainfall Fractures and faults River regulation Re-snagging Temperature Surface geology (bedrock Water diversion Dam removal Evaporation & soil types) Drainage network Levee breach Wind Topography Infrastructure Weed and pest control Solar radiation Aquifers Grazing Erosion control Extreme events Clearing Burning Hydrogeologic Settings (D) Agricultural runoff

Hydrological regimes (C) Wetland Frequency, duration and depth of inundation Ecosystem Groundwater recharge/discharge Dry-wet cycles

Primary Production and Trophic Structure (C)

Modified from Wetlands and Waterbirds Taskforce (2007). Feedback from biota to their environment and interactions among biological communities were omitted from the model for simplicity. D = Driver, C = Component, P = Process.

Figure 10: Overall ecological conceptual model for Yanga National Park

22 Description of wetland ecological character 4 Ecological services and benefits

The ecosystem services that support the ecological character of Yanga National Park have been described below in detail. These services are closely related. A summary of selected services, their condition and trend are shown in Table 6, which adapted the classification system of the Millennium Ecosystem Assessment (MEA 2005).

4.1 Regulating services

4.1.1 Maintaining regional water quality

Yanga National Park lies at the downstream end of the Lowbidgee floodplain, which is characterised by meandering channels and wide floodplains. The land is generally flat to gently sloping and vegetated. During floods, up to 85% of the water in the Murrumbidgee River flows through the floodplain (DWR 1991). As water flows through the floodplain, the system effectively retains, recycles and removes suspended solids, organic and inorganic nutrients, and other pollutants from the water through several mechanisms, including (Sather and Smith 1984, cited by Mitsch and Gosselink 2000): a reduction in water velocity favouring sedimentation a variety of anaerobic and aerobic processes promoting denitrification, chemical precipitation, and other chemical reactions that remove certain chemicals from water a high rate of productivity that leads to high rates of mineral uptake by vegetation and subsequent burial in sediments when plants die a diversity of decomposers and decomposition process in sediments a large contact surface of water with sediment because of the water’s shallowness, leading to significant sediment–water exchange an accumulation of organic peat that causes the permanent burial of chemicals.

Currently, there are no data to quantify this service.

4.1.2 Replenish groundwater

In general, the shallow aquifers (e.g. Upper Shepparton Formation aquifer) underlying the floodplain are continually being recharged by rainwater that infiltrates the ground, by floods, by interconnected water bodies, and by leakage from nearby aquifers (Figure 11). The critical components in maintaining the level of groundwater recharge are indicated below. However, there is no quantitative information on the relationship between groundwater recharge and the components that maintain the service.

As mentioned in section 2.2, the mean annual rainfall and evaporation is 320 mm and 1814 mm, respectively. In such a dry environment, the recharge from rainwater to replenish groundwater is minimal. In the semi-arid lower Murray–Darling region, recharge from rainwater is generally less than 1 mm/yr (DIPNR 2003).

The major groundwater recharging corresponds to floods. During floods, the over-bank flows are retained by an array of land features in the floodplain, including ephemeral wetlands (e.g. Lake Yanga and Piggery Lake), creeks (e.g. Uara Creek), irrigation storages and depressions. The retained floodwater provides the major water input which percolates to aquifers.

Yanga National Park 23 Table 6: Ecosystem benefits and services MEA Ramsar Ecosystem service Condition category criteria Maintain regional water quality 1 Losing Replenish groundwater 1 Declining Regulating Flood control 1 Maintained Regulate climate 1 Declining Provides a combination of wetland types and habitats 1 Losing Support populations of biota species for maintaining the 3 Declining biodiversity of the NSW Riverina Bioregion Support 20 threatened faunal species 2, 3, 4 Support four threatened flora species 3, 4 Support at least one threatened fish species 3, 4 Supporting Support three endangered ecological communities 3,4 Supporting eleven migratory bird species protected by 3,4 international agreements Provide an important source of food, spawning ground 8 Declining and nursery for fishes Supports large stands of primary producers 1, 8 Declining Provide drought refuge for waterbirds and other fauna 4 Losing Aboriginal heritage Sustained European historical sites Sustained Cultural services Recreation and tourism: camping, touring, bushwalking Increasing Nature observation, research site for ecology, natural Increasing resources, biodiversity conservation

Modified from Jolly and Walker (1995)

Figure 11: Schematic of the conceptual model for groundwater, illustrating the major recharge areas in the floodplain

24 Description of wetland ecological character In a study of the irrigation and groundwater interactions in the MIA, Khan et al. (2004) found that hydrographs of groundwater piezometers showed a cyclic response indicating a periodic recharge and discharge during the irrigation and non-irrigation periods. The irrigation practices (e.g. irrigated pasture, rice paddy) within the national park and adjacent areas would have similar effects on the groundwater.

Vegetation cover is unlikely to influence the rate of recharge significantly as most recharge occurs when excess water is available during floods. However, transpiration by river red gums is thought to be a factor in maintaining lower groundwater levels in the Upper Shepparton Formation in semi-arid regions (such as Yanga National Park) relative to those in the aquifer in adjacent cleared dryland and irrigation areas (Thorburn and Walker 1994). River red gums have some roots (‘sinkers’) that penetrate more than 10 m into the subsoil to reach sandy aquifers (Bacon et al. 1993). A significant change in river red gum distribution is unlikely unless there are major bush fires. It is suggested that it is more appropriate to continuously monitor groundwater tables in the river red gum forest and adjacent areas than to monitor groundwater recharge or the components that maintain this service. A change in the ecological character for this service would be signalled by a significant change in the depth of the water table.

4.1.3 Flood control

The floodplain within Yanga National Park (and the adjacent Lowbidgee Irrigation District) acts as a large water retention basin, intercepting storm runoff and storing storm water, thereby changing the sharp runoff peaks to slower discharges over a longer period of time (Figure 12). For example, Yanga Lake has a capacity of around 6 GL (R Hampton 2008, pers. comm.). Because it is the peak flows that usually produce flood damage, the effect of the floodplain system is to reduce the danger of flooding.

4.1.4 Regulate climate

Yanga National Park is most likely to influence the local and global climate through land cover and biologically mediated processes, for instance, carbon sequestration. However, there does not appear to be sufficient data and a generally accepted method to quantify this service.

Storm Flow Rate

Wetlands

Without Wetlands

Time

Source: Kusler (1983) Figure 12: The effect of wetlands on peak stormwater flows

Yanga National Park 25 4.2 Supporting services

4.2.1 Provides a combination of wetland types, which is typical in the NSW Riverina Bioregion

The NSW Riverina Bioregion lies in south-west NSW, extending into central northern Victoria. The bioregion is approximately 9,576,964 ha, with 7,090,008 ha or 74.03% of it lying in NSW (IBRA 5.1). The NSW portion of the bioregion occupies approximately 8.86% of the state (Eardley 1999; IBRA 5.1).

The Riverina Bioregion extends from Ivanhoe in the Murray–Darling Depression Bioregion south to Bendigo, and from Narrandera in the east to Balranald in the west. Major towns within the boundaries include Hay, Coleambally, Deniliquin, Leeton, Mossgiel, Hillston, Booligal, Balranald and Wentworth. The bioregion also includes outlying remnants of the Murray–Darling Depression Bioregion on its western boundary, and the Victorian Midlands Bioregion in the south.

The Murray and Murrumbidgee rivers and their major tributaries, the Lachlan and Goulburn rivers, flow from the highlands in the east, westward across the Riverina plain.

Yanga National Park is part of the Murrumbidgee–Lachlan confluence, one of eight wetland systems identified as having bioregional significance in the Riverina (NLWRA 2002). Prior to 2000, the wetlands of the Riverina Bioregion were described as being in fair to degraded condition (NLWRA 2002). Changed hydrology is a key threat to all of these wetlands, but there are also impacts from feral animals, exotic weeds, water extraction, regulation and diversion, altered nutrient levels, salinity, grazing pressure, reduced flows and water storage use. As a newly gazetted national park, a wide range of measures aiming to preserve and enhance the area for nature conservation have been commenced, including the preparation of a management plan.

Wetland types in Yanga National Park include freshwater forested wetlands, shrub swamps and seasonal marshes (Table 5).

4.2.2 Supports biota species that maintain biodiversity of the NSW Riverina Bioregion

Yanga National Park is one of the most biologically diverse areas in the NSW Riverina Bioregion, especially for avifauna (nearly 60% of birds recorded in the NSW Riverina Bioregion can be found in Yanga National Park: Table 7; Appendix 2). The site’s rich natural heritage – landforms and substrate types, animal and fish habitat, vegetation cover and distribution, faunal and floral species – provides the basis for maintaining the biodiversity of the bioregion, and the state’s economy and standard of living.

The floodplain, characterised by vegetation mosaics changing from high ground saltbush (Atriplex nummularia) shrubland and prickly wattle (Acacia victoriae) woodland, to black box woodland, river red gum forest and aquatic marshes, hosts more than 300 vascular plant species (Appendix 1). The diverse range of vegetation provides habitat for various animals. There are 269 fauna species (excluding fish) reported from Yanga National Park – these would contribute significantly to the biological diversity of the NSW Riverina Bioregion (see section 5.3.3 for fish species). Of these 269 species, 210 are birds (Appendix 2), 11 are amphibians, 24 are mammals (of which nine are introduced species), and 24 are reptiles (Table 7; species lists in sections 5.3.4, 5.3.5 and 5.3.6).

26 Description of wetland ecological character Table 7: Fauna and flora records in Yanga National Park and the NSW Riverina Bioregion

Group Riverina NSW Yanga National Park Occurrence (%) Bird 362 210 58.0 Mammal 89 25 27.0 Reptile 86 24 27.9 Amphibian 27 11 40.7 Plant 1,894 303 16.0 Fish* 18

Data sources: Pressey et al. (1984); Maher (1990); Robertson et al. (1994); Bales (1999); Atlas of NSW Wildlife; Spencer and Allman (2008); Wassens et al. (2008a) * Including the Murrumbidgee channel. Data source: Baumgartner (2004). No fish species are recorded in the Atlas of NSW Wildlife for NSW Riverina Bioregion.

4.2.3 Supports two endangered ecological communities

There are two ecological communities within Yanga National Park which are listed as endangered under the TSC Act: Myall woodland, and an aquatic ecological community in the natural drainage system of the lower Murray River catchment.

Aquatic ecological community in the natural drainage system of the lower Murray River catchment

The lower Murray ecological community includes all native fish and aquatic invertebrates within all natural creeks, rivers and associated lagoons, billabongs and lakes of the regulated portions of the Murray River below the Hume Weir, the Murrumbidgee River below Burrinjuck Dam, and the Tumut River below Blowering Dam, as well as all their tributaries and branches (Fisheries Scientific Committee 2001). These tributaries and branches include Billabong Creek, Yanco Creek, Colombo Creek and their tributaries, the Edward River and the Wakool River and their tributaries, Frenchmans Creek, the Rufus River and Lake Victoria. Excluded from the definition are the Lachlan River and the Darling River and their tributaries. Artificial canals, water distribution and drainage works, farm dams and off-stream reservoirs are also excluded. The community includes 23 native fish species and over 400 recorded native invertebrate species.

In Yanga National Park, diverse habitats accommodate this EEC (Figure 13), including permanent and intermittent river channels, intermittent swamps, and billabongs. The modification of natural river flows as a result of river regulation (dams, weirs) was identified as the main threat to this EEC. The changed river flow regimes lead to reduced habitat quality, loss of spawning cues, and reduced opportunities for dispersal and migration. Grazing also contributes to the degradation; however, the exclusion of livestock after gazettal as a national park should ease this pressure.

Yanga National Park 27 Photo: L Wen/OEH Figure 13: Twin-bridges Swamp, a freshwater wetland in Yanga National Park, which accommodates the threatened aquatic ecological community including the southern bell frog

Myall woodland in the Darling Riverine Plains, Brigalow Belt South, Cobar Peneplain, Murray–Darling Depression, Riverina and South Western Slopes bioregions

This ecological community is scattered across the eastern parts of the alluvial plains of the Murray–Darling River system. Typically, it occurs on red-brown earths and heavy textured grey and brown alluvial soils within a climatic belt receiving between 375 and 500 mm mean annual rainfall. The structure of the community varies from low woodland and low open woodland to low sparse woodland or open shrubland, depending on site quality and disturbance history. The tree layer grows up to a height of about 10 m and invariably includes weeping myall or boree (Acacia pendula) as one of the dominant species or the only tree species present. The understorey includes an open layer of chenopod shrubs and other woody plant species and an open to continuous groundcover of grasses and herbs (NSW Scientific Committee 2005).

There are currently about 30 ha of Myall woodland in Yanga National Park (McCosker 2008) located north of Yanga Lake. While land clearing and overgrazing by feral and domestic animals were the major threats prior to 2005, grazing by rabbits is an ongoing risk to the community.

28 Description of wetland ecological character 4.2.4 Supports 21 threatened fauna species

Historically, 21 endangered or vulnerable fauna have been recorded within Yanga National Park and in its vicinity (Table 8). The endangered species include three birds, one amphibian and one reptile, while the vulnerable species include 14 birds and two mammals. One waterbird species, the little bittern (Ixobrychus minutus), is not included in Table 8 because it is not listed as threatened in the EPBC Act or TSC Act. However, it is listed as threatened in the Victorian Flora and Fauna Guarantee Act 1988 and as endangered in the Advisory list of threatened vertebrate fauna in Victoria – 2007 (DSE 2007).

The threatened square-tailed kite (Lophoictinia isura) was recorded in 1989/1990 and 2005/2006 waterbird surveys (Maher 1990, 2006), and on a number of other occasions (Atlas of NSW Wildlife). The species breeds in south-western Australia and in wetter parts of southern and eastern Australia, with birds from southern Australia probably overwintering in the tropics (Debus 1983; Blakers et al. 1984; Debus and Silveira 1989; Johnstone and Storr 1998). Square-tailed kites require a large area of open forest to support a single pair as they feed mainly on nestling birds and eggs (Barnes et al. 1999), and appear to prefer a landscape that is structurally diverse (Debus and Czechura 1989). The diverse vegetation types ranging from river red gum forest, black box woodland and old man saltbush shrubland in Yanga National Park (section 5.3.1) provide a regular breeding habitat for the species.

It should be pointed out that there are only a few systematic fauna surveys in Yanga National Park, especially for nocturnal species; therefore it is highly possible that other threatened species occupy the park. For example, three bat species – inland forest bat (Vespadelus baverstocki), little pied bat (Chalinolobus picatus) and large-footed myotis (Myotis adversus) – are known to be associated with inland riverine forests and freshwater wetlands in the Murrumbidgee catchment (Churchill 1998). Although there are no records in the Atlas of NSW Wildlife for Yanga National Park, it is likely that the three threatened species inhabit the park.

The loss, fragmentation and degradation of habitats were identified as major threats for a majority of the species listed by the NSW Scientific Committee. Yanga National Park contains suitable breeding, nursing, and foraging/hunting habitats that can support the persistence of those threatened species.

4.2.5 Supports four endangered and vulnerable plant species

Two endangered and two vulnerable flora species were recorded in Yanga National Park (Table 9). The austral pipewort (Eriocaulon australasicum) was last seen in 1853. The other three species were recorded recently (1990s). Thirteen threatened plant species are known or predicted to occur in the lower Murrumbidgee region, such as lanky buttons (Leptorhynchos orientalis) and silky swainson-pea (Swainsona sericea).2 As there has been no systematic flora survey in Yanga National Park, more threatened flora species are likely to occur in the park.

2 www.threatenedspecies.environment.nsw.gov.au

Yanga National Park 29 Table 8: Endangered and vulnerable fauna found within Yanga National Park Legal Class Family Scientific name Common name Last sighting status Amphibian Hylidae Litoria raniformis Southern bell frog E January 2009 Aves Acanthizidae Pyrrholaemus Redthroat V 18/09/1991 brunneus Accipitridae Lophoictinia isura Square-tailed kite V 22/12/2005 Anatidae Oxyura australis Blue-billed duck V 21/12/2005 Stictonetta naevosa Freckled duck V 22/12/2005 Anseranatidae Anseranas Magpie goose V 19/11/1989 semipalmata Ardeidae Botaurus poiciloptilus Australasian V 12/01/2006 bittern Burhinidae Burhinus grallarius Bush stone- E 31/12/1981 curlew Cacatuidae Cacatua leadbeateri Major Mitchell's V 20/10/2000 cockatoo Climacteridae Climacteris picumnus Brown V 22/01/2008 treecreeper Eupetidae Cinclosoma castanotus Chestnut quail- V 31/12/1981 thrush Meliphagidae Grantiella picta Painted V 1/02/1997 honeyeater Petroicidae Melanodryas cucullata Hooded robin V November 1998 Pomatostomidae Pomatostomus Grey-crowned V December 2005 temporalis temporalis babbler Psittacidae Polytelis anthopeplus Regent parrot E 1/02/1997 monarchoides (eastern subsp.) Polytelis swainsonii Superb parrot V 7/11/1977 Rostratulidae Rostratula Painted snipe E 10/01/1990 benghalensis australis Strigidae Ninox connivens Barking owl V 31/12/1981 Mammalia Dasyuridae Dasyurus maculatus Spotted-tailed V 30/06/2004 quoll Vespertilionidae Myotis Macropus Large-footed bat V March 2009 Reptilia Elapidae Echiopsis curta Bardick E 31/12/1974

E = Endangered, V = Vulnerable. Data sources: Bales (1999); Maher (1990, 2006); Atlas of NSW Wildlife; Spenser and Allman (2008); M Pennay (2009, pers. comm.)

Table 9: Endangered and vulnerable plant species found in Yanga National Park

Family Scientific name Common name Status Sightings Eriocaulaceae Eriocaulon Austral pipewort E 1 australasicum Brassicaceae Lepidium monoplocoides Winged peppercress E 1 Solanaceae Solanum karsense Menindee nightshade V 1 Fabaceae/Faboideae Swainsona murrayana Slender darling pea V 1

Data source: Atlas of NSW Wildlife

30 Description of wetland ecological character 4.2.6 Supports at least one threatened fish species Historically, four threatened fish species – Murray hardyhead (Craterocephalus fluviatilis), silver perch (Bidyanus bidyanus), olive perchlet (Ambassis agassizii) and southern purple-spotted gudgeon (Mogurnda adspersa) – are known to occur in the lower Murrumbidgee (Gilligan 2005). However, a catchment-scale fish survey (Gilligan 2005) and river reach scale survey (Baumgartner 2004) only detected silver perch. Gilligan (2005) concluded that the other three species were likely to be extinct locally.

4.2.7 Supports an abundance of waterbirds In the past the Lowbidgee has regularly supported more than 50,000 waterbirds, and sometimes more than 100,000, including some of the largest breeding colonies of straw-necked ibis (Threskiornis spinicollis) in Australia (DWR 1994). In the wet year of 1983, the swamps in the Lowbidgee supported more than 100,000 waterbirds (Kingsford and Thomas 2001). The most abundant species include grey teal (Anas gracilis), pink-eared duck (Malacorhynchus membranaceus) and Eurasian coot (Fulica atra) (Pressey et al. 1984). Floodplain wetlands within Yanga National Park, including riparian river red gum forests, vegetated swamps (such as Shaw’s Swamp, Breer, Twin-bridges, Narkungerie) and open water lakes (Tala Lake, Yanga Lake, Piggery Lake), creeks (Monkem Creek, Uara Creek), historically support large numbers of waterbird colonies. A comprehensive waterbird survey in the Lachlan–Murrumbidgee confluence in 1989– 90 covered nine significant wetlands in Yanga National Park (Maher 1990). The survey recorded a total of 61 waterbird species. Most of these species were found in Yanga National Park. Those of national, state and regional importance are listed in Table 10. Maher (1990) identified four wetlands as important breeding areas for colonial nesting and other waterbirds – Tarwillie Swamp, Shaw’s Swamp, Piggery Lake and Waugorah Creek – where large numbers of nests were located (Figure 14). For example, at Shaw’s Swamp, 500 little pied cormorant (Phalacrocorax melanoleucos) nests were recorded. In Tarwillie Swamp, 800 little pied cormorant, 400 little black cormorant and 200 great egret nests were recorded. Particularly important are the river red gum forests, which are the traditional nesting habitat for egrets in south-eastern Australia, and the species shows a reluctance to breed away from these areas (Maher 1990; Briggs et al. 1997). Important feeding areas in Yanga National Park include Tarwillie Swamp, Shaw’s Swamp, Piggery Lake, Two-Bridge Swamp between Redbank Weir and Lambing Down Hill, and river red gum forests within 10 km of Redbank Weir along the Murrumbidgee River (Figure 14). A long-term waterbird monitoring program covering the Lowbidgee floodplain is the Aerial Surveys of Waterbirds in Eastern Australia (Kingsford and Porter 2006) managed by the University of NSW and OEH, which started in 1983. The survey produced a series of occasional papers and annual summary reports (Kingsford et al. 2008). Although not specific for Yanga National Park, these reports indicate that the floodplain supported large numbers of waterbird species and colonial birds, such as egrets, spoonbills and ibis, in the 1980s and early 1990s. However, the survey found that waterbird numbers collapsed by 90%, from an average of 139,939 (1983–86) to 14,170 (1998–2001) in the Lowbidgee (Kingsford and Thomas 2001). Similar declines occurred across all functional groups: piscivores (82%), herbivores (87%), ducks and small grebe species (90%), large wading birds (91%) and small wading birds (95%).

Yanga National Park 31 The decline in waterbird populations was evidenced throughout Australia (Kingsford 2003; Kingsford and Thomas 2004; Phillips and Muller 2006; Nebel et al. 2008), and worldwide (Wetland International 2006). For example, between the 1980s and 2006, Nebel et al. (2008) estimated that the mean number of migratory shorebirds declined by 73% while the Australian resident waterbird population fell by 81% in eastern Australia. In this sense, the Lowbidgee floodplain still remains as significant breeding, feeding and nestling habitat contributing to sustaining the waterbird population, especially in inland Australia, regardless of the low numbers of waterbirds recorded recently.

Table 10: Waterbird species of national, state and regional importance recorded in the 1989–90 survey in Yanga National Park

Family name Scientific name Common name Importance level Accipitridae Circus approximans Swamp harrier State Haliastur sphenurus Whistling kite Regional Anatidae Anas castanea Chestnut teal Regional Anas gracilis Grey teal State Anas rhynchotis Australasian shoveler State Anas superciliosa Pacific black duck State Aythya australis Hardhead State Biziura lobata Musk duck State Cygnus atratus Black swan State Oxyura australis Blue-billed duck State Stictonetta naevosa Freckled duck National Anhingidae Anhinga melanogaster Darter State Ardeidae Ardea alba Great egret National Ardea intermedia Intermediate egret National Ardea pacifica White-necked heron State Botaurus poiciloptilus Australasian bittern National Egretta garzetta Little egret National Ixobrychus minutus Little bittern National Nycticorax caledonicus Nankeen night heron State Charadriidae Erythrogonys cinctus Red-kneed dotterel State Phalacrocoracidae Phalacrocorax carbo Great cormorant Regional Phalacrocorax melanoleucos Little Pied cormorant State Phalacrocorax sulcirostris Little Black cormorant State Podicipedidae Podiceps cristatus Great crested grebe State Rallidae Fulica atra Eurasian coot State Gallinula ventralis Black-tailed native-hen Regional Gallirallus philippensis Buff-banded rail State Porphyrio porphyrio Purple swamphen Regional Porzana pusilla Baillon's crake State Recurvirostridae Himantopus himantopus Black-winged stilt State Threskiornithidae Platalea flavipes Yellow-billed spoonbill State Platalea regia Royal spoonbill National

Data source: Maher (1990)

32 Description of wetland ecological character Data source: Maher (1990)

Figure 14: Important waterbird feeding and breeding sites in Yanga National Park identified during the 1989–90 survey

Yanga National Park 33 4.2.8 Supports 11 migratory species covered in migratory bird agreements

The Lachlan–Murrumbidgee confluence was identified as an important migratory waterbird habitat (Pressey et al. 1984) in NSW and was covered in the Wildlife Conservation Plan for Migratory Shorebirds (DEH 2006) based on the population size of black-winged stilts (Himantopus Himantopus) and red-necked avocets (Recurvirostra novaehollandiae).

There are 11 migratory species covered by the international agreements for migratory birds (JAMBA, CAMBA, and ROKAMBA) recorded in Yanga National Park and adjacent areas. Most of the species recorded are listed in Table 11 and were considered uncommon or rare in the 1989–90 bird survey, except glossy ibis (Plegadis falcinellus), over 1000 nests of which were located in Suicide Swamp (Maher 1990).

Thirty-six species of migratory shorebirds regularly visit Australia, five of which have been recorded in Yanga National Park (Table 11), such as the sharp-tailed sandpiper (Calidris acuminate) and fork-tailed swift (Apus pacificus) (DEH 2006).

4.2.9 Supports large stands of primary producers

The Yanga floodplain is very productive, and was used extensively for agriculture and farming prior to 2005.

Currently, the majority of the national park is vegetated. In particular, there are over 21,000 ha of river red gum forests and about 12,000 ha of black box woodlands (McCosker 2008) which fuel river productivity though litter fall (Robertson et al. 1999; Gawne et al. 2007). The annual litter production of river red gum forest is amongst the highest in Australia (Briggs and Maher 1983). Although primary productivity has not been investigated for any of the vegetation community in Yanga National Park, using the range measured by Briggs and Maher (1983) in the same region the river red gum forests alone produce 78,378–123,195 tonnes of litter (leaf, fruit, flower, twigs and bark) annually.

Table 11: Migratory birds protected under international treaties

Family Common name Scientific name Legal status Apodidae Fork-tailed swift * Apus pacificus C, J, K Ardeidae Great egret Ardea alba C, J Cattle egret Ardea ibis C, J Accipitridae White-bellied sea eagle Haliaeetus leucogaster C Threskiornithidae Glossy ibis Plegadis falcinellus C Rostratulidae Painted snipe Rostratula benghalensis C Scolopacidae Black-tailed godwit Limosa limosa C, J, K Sharp-tailed sandpiper * Calidris acuminate C, J, K Latham's snipe * Gallinago hardwickii J Greenshank * Tringa nebularia C, J, K Marsh sandpiper * Tringa stagnatilis C, J, K

C = CAMBA, J = JAMBA, K = ROKAMBA * Listed in DEH (2006)

34 Description of wetland ecological character 4.2.10 Provides important feeding, spawning and nursing grounds for native fish

An extensive part of Yanga National Park can be inundated and is hydrologically linked with the Murrumbidgee River during overbank flow and flooding. Under flooding conditions, the national park provides extremely diverse habitats for fish. When inundated, many animals emerge from eggs, cysts and burrows in the soil, and become extremely productive (Baldwin and Mitchell 2000). A variety of aquatic fauna, including fish and reptiles, move from the main channel to floodplain habitats during overbank flows to take advantage of the rich food resources (Figure 15).

Fish use floodplain habitats for a variety of reasons, including shelter, feeding, spawning and recruitment (Junk et al. 1989). These habitats provide shelter during floods, away from the fast flows of the main channel. The low water velocity and high productivity of floodplain habitats makes them important feeding and nursery areas. Spawning in floodplain habitats can provide larvae and juveniles with safer conditions (e.g. protection from predation) and more food than the main waterway channel. Many south-eastern fish (see Table 18), such as silver perch (Bidyanus bidyanus), golden perch (Macquaria ambigua) and bony herring (Nematalosa ereb), spawn and shelter in floodplain habitats. The Murray hardyhead (Craterocephalus fluviatilis), an endangered species in the Murray–Darling Basin, lives along the edges of slow-flowing lowland rivers and in lakes, billabongs and backwaters. Although these species use floodplain habitats, there has been little research done on the importance of these habitats for them. Fish movement during flooding is generally unknown, and the dependence on the floodplain has not been thoroughly researched.

As the floodplain becomes more isolated from the Murrumbidgee River due to catchment-scale regulation and reach-scale development, Yanga National Park and the Lowbidgee floodplain are losing this service. For example, according to the latest fish survey, the introduced European carp dominated the majority of sampled habitats (Spencer and Allman 2008).

Based on Mussared (1997) Figure 15: Floodplain wetlands as fish feeding, spawning and nursery habitat

Yanga National Park 35 4.3 Cultural services

4.3.1 Aboriginal heritage

Yanga National Park lies within the traditional tribal areas of both the Muthi Muthi and Wathi Wathi peoples, and has a rich Aboriginal heritage including associations with creation stories (Roberts 2005). Sites on the property already listed on the Aboriginal sites register include mounds, scarred trees, historic sites, burials and middens. Such sites and artefacts are highly valued by the Aboriginal community, as well as by the broader community. It is important that these sites are conserved as fragile and irreplaceable Aboriginal heritage, and the need to protect this heritage is recognised in legislation. The NSW National Parks and Wildlife Service (NPWS) has a statutory role in the protection and preservation of Aboriginal sites. The concern is essentially the need to reinforce the importance of this heritage, and ensure that Aboriginal sites and artefacts are reported to NPWS.

4.3.2 European heritage

Yanga National Park is an area of significance for early European settlement of the NSW Western plains. Yanga Station covered approximately 210,000 acres and was the largest privately owned station in the southern hemisphere. Yanga homestead was built around 1870 by the new owner, Dr (Sir) Charles Nicholson, for the station manager. Located 10 km south-east of Balranald, the homestead is of Georgian bungalow style with typically 1830s and 1840s features (Figure 16). It is situated on a rise looking eastward over terraced gardens and Yanga Lake. Yanga Station is recorded as being the first private property in Australia to have a telephone. The property also contains evidence of early horse and coach transport, early 20th century rail transport and soldier settlement blocks.

4.3.3 Scientific research

Yanga National Park has, since its gazettal, become a focus of inland floodplain wetland research. A number of studies covering hydrology, geomorphology, ecology, botany and zoology are underway at Yanga National Park and the broader Lowbidgee floodplain.

Photo: NPWS Figure 16: Yanga homestead

36 Description of wetland ecological character 5 Description of specified components that support selected ecosystem services Ecosystems consist of various non-living, abiotic and living biotic components. The Ramsar Convention (2005) defines ecosystem components as the physical, chemical and biological parts of a wetland. The abiotic components of an ecosystem include various physical and chemical factors. The physical factors that have the greatest effect on the ecological character of Yanga National Park are: climate (section 2) wetland size and connectivity woody debris soil and sediment (structure, texture, and profile) fire. The chemical factors include: soil and sediment chemical properties (organic content, salt, nutrient level, pH) water chemistry (total and bioavailable nutrient levels, salinity, pH, dissolved oxygen, toxic substance concentration). Organisms that make up the biotic component of an ecosystem are usually classified as autotrophs and heterotrophs, based on how they get the food or organic nutrients they need to survive, and include: autotrophs (producers): terrestrial vegetation communities, aquatic plants and phytoplankton, and periphytyes heterotrophs (consumers): zooplankton, macroinvertebrates, vertebrates (fish, amphibians, reptiles, waterbirds, and other mammals) detritivores (decomposers and detritus feeders) and benthic microorganisms: various bacteria and fungi. Ecosystem components included in the description of wetland ecological character for Yanga National Park are summarised in Table 12.

5.1 Physical components of Yanga National Park

5.1.1 Important wetlands The important wetlands (and wetland systems) and their basic features are listed in Table 13. Their locations are mapped in Figure 17. Yanga Lake is about 8 km west of Balranald and at 1247 ha is the largest ‘permanent’ lake in the Balranald region. When full, it has about 24 km of shoreline. As early as the 1920s its environmental services and conservation values were noticed. For example, in 1909 the lake was noted as a reserve ‘for the reservation of Game’. In 1922, it was noted as a ‘sanctuary for birds and animals’. In 1923, the Australasian newspaper stated Lake Yanga was ‘an immense sheet of fresh water which had never been known to fail.’

However, as water development in the Murrumbidgee catchment progressed, especially the completion of Burrinjuck Dam and expansion of the MIA in the late 1920s (see Table 23 for major developments), Yanga Lake has had less chance to be flooded. In addition, Yanga Lake was not included in the area gazetted as the

Yanga National Park 37 Lowbidgee Flood Control and Irrigation District (FCID) in the 1940s. As a result, artificial floods to assist the Lowbidgee are unlikely to reach Yanga Lake. Consequently, the ‘permanent’ lake dried up in 2001 and has stayed dry since then. The long-term dry period eradicated the aquatic biota, and saltbush has developed (Figure 18). Tala Lake used to be a vast expanse of deep open water with river red gums scattered around its periphery. It was used as an irrigation water storage. Before it dried up in 2001, the water level was maintained at an artificial high level resulting in the death of some old river red gums (Figure 19). Piggery Lake is a large shallow lake with mean depth of about 1.5 m and can hold water for up to 18 months (Pressey et al. 1984). It is surrounded by river red gums and has extensive beds of common water milfoil (Myriophyllum propinquum) and water primrose (Ludwigia peploides) when inundated (Figure 20). A series of banks has been constructed to hold water in the lake. Shallow marshes include Two Bridges Swamp (Figure 21) and Mercedes Swamp (Figure 22). Tall spike rush (Eleocharis sphacelata) is the dominant aquatic plant in these swamps. It can grow as understorey in sparse river red gum forest or form dense single species stands.

Table 12: Ecosystem components of Yanga National Park

Category Components Condition and trend Physical Important wetland Stressed and declining Wood debris Increasing Fire Increased fire risk Soil Organic content Generally low, high at river red gum forest/woodland Nutrient level General low, more information needed Exchange capacity High Water chemical Salinity Variable, can be very high in lakes due to evaporation Nutrient level High to very high in terms of phosphorus, especially in fresh inundated lakes and swamps pH Variable, can be low because of tannic acid Dissolved oxygen Variable, can be very low due to accumulated organic matter Biota Vegetation Majority in poor to very poor condition and communities declining Waterbirds Evidence of collapsed waterbird population and declining Fish Some species may locally extinct. Population of native fish is declining but more data and information are needed. Frogs Population size declining particularly for the endangered southern bell frog mainly due to habitat loses and fragmentation Other animals Maintained but some populations are decreasing Plant species Maintained either in living stands or seedbank, but more data and information are needed.

38 Description of wetland ecological character Data source: Childs (2009) Figure 17: Locations of the 23 wetlands listed in Table 13

Yanga National Park 39 ). Acacia Typha orientalis ). ). ). river red gum, black box, lignum and river cooba ( cooba river lignum and black box, gum, river red stenophylla river red gums. It is an important southern bell frog large and is filled by the et al. 2008a), (Wassens recruitment site River via the Mercedes regulator. Murrumbidgee vegetation community and is an important nesting site for colonial is an important nesting vegetation community and waterbird species. Waugorah Lake and River Paddock Swamp are natural are natural Swamp Paddock River and Lake Waugorah completely receive water after Shaw’s Swamp is depressions that cropping by Yanga Station. for filled and were once developed and never water stock and with domestic is filled Lake Waugorah dries. considered to be integral foraging sites for Both wetlands are Swamp. and North Stallion waterbirds nesting in Shaw’s Swamp that has maintained few wetlands within Lowbidgee one of This is passage connectivity to the river, and thus provides unimpeded spawn. for native fish to enter and forest with a macrophytic understorey that contains sparse beds beds sparse that contains understorey with a macrophytic forest cumbungi reed and of tall spike rush, common ( a and gum forest a river red comprises perimeter The wetland ( Paspalidium grass layer of warrego summer ground dense jubiflorum Large numbers of cormorants utilise the river red gums to roost, river red gums utilise the of cormorants Large numbers foraging observed commonly are egrets and herons and ducks, and its The structural diversity of the swamp on the swamp. of land birds. community a diverse support also margins Ecological significance 2008–09 2008–09 red gum river comprises of the wetland The vegetative structure linked with the Murrumbidgee Murrumbidgee Last flood^ Feeding channel Mercedes Swamp Volume (ML) 40 640 Murrumbidgee Murrumbidgee 2000–01 40 640 100 1600 150 Creek Waugorah 2400 2000–01 Top Creek including of vegetation types a diversity comprises swamp This 2005–06 species. waterbird site for colonial nesting an important This is Area (ha) # Name Swamp Shaw’s 200 Lake Waugorah 3200 River Paddock 60 Murrumbidgee Swamp 960 2005–06 Creek Waugorah a river red gum and tall spike rush of consists Swamp Shaw’s Lagoon Hoblers 2000–01 10 North Stallion Swamp 160 Murrumbidgee Top Creek Swamp Swamp Mercedes Permanently 75 563 Pococks Swamp Murrumbidgee 18 2008–09 207 Overflow from Swamp is dominated by tall spike rush and fringed Mercedes Table 13: Table 13: Yanga National Park Important wetlands within

40 Description of wetland ecological character Podiceps ) and an important nesting and feeding area for other and feeding nesting an important ) and Diverse vegetation community. community. Diverse vegetation Key southern bell frog recruitment site (Wassens et al. 2008a). 1990). waterbirds (Maher nesting Foraging area for colonial (Maher 1990, for waterbirds Important breeding and foraging area 2006). Large open water area when filled. (Maher 1990). waterbirds. Important feeding site for cristatus waterbirds, particularly cormorants. Ecological significance 2008–09 Yanga National Park. The main floodway where EWA enters 1999–2000 for great crested grebes ( breeding habitat An important 1999–2000 Waterbird forage sites. Last flood^ channel channel and/or Nimmie– (via Caira system and/or Tala Lake Uara Creek) Feeding channel and/or Nimmie– (via Caira system Tala Lake) Volume (ML) 300 2550 Yanga regulator regulator 500 Yanga 6000 300 2550 Overland flow 150 2004–05 species. site for colonial waterbird nesting an important This is 2288 Overland flow 200 2300 2004–05 Overland flow Key southern bell frog recruitment site (Wassens et al. 2008a). 2004–05 site waterbirds. Important foraging flow Overland 200 2400 1000 12,000 Overland flow 2004–05 banks constructed without size with The only site significant Area (ha) Name# Top Narockwell Swamp The Avenue (Two Bridges) and Piggery Lake Little Piggery Narkungerie Swamp River Smyths Breer Swamp 150 Breer Creek Swamp 500 1725 Overland flow Egret Swamp 6000 Tarwillie Swamp Overland flow Tala Swamp 150 2004–05 200 site. and foraging Important nesting, breeding 2004–05 1800 2400 800 Overland flow site. and foraging Important nesting, breeding Overland flow Devils Creek 15,200 Swamp Overland flow 2004–05 2004–05 site. and foraging Important nesting, breeding waterbird rookery. A major colonial

Yanga National Park 41 ) ) and ), and woodland bird Sericornis brunneus Sericornis ). Sminthopsis murina Sminthopsis . iving in the future. water Melonadryas cucullata Melonadryas Sminthopsis crassicaudata Sminthopsis fat-tailed dunnart ( ( redthroat the threatened including species robin ( and hooded Important waterbird habitat before it dried out in 2001. habitat before it dried Important waterbird site in Important fish habitat, a NSW fisheries stocking before it boost native fish population catchment to Murrumbidgee dried out in 2001. within However, flows are currently retained settlement. European the Lowbidgee FCID by a series of earthen block banks, and there has been no flow into Yanga National Park since the early 1990s. small for a diverse range of fauna, including Provides habitat ( dunnart the common as such mammals Historically receiving water in large floods (1 5–7 years). water Historically receiving since the early 1990s. No flow Floral diversity. Ecological significance g the long dry period and the probabilitylow of rece area received area received water in 1989– 90 Last flood^ Feeding channel Volume (ML) 403 4026 Yanga Lake 1989–90 Floral diversity. 2892 28,919 Creek Fiddlers <10% of the Area (ha) # ^ The^ majority of artificially wetlands inundated as the Lowbidgee has not received natural overbankwere since flows the 1990s Data source: Childs (2009) # Wetlands listed from north-east to south-west. * It is more appropriate to be managed as terrestrial ecosystemconsiderin Name Yanga Lake 1324 35,086 Fingerboard* Yanga Creek 1402 1999–2000 14,015 NSW. in western One of the largest lakes Uara Creek 1989–90 Yanga Nature Reserve* River before the Murrumbidgee of anabranch An important Condouple Creek*

42 Description of wetland ecological character Photo: J Kelleway

Figure 18: The early development of saltbush at Yanga Lake in 2007

Photo: J Kelleway

Figure 19: Tala Lake in 2007, showing dead river red gums caused by permanent inundation before it dried out in 2001

Yanga National Park 43 Photo: J Maguire, 2001 Photo: J Kelleway, 2007 Figure 20: Piggery Lake when inundated (left) and dry (right)

Photo: Li Wen/OEH, Devember 2007 Photo: Li Wen/OEH, April 2008 Figure 21: Two Bridges swamp before (left) and after (right) receiving environmental water allocation

Photo: Li Wen/OEH, December 2007 Photo: Li Wen/OEH, April 2008 Figure 22: Mercedes Swamp before (left) and after (right) receiving environmental water allocation

44 Description of wetland ecological character 5.1.2 Large woody debris

Woody debris refers to whole trees or piles of twigs and branches that are deposited on a floodplain (Figure 23) or in a river channel (Figure 24) during a flood. It has a number of important functions in the river–floodplain system, one of which is the provision of regeneration sites for floodplain forest species. Where woody debris is deposited, it creates an obstacle to river flow. Depressions are scoured upstream of the debris and then become filled with fine sediments creating a moist microsite suitable for the regeneration of riparian species such as river red gums. In addition, large amounts of fine sediment are deposited at the downstream end of the woody debris forming another type of microsite rich in trapped nutrients, organic matter and seeds. These slightly raised, semi-protected sites tend to support dense patches of riparian species seedlings as well as aquatic plants, such as common reed (Phragmites australis).

Woody debris in streams can also function directly as ‘nurse logs’ for the colonisation of certain aquatic species providing surfaces for organisms to attach to, shelter for breeding and protection against predators. In the lower Murrumbidgee River, which has muddy beds and banks, woody debris is particularly important as it is the only stable surface to which microscopic plants and animals can attach.

In the floodplain, falling trees and branches also provide microhabitats for terrestrial biota including amphibians, reptiles and woodland birds during the dry phase (Mac Nally et al. 2001; Tockner et al. 2006).

Photo: Li Wen/OEH

Figure 23: Piles of river red gum branches which provide habitat for amphibians, reptiles, birds and small mammals

Yanga National Park 45 Photo: H Smith/OEH Figure 24: A fallen tree in the Murrumbidgee River channel downstream from Redbank Weir providing a surface for algae, microscopic plants and animals

5.1.3 Fire

As a natural element, fire has not only helped shape the environment, it has also been one of the driving forces in the evolution of native fauna and flora in Australia generally (Abbott and Burrows 2003). Prior to 2005, controlled fires were set deliberately to increase the prevalence of grasses (for grazing) and clearing floodways (for irrigation) in Yanga (R Hampton 2008, pers. comm.). Although it is generally agreed that natural fire plays an important role in determining the diversity, distribution and abundance of flora and fauna in floodplain ecosystems, there is no information about the fire regime (type, frequency, season and intensity of a fire) in Yanga National Park.

5.2 Chemical components

5.2.1 Soil chemistry

In 2008 the Department of Environment and Climate Change (DECC) completed a detailed soil survey in Yanga National Park (EAS 2008). The following information is a summary of data collected by the Yanga Soil Survey project (Table 14), which sampled 13 sites in Yanga National Park (Figure 25).

Soil exchange capacity is high (generally greater than 30 meq/100 g) throughout the park, corresponding to the high soil clay content. The soil has a high ability to hold nutrients, minerals and water.

46 Description of wetland ecological character The top layer (0–30 cm) of soil has a generally low salinity level (EC1:5 <0.3 dS/m), except for one site on red soil with chenopod shrubland, which has an elevated EC level (EC1:5 >3.5 dS/m). However, soil salinity levels generally increase with depth. The top soil generally has a low sodicity value (exchangeable sodium percentage, ESP <5) except the chenopod shrubland site, which is strongly sodic. However, ESP generally increases with depth in two lakes (Yanga and Piggery) which have a relatively low value for the whole soil profile.

Soil pH varies from slightly acid (6.2< pH1:5 <6.7) to strongly alkaline (>8.5). The organic carbon is low (<1%) throughout the park, with a relatively higher value at river red gum forest/woodland.

5.2.2 Water quality

The NSW Department of Land and Water Conservation (DLWC) commenced a comprehensive valley-wide water quality monitoring program in the Murrumbidgee River in 1990, continued regularly at four key sites in Yanga National Park (Kneebone 1995). In addition, in 1998–2000 the catchment monitoring services of DLWC carried out a water quality and flow assessment program for the Redbank Irrigation District, which included nine addition field sites in Yanga National Park (Cawley 2000). After 2000, the majority of wetlands within the Yanga floodplain have been dry, and there has been no systemic water quality monitoring. The following description of selected water chemical parameters is summarised from the water quality and flow assessment program (Kneebone 1995; Cawley 2000).

Table 14: Soil chemistry characteristics in Yanga National Park, average values for a 1-m soil profile

Site1 CEC2 ESP3 EC pH OC4 Soil type and vegetation Ya02 48.3 8.4 0.3 9.29 0.73 Black box woodland on grey soil Ya03 35.2 7.4 0.2 7.30 0.90 River red gum forest on grey soil Ya04 44.2 13.1 0.9 6.73 0.90 River red gum forest on grey soil Ya11 36.1 7.1 0.2 7.62 0.90 River red gum forest on grey soil Ya13 39.5 0.9 1.0 7.06 0.90 River red gum woodland on grey soil Ya20 38.4 7.7 0.2 7.61 0.90 River red gum woodland on grey soil Ya21 26.3 3.7 0.1 8.71 0.73 Black box woodland on brown soil Ya27 28.6 8.9 0.3 6.29 0.90 River red gum woodland on grey soil Ya43 29.7 6.2 0.2 6.87 0.90 Lignum swamp on grey soil Ya54 38.8 13.3 0.3 8.44 0.90 River red gum woodland on brown soil Ya108 62.5 40.9 3.9 8.58 0.73 Chenopod shrubland on red soil Ya119 29.1 5.2 0.2 7.21 0.68 Piggery Lake Ya111 36.3 2.9 0.2 7.60 0.68 Yanga Lake

Data source: EAS (2008) 1 Refer to Figure 25 for site location; 2 CEC = exchange capacity (meq/100 g) 3 ESP = exchangeable sodium percentage (%) 4 OC = Organic carbon content (5%)

Yanga National Park 47 6205000

6200000 Ya04 Ya03 6195000

6190000 Ya119Ya11 Ya13 6185000

6180000 Ya43 Ya02 Ya54 6175000

6170000

Ya27 6165000

Ya108 Ya21 6160000 Ya20

Ya111 6155000

6150000

6145000

6140000

6135000

725000 730000 735000 740000 745000 750000 755000 760000 765000 770000 775000

Figure 25: Soil sampling sites at Yanga National Park

48 Description of wetland ecological character Generally, water quality in water bodies (swamps, creeks and canals, lakes and water storages) within the Yanga floodplain is affected by a range of factors. These factors include source water (the Murrumbidgee vs Nimmie–Caira FCID), distance from source water (travel time), physical features of the water body (open water vs vegetated) and flow path (channelled vs overland). Salinity level is generally low and within the ANZECC guidelines for freshwater ecosystems (ANZECC & ARMCANZ 2000). However, in lakes (such as Yanga Lake and Tala Lake) and isolated pools, salinity could exceed the guidelines due to condensation due to evaporation. Total phosphorus concentration (TP) in the Murrumbidgee River from Hay to Balranald is poor and exceeds the ANZECC lowland river trigger value of 50 μg/L (DLWC 1995). Once water enters the floodplain, TP concentration increases as it flows across the land, suggesting that phosphorus is being released from the topsoil. Because there is little relationship between TP and turbidity in the floodplain, the decay of litter and vegetation is thought to be the main contributor. Total nitrogen concentration was not measured in the DLWC programs. In a study to investigate the pollution sources in the lower Murrumbidgee River, the State Pollution Control Commission had a sampling site at the centre of the Murrumbidgee River at Balranald Pumping Station No 2 (SPCC 1976). The results indicated that the nitrogen concentration was very low (50–110 μg/L) compared to the ANZECC guideline of 500 μg/L. pH is generally neutral to slightly alkaline in the river channel and most of the time is within ANZECC guidelines. In the floodplain, pH is lower (less alkaline) reflecting the influence of tannic acid and the breakdown of plant materials. Dissolved oxygen (DO) concentrations should be 80–120% for lowland rivers and 90– 120% for freshwater wetlands according to the ANZECC guidelines (ANZECC & ARMCANZ 2000). Water in the Murrumbidgee River at Redbank and Balranald Weir was assessed as poor (DO concentration 20–80%) (DLWC 1995) and variable (Cawley 2000). However, DO levels in the Murrumbidgee channel were more consistent and within the ANZECC guidelines at most times. In the floodplain waters, DO levels were generally lower than the 90% saturation threshold, except in larger open waters (such as Yanga Lake and Tala Lake). The lower DO level was possibly due to bacterial oxygen demand to break down accumulated organic matter. Turbidity at Redbank and Balranald weirs was normally within the ANZECC guidelines (6–50 NTU). In Lake Yanga and Tala Lake, turbidity was much higher than in other waters due to wind mixing and lake-bed load. In other shallow swamps, turbidity was low and normally under 100 NTU. In irrigation canals, flowing water could be very turbid. Tannic acid, which gives water a dark brown colour, is a polyphenol and is present in trees like river red gum and black box. The concentration of tannic acid is low in the Murrumbidgee (0.2 mg/L: Cawley 2000). When water enters the floodplain and comes into contact with litter, tannin is released and the tannic acid concentration increases. Because of its relatively stable chemical structure, the concentrations appear to be cumulative in the short term (they tend to continuously increase with increased exposure to litter); thus, the receiving waters in the drainage basins normally have greater concentrations. In Yanga Lake and Tala Lake, however, tannic acid concentrations were lower than in the source waters suggesting the breakdown of tannin under conditions associated with the lakes (very long residence time, high turbidity, alkaline).

Yanga National Park 49 5.3 Biological component of Yanga National Park

5.3.1 Important plant communities

The assemblages of plant species that often grow at the same location are known as plant communities. The distribution of different plant communities across landscapes is influenced by various factors, such as climate, position in the landscape, biological interactions and site history (for example bushfires, floods, human activities such as land clearing and logging).

Scott (1992) mapped nine communities in Yanga National Park. A rapid field inspection in 2005 by NPWS revealed a further three localised vegetation types (Benson et al. 2006). In 2008, DECC committed a project to map the historic vegetation extent and condition in Yanga National Park which identified 17 vegetation classes from five formation groups (McCosker 2008) (Table 15). The distribution of vegetation communities in Yanga National Park at 2005 is shown in Figure 26.

The boundaries of major plant communities remain relatively unchanged from the 1960s (McCosker 2008). However, the canopy cover and condition for each community are generally poor to very poor, with the exception of small areas receiving regular controlled flooding (irrigation), which are in good condition (Table 15). These areas include Two Bridge Swamp and surrounds, Shaw’s Swamp and surrounds, and Waugorah Creek and Pee Vee Creek (McCosker 2008).

Of the 17 vegetation types in McCosker (2008), river red gum forest/woodland, black box woodland, lignum/nitre goosefoot (Chenopodium nitrariaceum) shrubland, and spike rush (Eleocharis spp.) dominated sedgeland are identified as important and described in detail here.

River red gum community

River red gum forest/woodland occurs along rivers, creeks, levees and adjacent flats, channelled plains and other areas subject to frequent or periodic flooding. It is usually on heavy grey, brown and red clays (Porteners 1993).

In Yanga National Park there are over 22,000 ha of river red gum forests/woodlands which cover the majority of the section north of Yanga Lake (Figures 24 and 25). The community was further classified into four sub-classes by Benson et al. (2006) and McCosker (2008): river red gum tall gallery forest (1083 ha) which lines the main channel of the Murrumbidgee, including levees river red gum forest with a dense sedge understorey dominated by common spike rush (Eleocharis acuta) (4622 ha) which occurs on flats of black, self-mulching clay and the bed of intermittent lakes river red gum woodland with grassy understorey (3689 ha) river red gum forest with a shrubby lignum understorey (11,926 ha).

50 Description of wetland ecological character Data source: McCosker (2008), based on 2005 aerial photography

Figure 26: Vegetation distribution in Yanga National Park

Yanga National Park 51 Table 15: Plant communities found within Yanga National Park Area Formation Class Characteristic species Structure Condition+ Threat * (ha)^ Acacia Yarran Acacia melvillei; Eremophila sturtii; Open Fair – poor 1 and 5 Woodlands shrubland Enchylaena tomentosa; shrubland 720 and Dissocarpus paradoxus; Shrublands of Sclerolaena obliquicuspis the Inland Prickly wattle Acacia victoriae subsp. arida; Open Poor 5, 3, 7 Slopes and shrubland Dodonaea viscosa subsp. shrubland 14 Plains angustissima; Enchylaena tomentosa; Dissocarpus paradoxus Chenopod Black Maireana pyramidata; Rhagodia Open/sparse Poor – 1 and 5 (Halophytic) bluebush low spinescens; Maireana georgei; chenopod very poor Shrublands of open Atriplex vesicaria sens lat.; shrubland the Inland shrubland Scleroleana obliquicuspis; Enchylaena tomentosa; Austrostipa nitida; Calotis hispidula Pearl Maireana sedifolia; Maireana Open/sparse 5 5086 bluebush low pyramidata; Atriplex vesicaria sens chenopod open lat.; Maireana sclerolaenoides; shrubland shrubland Enchylaena tomentosa; Sclerolaena obliquicuspis; Sclerolaena patenticuspis; Austrostipa nitida Bladder Atriplex vesicaria sens lat.; Open Poor 1, 5, 9, saltbush Pachycornia triandra; Sclerostegia chenopod 10 shrubland tricuspis; Disphyma crassifolium shrubland subsp. clavellatum; Sclerolaena brachyptera; Dissocarpus biflorus var. biflorus; Chloris truncata Old man Atriplex nummularia; Rhagodia Open/sparse 5, 1, 6, 32 saltbush spinescens; Maireana microcarpa; chenopod 8,4 shrubland M. pyramidata; A. vesicaria sens shrubland lat.; Dissocarpus biflorus; Osteocarpum acropterum var. acropterum; A. lindleyi; Chloris truncata Nitre Chenopodium nitrariaceum; Open Poor – 1, 9, 2, goosefoot Sclerolaena muricata sens lat.; chenopod very poor 4, 5 shrubland S.stelligera; Malacocera tricornis shrubland Cotton bush Maireana aphylla; Sclerolaena Open/sparse 2, 5, 8, 9 6064 open tricuspis; Calocephalus sonderi; chenopod shrubland Rhodanthe corymbiflora; shrubland Austrodanthonia caespitosa Dillon bush Nitraria billardierei; Rhagodia Sparse Poor – 8, 5, 6 shrubland spinescens; Sclerolaena tricuspis; chenopod very poor 13,521 Austrostipa scabra subsp. scabra shrubland Cypress Pine Slender Callitris gracilis subsp. murrayensis; Open Poor 1, 3, 8, 6 (Callitris) cypress pine – Myoporum platycarpum subsp. woodland, Woodlands sugarwood – platycarpum; Alectryon oleifolius isolated Mainly of the western subsp. canescens; Dodonaea trees 4827 Inland rosewood viscosa subsp. angustissima; open Maireana pentagona; Sclerolaena woodland obliquicuspis; Zygophyllum apiculatum; Austrostipa nodosa

52 Description of wetland ecological character + * Area Formation Class Characteristic species Structure Condition Threat ^ (ha) Eucalyptus River red gum Eucalyptus camaldulensis subsp. Open forest Good – fair 4, 3, 2, Communities riparian open camaldulensis; Eleocharis acuta- 5, 6 of Inland forest Centipeda cunninghamii- 1083 Watercourses Ranunculus inundatus- and Inner Pseudoraphis spinescens Floodplains River red gum Eucalyptus camaldulensis subsp. Open forest Poor – 4, 3, 2, woodland with camaldulensis; Eleocharis acuta, very poor, 5, 6 sedge Paspalidium jubiflorum; small 4622 groundcover Wahlenbergia fluminalis; Senecio stands in quadridentatus; Carex tereticaulis good condition River red gum Eucalyptus camaldulensis subsp. Woodland Poor – 4, 1, 2, woodland with camaldulensis; Austrodanthonia very poor, 3, 5, 6 3689 grass caespitosa; Juncus flavidus; Carex dead tree groundcover inversa stands River red gum Eucalyptus camaldulensis subsp. Open forest Poor – 4, 1, 2, forest with camaldulensis; Acacia stenophylla; woodland very poor, 3, 5, 6 shrubby Muehlenbeckia florulenta; dead tree 11,926 understorey Paspalidium jubiflorum; Cyperus stands gymnocaulos; Einadia nutans subsp. nutans Black box - Eucalyptus largiflorens; Woodland, Poor – 1, 2, 4, lignum Muehlenbeckia florulenta; open very poor 5, 6 woodland Chenopodium nitrariaceum; woodland Einadia nutans subsp. nutans; 3020 Paspalidium jubiflorum; Sclerolaena muricata var. muricata; Austrodanthonia caespitosa Black box Eucalyptus largiflorens; Open Poor – 1, 2, 4, 9044 open wood- Chenopodium nitrariaceum; woodland, very poor, 5, 6 land with Maireana pyramidata; Einadia woodland dead tree chenopod nutans subsp. nutans; Sclerolaena stands understorey divaricata; Atriplex semibaccata Freshwater Shallow Eleocharis acuta; Pseudoraphis Forbland Poor – 4, 5, 6 650 Wetlands: marsh of spinescens; Persicaria hydropiper; very poor, Inland regularly Lachnagrostis filiformis; Ludwigia some Aquatic, flooded peploides subsp. montevidensis; areas Swamp and depressions Myriophyllum crispatum excellent Shrubland Lignum Muehlenbeckia florulenta; Open Very poor 1, 2, 4, 5 1336 Communities shrubland of Chenopodium nitrariaceum; shrubland, the semi-arid Sclerolaena tricuspis; Senecio chenopod (warm) plains cunninghamii var. cunninghamii; shrubland Einadia nutans subsp. nutans Permanent Eleocharis sphacelata; Forbland, Poor – 1, 2, 4, 1900 and semi- Bolboschoenus medianus; Carex open very poor, 7, 8, 6 permanent fascicularis; Lemna disperma; forbland, some freshwater Azolla filiculoides; Myriophyllum open areas lakes crispatum; Potamogeton sedgeland excellent tricarinatus Data sources: Benson et al. (2006); McCosker (2008) + Based on field assessment made in 2007 and 2008 * 1 = Land clearing, 2 = Cropping; 3 = Logging; 4 = Hydrology disruption; 5 = Grazing; 6 = Introduced species; 7 = Eutrophication; 8 = Erosion; 9= disease; 10 = Fire. ^ McCosker’s (2008) vegetation mapping based on 2005 aerial photography. In the vegetation map, one class – scald areas with scattered blue bush, dillon bush grassland (5086 ha) – was not included.

Yanga National Park 53 The majority of river red gum communities are severely stressed except the small areas of riparian forest lining the Murrumbidgee River and Pee Vee Creek, which deliver irrigation water to Tala Lake, and other patches which have been regularly irrigated. The stands of river red gum in good condition are general located along the floodway from Yanga regulator to upstream of Piggery Lake. Downstream of Piggery Lake to upstream of Yanga Lake the communities are either severely stressed or dead (Figure 27).

Black box woodland

Black box woodland typically occurs on the less frequently flooded areas of the floodplain above the level of the adjacent river red gum forest. The understorey of the black box woodlands is variable and may include nitre goosefoot, thorny saltbush (Rhagodia spinescens), old man saltbush and lignum.

The extent of black box woodland has remained constant at about 12,000 ha since 1965 (McCosker 2008). However, black box in most areas displayed symptoms of stress, with bare branches (dieback) and epicormic shoots evident. The patches of dead mature cooba in black box woodland is not uncommon throughout Yanga National Park.

Lignum/nitre goosefoot shrubland

Lignum forms a kind of shrubland adjacent to major creeks and rivers and in low-lying swampy areas on heavy grey cracking clays (Porteners 1993). It can withstand infrequent but prolonged flooding and can form dense, almost impenetrable, stands (Porteners 1993; Cunningham et al. 1981). It commonly occurs on channelled plains and depressions with impeded drainage and is often associated with river red gum and black box as an understorey (Figure 28).

Lignum swamps that have been subject to regular inundation become dense and tall and are favoured breeding sites for many waterbird species (Figure 29). These types of lignum swamp are quite rare and the lignum swamps around the Lowbidgee floodplains were identified in 1990 as supporting the best stands in NSW and possibly eastern Australia (Maher 1990). Nitre goosefoot is co-dominant with lignum in some locations with an inconsistent ground cover, depending on flooding history.

There are currently around 7000 ha lignum/nitre goosefoot shrublands in Yanga National Park. Their condition has deteriorated over the 40 years of sampling (1965– 2005) (McCosker 2008).

Spike rush dominated sedgeland

This general term covers many shallow low-lying areas scattered throughout the better- watered parts of the floodplain. Under a natural flow regime, these areas are subjected to irregular but frequent (once every 2–3 years) inundation (Maher 1990), but regularly refilled by divisions via Yanga regulator and Waugorah regulator after gazettal as the Lowbidgee FCID in 1944. They are generally small, ranging in size from less than one to several hundreds of hectares, and have different geomorphic histories.

In Yanga National Park, these areas are generally dominated by common spike-rush and occasionally cohabit with tall spike-rush (E. sphacelata) in standing water or recently wet areas. Associated water plants include common nardoo (Marsilea drummondii), smooth nardoo (Marsilea mutica), water milfoils (Myriophyllum spp.), wavy marshwort (Nymphoides crenata), water couch (Paspalum distichium), common joyweed (Alternanthera nodiflora) and buttercups (Ranunculus spp.); lagoon saltbush

54 Description of wetland ecological character (Atriplex suberecta) and black rolypoly (Sclerolaena muricata subsp. muricata) grow in wetland margins. Common reed is regenerating in places, particularly where it is protected from grazing by fallen logs and windrows left by logging operations.

Data source: McCosker (2008)

Figure 27: Condition of river red gums in 2005 based on aerial photography

Yanga National Park 55 Photo: J Maguire/OEH, 2005 Figure 28: Lignum swamp at the Fingerboards in Lowbidgee with black box in the background

Photo: J Maguire/OEH, 2005 Figure 29: Lignum swamps, which provide important waterbird breeding habitat in the Lowbidgee floodplain

56 Description of wetland ecological character 5.3.2 Waterbirds

A number of bird surveys have been undertaken in the region which includes part of Yanga National Park (Pressey et al. 1984; Maher 1990, 2006; Magrath 1992; Bales 1999; Kingsford and Porter 2006; Spencer and Allman 2008). A summary of these surveys is presented in Table 16.

Pressey et al. (1984) identified 114 bird species. They noted that the range of birds observed was generally similar to what had been recorded by a number of observers in 1923, 1940 and 1961. However, they also noted that a number of ground-living birds, notably the plains wanderer (Pedionomus torquatus), southern stone-curlew (Burhinus grallarius), Australian bustard (Ardeotis australis) and the brolga (Grus rubicunda), had either declined or become locally extinct. They attributed this to the effect of feral animals or grazing practices. They also suggested that, at the time of the survey, the number of wetland species observed may have been depressed by the dry conditions, and the number of honeyeater species by the lack of flowering trees.

Maher (1990) recorded a total of 164 species of birds during his survey. These consisted of 61 species which were classified as waterbirds and 103 which were land birds. Sixteen of the waterbirds were colonial nesting species. Results were presented for the habitat preference of the birds. River red gum forested wetlands, in conjunction with adjacent reed or rush dominated swamps, were identified as the most important habitat for waterbird breeding. Of 42 species found in the river red gum forest 30 were confirmed as breeding and this habitat was the main breeding habitat for 11 of the colonial nesting bird species. The presence of the reed/rush habitat within a reasonable proximity to the colonial nesting sites was considered important in providing feeding grounds.

The highest number of waterbirds were found in shallow marsh/reed/rush habitats (Maher 1990). A total of 53 waterbird species were observed, of which 17 were confirmed as breeding. The second most popular habitat for waterbirds was found to be lignum/nitre goosefoot dominated swamps where 50 species were observed, 21 of which were breeding. The lowest number of waterbirds, 36, of which 10 were breeding, were observed in black box swamps. Open water was an important breeding ground for a small number of species, in particular gull-billed terns (Gelochelidon nilotica) and silver gulls (Chroicocephalus novaehollandiae), but was more important as a major feeding area particularly as floodwaters receded. Flooded cropland was considered to provide an important feeding ground but provided little benefit for breeding purposes.

Magrath (1992) undertook a study specifically of waterbirds of the lower Lachlan and Murrumbidgee valleys. This study included three wetland areas within Yanga National Park, namely Redbank Swamp (including Mercedes and Pococks swamps), Tarwillie Swamp, and Egret Swamp. Redbank Swamp, a river red gum dominated swamp, was found to support sizeable populations of a number of waterbirds, including three egret and two cormorant species, and rufous (nankeen) night heron (Nycticorax caledonicus). It was suggested that the swamp was inundated annually and could support colonies in most years. Tarwillie Swamp was found to have supported one of the largest great egret colonies recorded in Australia. Large colonies of egrets and cormorants were observed on Egret Swamp.

A total of 64 waterbird species from 14 families were recorded by these surveys (Table 17).

Yanga National Park 57 Table 16: Major bird surveys in Lowbidgee region which have sites in Yanga National Park Total Waterbird Year Location Reference Comments species species 1982 Lowbidgee–Lachlan 114 42 Pressey et al. Severe drought in confluence (1984) 1982–83 1989–90 Lowbidgee–Lachlan 164 61 Maher (1990) Major flood during 1989 confluence resulting in breeding 1990–91 Lower Lachlan and ? Magrath This survey was Murrumbidgee (1992) specifically for valleys waterbirds. Major flood occurred during sampling period 1998–99 Redbank District 142 44 Bales (1999) Recorded 15 species that had not been recorded in previous surveys 1983– Lowbidgee floodplain 54 Kingsford and Total species detected 2008 Thomas in the annual aerial (2001) survey 2005– Yanga National Park 36 Maher (2006) Following the release 2006 of large volume of EWA. Twelve colonial nesting species were recorded breeding 2008 Lowbidgee 27 Spencer and RERP ecological Allman (2008) investigation. The majority of the park was dry; a few sites received EWA.

Table 17: Waterbird species recorded in Yanga National Park and surrounding floodplains

Family Common name Scientific name Accipitridae Swamp harrier Circus approximans White-bellied sea eagle Haliaeetus leucogaster Whistling kite Haliastur sphenurus Anatidae Chestnut teal Anas castanea Grey teal Anas gracilis Australasian shoveler Anas rhynchotis Pacific black duck Anas superciliosa Hardhead Aythya australis Musk duck Biziura lobata Australian wood duck Chenonetta jubata Black swan Cygnus atratus Plumed whistling duck Dendrocygna eytoni Pink-eared duck Malacorhynchus membranaceus Blue-billed duck Oxyura australis Freckled duck Stictonetta naevosa Australian shelduck Tadorna tadornoides Anhingidae Darter Anhinga melanogaster Ardeidae Great egret Ardea alba

58 Description of wetland ecological character Family Common name Scientific name Little egret Ardea garzetta Cattle egret Ardea ibis Intermediate egret Ardea intermedia White-faced heron Ardea novaehollandiae Pacific heron Ardea pacifica Australasian bittern Botaurus poiciloptilus Little bittern Ixobrychus minutus Rufous night heron Nycticorax caledonicus Charadriidae Black-fronted plover Charadrius melanops Red-fneed dotterel Erthrogonys cintus Masked lapwing Vanellus miles Banded lapwing Vanellus tricolor Laridae Caspian tern Hydroprogne caspia Silver gull Larus novaehollandiae Whiskered tern Sterna hybrida Gull-billed tern Sterna nilotica Pelecanidae Australian pelican Pelecanus conspicillatus Phalacrocoracidae Great cormorant Phalacrocorax carbo Little pied cormorant Phalacrocorax melanoleucos Little black cormorant Phalacrocorax sulcirostris Pied cormorant Phalacrocorax varius Podicipedidae Great-crested grebe Podiceps cristatus Hoary-headed grebe Poliocephalus poliocephalus Australasian grebe Tachybaptus novaehollandiae Rallidae Eurasian coot Fulica atra Dusky moorhen Gallinula tenebrosa Black-tailed native-hen Gallinula ventralis Purple swamphen Porphyrio porphyrio Australian crake Porzana fluminea Baillon’s crake Porzana pusilla Spotless crake Porzana tabuensis Buff-banded rail Rallus philippensis Recurvirostridae Banded stilt Cladorhynchus leucocephalus Black-winged stilt Himantopus himantopus Red-necked avocet Recurvirostris novaehollandiae Rostratulidae Painted snipe Rostratula benghalensis Scolopacidae Sharp-tailed sandpiper Calidris acuminate Latham's snipe Gallinago hardwickii Black-tailed godwit Limosa limosa Greenshank Tringa nebularia Marsh sandpiper Tringa stagnatilis Threskiornithidae Yellow-billed spoonbill Platalea flavipes Royal spoonbill Platalea regia Glossy ibis Plegadis falcinellus Australian white (sacred) ibis Threskiornis aethiopica Straw-necked ibis Threskiornis spinicollis Data sources: Pressey et al. (1984); Maher (1990, 2006); Magrath (1992); Bales (1999); Kingsford and Thomas (2001); Spencer and Allman (2008)

Yanga National Park 59 5.3.3 Fish

Very little systematic work has been undertaken on the fish in Yanga National Park or surrounding wetlands. Fish were not included in the studies undertaken by Pressey et al. (1984) or Robertson et al. (1994). Maher (1990), whilst predominantly reporting on birds of the Lachlan–Murrumbidgee confluence, referred to fish which were observed during the study. These were European carp (Cyprinus carpio), bony bream (Nematalosa eribi) and mosquito fish (Gambusia affinis). The carp were said to be abundant in all swamps, particularly those used as water storages and in the Lachlan and Murrumbidgee rivers. Bony bream were observed in large numbers in Tala Creek during a period of rising floodwater. Mosquito fish were observed to be common in shallow floodwater (Maher 1990).

A number of fish surveys have been conducted in the Murrumbidgee catchment by NSW Fisheries (cf. Baumgartner 2004; Gilligan 2005). These studies focused on instream habitats and did not include any sites on the Lowbidgee floodplain. Therefore these studies provide little information about fish usage of floodplain habitats.

Bales (1999) sampled a range of fish habitats in Yanga National Park, including small and large irrigation channels, lakes and deep waters, and shallow wetlands. Eight species were recorded; however, the fish community was dominated by introduced species, notably European carp, in all habitats. In addition, two hardy freshwater species – yabby (Cheerax destructor) and long-necked turtle (Chelodina longicollis) – were also abundant in these habitats except the lakes.

As part of the RERP ecological investigation, Spencer and Allman (2008) sampled nine sites (four in Yanga National Park) in the spring breeding season in Lowbidgee including irrigation channels, temporary wetlands, water storages and the Murrumbidgee channel. A total of 12 species (eight native and four introduced) were recorded. Again, the introduced European carp dominated most of the sampled sites.

Table 18 lists all fish species known to occur in Yanga National Park (including the Murrumbidgee channel).

5.3.4 Frogs

Limited historical information is available on frogs in Yanga National Park. Pressey et al. (1984) recorded four species for the Lachlan–Murrumbidgee confluence area: brown froglet (Crinia parinsignifera), spotted-marsh frog (Limnodynastes tasmaniensis), barking marsh frog (Limnodynastes fletcheri) and Peron’s tree frog (Litoria peronii). Based upon knowledge about the general distribution of frog species Pressey et al. (1984) predicted that a further seven species could be expected to occur within the area.

Maher (1990) also recorded a number of frog species. Peron’s tree frog, barking marsh frog and spotted-marsh frog were all recorded in the Redbank Weir area. One individual of the southern bell frog was also recorded in this area.

Robertson et al. (1994), in their study of the Nimmie–Caira system, reported that frogs were abundant at many of the wetter sites investigated. Five species were described as being ‘detected too numerous to tabulate’. These include two species of brown froglet (Crinia signifera, C. parasignifera), spotted marsh frog, barking marsh frog and Peron’s tree frog. A number of southern bell frogs were also located by the authors following extensive searching.

60 Description of wetland ecological character Table 18: Fish species in the Lowbidgee region, including the Murrumbidgee channel

Family Scientific name Common name Clupeidae Nematalosa erebi Bony bream Galaxiidae Galaxias brevipinnis ^ Climbing galaxias Retropinnidae Retropinna semoni Australian smelt Plotosidae Tandanus tandanus + Freshwater catfish Atherinidae Craterocephalus fluviatilis + Murray hardyhead Craterocephalus stercusmuscarum fulvus Unspecked hardyhead Melanotaeniidae Melanotaenia fluviatilis + Murray–Darling rainbowfish Percichthyidae Macquaria ambigua ambigua Golden perch Maccullochella peelii peelii + Murray cod Terapontidae Bidyanus bidyanus Silver perch Leiopotherapon unicolor Spangled perch Eleotridae Philypnodon grandiceps Flat-headed gudgeon Hypseleotris spp Western carp gudgeon Cyprinidae Cyprinus carpio * Carp Carassius auratus * Goldfish Cobitidae Misgurnus anguillicaudatus * Oriental weatherloach Poecilidae Gambusia holbrooki* Eastern gambusia Percidae Perca fluviatilis * Redfin perch * Exotic species, + Likely to be locally extinct., ^ trans-located native species. Data sources: Bales (1999); Baumgartner (2004); Gilligan (2005); Spencer and Allman (2008)

Bales (1999) recorded 10 species in Yanga National Park. Brown froglet (Crinia sloanei), eastern pobblebonk (Limnodynastes dumerilii), painted burrowing frog (Neobatrachus sudelli) and desert tree frog (Litoria rubella) were not reported by the above surveys.

Although targeting the endangered southern bell frog, Wassens et al. (2008a) recently recorded six frog species in Yanga National Park; the giant banjo frog (Limnodynastes interioris) has not been reported before.

A search of the Atlas of NSW Wildlife for Yanga National Park produced a record of eight frog species. Collating all the records, a total of 12 species from three families has been recorded in Yanga National Park (Table 19).

The southern bell frog was once widespread and abundant throughout south-eastern Australia (Wassens et al. 2008b). Since the early 1980s its population and distribution have been reduced to a critical level (Lunney et al. 2000) and, for this reason, it is listed as endangered on the schedules of the TSC Act.

In the Lowbidgee, the southern bell frog occupies two different habitats: river red gum forest and black box/lignum woodland (Bales 1999; Wassens 2008b). In river red gum swamps in Yanga National Park the species is associated with emergent macrophytes such as tall spike rush (Eleocharis sphacelata) and water primrose (Ludwigia peploides). In contrast, the black box/lignum wetlands within the Nimmie–Caira system contain abundant floating and submerged macrophytes such as nardoo (Marsilea drummondii) and common milfoil (Myriophyllum variifolium) (Wassens et al. 2008a). As there is no long-term monitoring data, it is not clear exactly when southern bell frog populations began to decline within the Lowbidgee. However, like many amphibians, the southern bell frog is thought to be particularly vulnerable to habitat loss and fragmentation (Wassens et al. 2008b).

Yanga National Park 61 5.3.5 Reptiles

Only limited studies have been undertaken that cover the reptiles of Yanga National Park. Pressey et al. (1984) recorded reptiles as part of their survey of the wetlands of the Lachlan–Murrumbidgee confluence. As part of a flora and fauna survey for Redbank Riparian Landcare group, Bales (1999) targeted likely habitats such as tree hollows, under logs, woody debris and tree bark. Eighteen species, including four geckos, two goannas, two dragons, five skinks, two snakes and two turtles, were sampled in this survey.

Combining all records including those in the Atlas of NSW Wildlife, a total of 24 reptile species have been recorded as occurring in Yanga National Park and its surroundings (Table 20).

5.3.6 Mammals

Information for mammals in Yanga National Park is scattered and limited. Some information is available from a number of studies which have been undertaken on the wetlands of the Murrumbidgee–Lachlan confluence. These include Pressey et al. (1984) and Robertson et al. (1994). Mammals were included in the Redbank flora and fauna survey by Bales (1999). Recently, a total of 11 bat species was recorded in a bat survey in Yanga National Park (M Pennay 2009, pers. comm.). Table 21 presents a list of 33 (seven introduced) mammal species that were recorded in these surveys and species recorded in the Atlas of NSW Wildlife.

Table 19: Frog species in Yanga National Park and surrounding floodplains

Family Scientific name Common name Reference Myobatrachidae Crinia parinsignifera Eastern sign-bearing froglet 1, 3, 4, 5, 6 Crinia signifera Common eastern froglet 3, 4, 5 Crinia sloanei Sloane's froglet 4 Limnodynastes dumerilii Eastern banjo frog 4, 5 Limnodynastes fletcheri Long-thumbed frog 1, 2, 3, 4, 5, 6 Limnodynastes interioris Giant banjo frog 6 Limnodynastes tasmaniensis Spotted grass frog 1, 2, 3, 4, 5, 6 Pseudophryne bibronii Bibron's toadlet 5 Neobatrachus Neobatrachus sudelli Burrowing frog 4, Hylidae Litoria peronii Peron's tree frog 1, 2, 3, 4, 5, 6 Litoria raniformis Southern bell frog 2, 3, 4, 5, 6 Litoria rubella Desert tree frog 4

Data sources: 1: Pressey et al. (1984); 2: Maher (1990); 3: Robertson et al. (1994); 4: Bales (1999); 5: Atlas of NSW Wildlife; 6: Wassens et al. (2008a)

62 Description of wetland ecological character Table 20: Reptiles recorded in Yanga National Park and surrounding floodplains

Family Scientific name Common name Pygopodidae Aprasia inaurita Mallee worm lizard Chelidae Chelodina longicollis Eastern long-necked turtle Emydura macquarii Murray turtle Gekkonidae Christinus marmoratus Marbled gecko Diplodactylus tessellatus Tessellated gecko Underwoodisaurus milii Thick-tailed gecko Gehyra variegata Tree dtella Strophurus intermedius Southern spiny-tailed gecko Agamidae Pogona barbata Bearded dragon Pogona vitticeps Central bearded dragon Varanidae Varanus gouldii Gould's goanna Varanus varius Lace monitor Scincidae Ctenotus atlas Southern mallee ctenotus Cryptoblepharus carnabyi Spiny-palmed shinning-skink Egernia striolata Tree skink Lerista muelleri Wood mulch-slider Lerista punctatovittata Eastern robust slider Morethia boulengeri South-eastern morethia skink Tiliqua rugosa Shingle-back Elapidae Echiopsis curta Bardick Notechis scutatus Tiger snake Pseudechis porphyriacus Red-bellied black snake Pseudonaja textilis Eastern brown snake Suta suta Curl snake

Data sources: Pressey et al. (1984); Maher (1990); Bales (1999); Atlas of NSW Wildlife

Yanga National Park 63 Table 21: Mammal species in Yanga National Park and surroundings

Family Scientific name Common name Canidae Vulpes vulpes * European red fox Cervidae Cervus elaphus * Red deer Dasyuridae Dasyurus maculatus Spotted-tailed quoll Sminthopsis crassicaudata Fat-tailed dunnart Sminthopsis murina Common dunnart Felidae Felis catus * Feral cat Leporidae Lepus capensis * Brown hare Oryctolagus cuniculus * Rabbit Macropodidae Macropus fuliginosus Western grey kangaroo Macropus giganteus Eastern grey kangaroo Macropus rufus Red kangaroo Molossidae Mormopterus planiceps Little mastiff-bat Muridae Hydromys chrysogaster Water-rat Mus musculus * House mouse Notomys mitchellii Mitchell's hopping-mouse Peramelidae Chaeropus ecaudatus Pig-footed bandicoot Phalangeridae Trichosurus sp. Brushtail possum Trichosurus vulpecula Common brushtail possum Suidae Sus scrofa * Feral pig Tachyglossidae Tachyglossus aculeatus Short-beaked echidna Vespertilionidae Chalinolobus gouldii Gould's wattled bat Chalinolobus morio Chocolate wattled bat Nyctophilus geoffroyi Lesser long-eared bat Nyctophilus gouldi Gould’s long-eared bat Scotorepens balstoni Inland broad-nosed bat Myotis Macropus Large-footed myotis (fishing bat) Eptesicus vulturnus Small forest eptesicus Vespadelus darlingtoni Large forest bat Vespadelus regulus Southern forest bat Vespadelus vulturnus Little forest bat Molossidae Mormopterus ridei Eastern freetail bat Mormopterus ‘species 4’ Southern freetail bat Austronomus australis White-striped freetail bat

Data sources: Pressey et al. (1984); Robertson et al. (1994); Bales (1999); Atlas of NSW Wildlife, M Pennay (2009, pers. comm.) * Introduced species

64 Description of wetland ecological character 6 Critical ecosystem processes

Ecosystem processes are the physical, chemical and biological actions or events that link organisms and their environment. They include decomposition, production, nutrient cycling and fluxes of nutrients and energy (MEA 2005). Rather than describing all ecosystem processes (an impractical task), this section will focus on those critical processes that most strongly influence or determine the ecological character of Yanga National Park, in particular hydrological and geomorphologic processes.

6.1 Hydrological processes

The ‘flood pulse’, a term used for the floodwater input to floodplains, is commonly perceived as the main factor that controls the existence and productivity of floodplain ecosystems of major world rivers (Junk et al. 1989; Junk 1997; Lewis et al. 2000). In the Lowbidgee, where evaporation greatly exceeds rainfall, floodwater is vital to sustain functioning ecosystems in the floodplain, and the inundation regime (extent, frequency, duration and timing) is the governing process for other critical processes (Figure 30).

In Yanga National Park the natural inundation regime is primarily governed by flow in the Murrumbidgee River. However, the construction of Redbank and Maude weirs in 1939 and the subsequent introduction of the Lowbidgee FCID in the 1940s greatly modified the distribution and retention of water within the floodplain resulting in smaller inundated areas with longer residence time (Table 22).

6.1.1 Natural overbank flows

Yanga National Park experiences natural flooding during high flows. Kingsford and Thomas (2001) provided a detailed description of how overbank flows disperse in the Lowbidgee floodplain, as cited below.

Overbank flows are distributed throughout the floodplain by a series of distributaries (Fiddlers, Uara, Caira, Nimmie, Pollen, Waugorah, Talpee, Monkem, Kietta, Yanga, Paika and other unnamed small creeks), which form a highly complex interconnected network of braided creeks on the Lower Murrumbidgee floodplain. Most of these convey water to the south but some small creeks also take water to the north where the Lachlan River terminates in the Great Cumbung Swamp. Flows from the Lachlan River rarely reach the Murrumbidgee River except in major floods. Flows leave the Murrumbidgee River first at Fiddlers Creek (previously known as Gum Creek). This creek system is shallow and provided water to the south. The floodplain of this creek system includes Yanga Nature Reserve (1772 ha), an area recognised for its stands of Black Box woodland. Anastomosing channels of Fiddlers Creek eventually form the Uara Creek that forms a channel and conveys water to Yanga Lake and the Murrumbidgee River near the town of Balranald. The next creeks to leave the Murrumbidgee River are the Caira and Nimmie Creeks that also convey water to the southwest. Neither has well defined channels from the river. The river used to flow over the banks to these systems of anastomosing channels. Water from the Caira Creek flowed south before bifurcating to the north to form Pollen Creek and to the south to continue as Caira Creek. Nimmie Creek water joined up with Pollen Creek but also flowed to the northwest to inundate areas near the river. Between Nimmie Creek and Waugorah Creek, conveying water to the south, smaller channels take water to the floodplain. Waugorah Creek flows southwest to fill channels and floodplains and links up with Monkem and Talpee Creeks that similarly flow to the south to join up with the main channel of the Murrumbidgee River. The Murrumbidgee River also has many small channels that convey water to the south. North and west of the Murrumbidgee River, the Redbank system is a large floodplain dissected by channels with no defined distributary creeks. This area is primarily reliant on overbank flows caused by a constriction in the main channel capacity of the river.

Yanga National Park 65 Flood regimes (time, frequency and duration) and patterns (spatial distribution of the water) in the Lowbidgee floodplain have changed dramatically due to upstream development as well as the management of the Lowbidgee Scheme (Table 23; Eddy 1992; Kingsford 2003; Page et al. 2005). Kingsford (2003) summarised the development of the area since European settlement and distinguished three major periods: before 1912, 1939–80, and after 1980 when most of the development was completed. As flow records are available only after 1936 for both Maude and Redbank gauging stations, the natural flow regime (i.e. before 1912) for the Lowbidgee floodplain cannot be restructured without complicated modelling. However, comparison of river discharges before and after 1970 (1937–70 and 1971–2007) downstream of Redbank Weir (Figure 31) indicates that the frequency of overbank flow decreased by more than 50%,

Table 22: Hydrological processes in Yanga National Park

Process Description Overbank Overbank flow is an infrequent, high-flow event that breaches riverbanks. flows Overbank flow occurs when river discharge reaches 7500 ML/day, 9500 ML/day and 20,000 ML/day at Balranald, Redbank Weir and Maude Weir, respectively. The Lowbidgee was flooded naturally in 15–20% of the years before European settlement (Pressey et al. 1984). As the hydrological records at Redbank and Maude weirs began in the late 1930s, the pattern of natural overbank flow cannot be restructured without complicated modelling. Nevertheless, the investigation of available river discharge records (1937–2007) at Redbank Weir reveals that while the median duration of floods (defined as the consecutive days of overbank flow) has not changed significantly, the frequency of overbank flow at Redbank Weir has been halved from 18.5% (1937–70) to less than 9% (1970–2007) (Wen et al. 2009). Furthermore, Yanga National Park has not experienced natural overbank flow since 1997 (Wen et al. 2009). Artificial To compensate the reduction in natural overbank flows due to upstream water watering extraction that resulted in a decrease in agricultural productivity, Maude and (including Redbank weirs were constructed primary for diverting water (’surplus flow’) to the environ- Lowbidgee FCID. Surplus flows to Yanga National Park are primarily via Yanga mental water regulator, and the delivery of water follows the natural network of waterways with allocation) relatively minor assistance or guidance from constructed channels or levees. The volume of diversion depends on the available flow in the Murrumbidgee and on climatic conditions with a median of 38.7 GL/yr (Figure 31), and the timing of diversion generally follows the demand for agriculture (autumn and winter). Rainfall and Rainfall in Lowbidgee is highly erratic with slightly more rainy days and higher evaporation rainfall in winter (Figure 5, section 2.2). Evaporation is high, ranging from 190 to 200 cm/yr. Groundwater There is no detailed study investigating the interactions between surface water exchange and groundwater. A study conducted for the river reach between Hay and Maude estimated high transmission loss (0.5% per km) (WRC 1982) suggesting a high rate of groundwater recharge. However, the recorded river discharges at Maude and Balranald suggest a much lower loss at this reach. The topsoil (to 1 m) at Yanga National Park has low saturated hydraulic conductivity (less than 2 mm/hr), except for the higher ground, less flooded, areas (EAS 2008).

66 Description of wetland ecological character Dry season Dry (e.g. fine and coarse, organic debris) providing varied niches niches varied providing debris) organic coarse, and fine (e.g. for regeneration topsoil infiltration bank) (egg stages resources greater prey waterholes to permanent confined 2. Regenerationgum) red (e.g.oftree River 3. Waterrecede tables 4. establishment Seedling 5. of grass species and colonisation terrestrial Encroachment 6.population of terrestrial fauna Establishment 7. waste, and animal as litter, matter of organic Accumulation 2. increase turbidity Nutrient, salinity, 3. of organisms Concentration 4. fish stranded the of predation avian and Dying 5. composition and drift in species algal abundance in Increase 6. among and competition Predation biota increase 7.community of vegetation Rezoning 8. on persistent go or refuge find either invertebrates Aquatic 9. Waterbirds disperse wetlands; to withother other areas 10. small and usually Rookeries waterbird breeding. Limited 11. sediment of Consolidation 1. types sediment withdifferent of sites of variety Formation aquatic habitats ephemeral/permanent Isolated 1. groundwater and evaporation to due decreases Waterlevel Confined to channels 1. upstream from inputs material Main 2. connect through May subsurface to the floodplain flow. dissolved nutrient (DOC, N, N, (DOC, nutrient dissolved to river export salts P), and to river move fauna erosion soil and as bank floodplain Fishesmove to river river to invertebrate drift maximum reaches completed. breeding floodplain surrounding 1. Water to river back flows 2. (litter), Coarse materials 3. aquatic other and Fish 4. river to exports Sediment 5. productivity high Maintain 6. Recharging aquifers river and Connected to 1. exports matter Organic 2. growth Peak phytoplankton 3.plant aquatic Plankton, 4. waterbird of Abundance 5. Colonial waterbird 6.infeed Fledged young Flood season Flood matter input and invertebrates grow on floodplain increase food sources waterbird breeding colonial (dispores, sediment, nutrient) inputs drowned or preyed and vegetation, litter understorey topsoil matters (e.g. salt) enter river 3. to river from move floodplain invertebrates Fish and 4. edge. channel along and feed roost waterbirds of Small numbers 1. material associates Water and 2. or escape fauna Terrestrial 3. live from release Nutrient 4. booms production Primary 5. aquifers Recharging Connected to river and floodplain 1. organic and sediment Nutrient, 2. emerge bank Seed/egg 3. plants aquatic of growth Rapid 4. rapidly enter, and Fishes spawn, 5. Number waterbirds of as increase 6. initiate events Largeflood Connected to floodplain 1. propagules plant Fish and floodplain. enter 2. and wood debris) other Nutrient, matter organic (fine/coarse/large Upward limb Upward limb Downward Limb River hydrograph River Bank full level Floodplain forest forest Floodplain woodlands and Lakes andwetlands Rivers and anabranches Figure 30: regime flood a natural under processes ecological floodplain and other cycle Relationships between hydrological

Yanga National Park 67 from about 18.5% to less than 9%. The year 1970 (rather than 1980 as in Kingsford and Thomas 2004) was chosen as a benchmark because the reduction of river discharge at Hay became significant only after the late 1960s (Wen 2009). The dramatic decrease in the frequency of overbank flows may be the single most important factor contributing to the continuous deterioration of river red gum condition in Yanga National Park.

There have been dramatic changes in hydrology downstream of Redbank Weir since 1970 (Figure 31). The annual median flow decreased by more than 60% from 2727.0 ML/day to 1048.5 ML/day (Table 24), with a reduction observed for every month. The biggest reduction (up to 90%) is in November, when the natural spring peak flow occurs. The peak flows are in September, when the demand for irrigation is at its lowest.

Table 23: Major developments on the Murrumbidgee River 1855–1982

Period Development Relevant particulars 1855– Deepening of Yanco Creek opening 1902 to increase water diversions from the Murrumbidgee 1880– River pumps used to take water from During 1979–90, an average 301.6 GL was present the Murrumbidgee for irrigation, town taken annually for irrigation, 36.0 GL for water supply, domestic and livestock other uses. use 1907–27 Burrinjuck Dam stage 1 Total capacity of 951.9 GL 1912–27 MIA developed Receives up to 780 GL per year diverted from the Murrumbidgee River; licensed irrigation area about 150,000 ha. 1914–57 Burrinjuck Dam stage 2, capacity Total capacity of Burrinjuck Dam is 1026 increased by 400 GL GL; first supply water to MIA in 1912. From 1979–90, annual mean division is 1143.5 GL. 1928 Yanco weir constructed Capacity of diverting 700 ML/day to irrigation areas and properties along Yanco Creek 1936–40 Maude Weir constructed Diverts water to Lowbidgee Irrigation Area. Mean annual diversion (1970–82) is 100.4 GL. 1937–40 Redbank Weir constructed Diverts water from the Murrumbidgee to Lowbidgee Irrigation Area. Mean annual diversion (1970–82) is 77.7 GL. 1956– 62 Main expansion of Coleambally Received up to 600 GL per year from Irrigation Area Murrumbidgee River. Licensed irrigation area approximately 80,000 ha. 1958–68 Snowy–Tumut Hydroelectricity Diverts up to 600 GL per year from Snowy Scheme River to Tumut River 1965–68 Blowering Dam built Capacity 1626.0 GL, storing water diverted from the Snowy River system and regulating flow in Tumut River 1982 Hay Weir constructed Capacity 13.5 GL. Mean annual division (1979–90) is 7.7 GL.

Data sources: DWR (2001); Pressey et al. (1984); Kingsford and Thomas (2001)

68 Description of wetland ecological character Both the 30-day maximum and minimum flows decreased, and the duration and frequency of extreme low flows increased 33.3% and 300%, respectively. One direct impact of the decreased flow is the reduction of floodplain inundation, which depends on the overbank flows. The frequency of bankfull river discharge declined by 53.0% from 18.5% to 8.7% (Table 24), which may be the single most important factor contributing to the continuous deterioration of river red gum condition in Yanga National Park.

Table 24: Changes in selected hydrological indicators in the Murrumbidgee downstream of Redbank Weir

Indicator * 1936–70 1971–2007 Change (%) Annual median flow (ML/day) 2727.0 1048.5 –61.6 30-day maximum flow (ML/day) 10,368.0 7430.4 –28.3 30-day minimum flow (ML/day) 691.2 259.2 –62.5 Extremely low flow^ duration (days/yr) 7.5 10.0 33.3 Extremely low flow frequency 1.0 4.0 300.0 Rate of change (m3/s/day) 1.6 0.6 –62.5 Frequency of bankfull flows (%) 18.5 8.7 –53.0

Data source: Wen et al. (2009) * Median values except for overbank flow frequency ^ Flows fall below the 10% percentile during the corresponding period

Monthly flow distribution at downstream of Redbank Weir 250 Before 200 After

150

100

Mean monthly flow (GL/day) 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Data source: Wen et al. (2009)

Figure 31: Monthly flow distribution before and after 1970

Yanga National Park 69 6.1.2 Artificial watering

Following the completion of Redbank and Maude weirs, surplus river flows were diverted to Yanga National Park through three pathways (Figure 32): a) Yanga regulator, where the majority of diversions to Yanga take place, b) Waugorah regulator, c) the Nimmie–Caira FCID. The distribution of water within Yanga National Park is primarily overland flow, following natural flood runners. The diversion from Nimmie– Caira FCID (via Maude) fills Tala Lake (a major irrigation storage, part of which is in Yanga National Park) via Talpee Creek. The historical records of diversion to Yanga National Park through Yanga and Waugorah regulators (Figure 30) were estimated by eye, thus only provided a best guess for water supply to the floodplain.

Irrigation Waugorah Block Block Waugorah Flood And district Irrigation Nimmie-Caira Regulator Yanga Redbank Crop /Narrockweel Block White Elephant Channel Yanga Monken Regulator Piggery Creek Redbank Lake Tarwillie Weir Block Swamp Block Creek Talpee Deadman’s Creek Murrumbidgee River

Nunkungerie Bottle Gate Regulator Creek Breer Swamp Creek Pee Vee Block Breer Creek Block

Breer Regulator Tala Tala Creek Lake

Woolshed Regulator

South Tala Block Channel flow Kieeta Regulator Overland flow Uara Block Floodplain Ephemeral Waterbody Yanga Yanga Creek Lake Balranald Weir

Based on Clarkson (2000) Figure 32: Irrigation water distribution pattern in Yanga National Park

70 Description of wetland ecological character Over the years a complex bank system has been developed in Yanga National Park to maximise the value of diverted water for livestock. For example, Piggery Lake was artificially divided into three sections with different water levels separated by banks and broad spillways. Other significant alterations include banking up water in Tala Lake with a weir, diverting water to Yanga Lake by blocking the effluent channel, and stopping southern flow from Tala Lake by the Woolshed regulator. As there is no volumetric allocation for Lowbidgee FCID, the district is dependent on unregulated flows in the Murrumbidgee for water diversion. There is a marked seasonal pattern in the operation of Redbank Weir, most diversions being made in the late winter and early spring months reflecting crop water requirements. Large variations occur from year to year (Figure 33) as the operations depend on natural flooding, the available water and, to lesser degree, local rainfall. The values were a ‘best guess’ by Department of Water and Energy staff. In 2007, a gauge was installed at the Yanga regulator to record the environmental flow allocations into Yanga National Park as part of the RERP subprogram Better use of environmental water. The gauge will improve the accountability of environmental water usage.

6.2 Geomorphologic processes Geomorphologic processes are key drivers of floodplain ecology. Sediment erosion and deposition and episodic avulsion are dominant geomorphologic processes within lowland floodplains.

6.2.1 Sedimentation Sediments are mineral particles that are transported by flowing water. These typically include fine silts, coarser sands, gravels and larger cobbles that are progressively eroded and transported by flowing water. During floods, sediments enter and deposit on the floodplain (Figure 34) and create a variety of geomorphic features which provide principal nursery sites for colonisation by riparian plants.

160

Annual diversions to Yanga 140

120

100

80 GL

0 81/82 82/83 83/84 84/85 85/86 86/87 87/88 88/89 89/90 90/91 91/92 92/93 93/94 94/95 95/96 96/97 97/98 98/99 99/00 00/01 01/02 02/03 03/04 04/05 05/06 06/07 Water Year

Data source: DWE operational data Figure 33: Water diverted to Yanga National Park from the Murrumbidgee River

Yanga National Park 71 Different sediments provide different physical properties, including the capacity to retain water, which is essential to sustain vegetation in semi-arid regions. Fine sediments drain more slowly and have increased capillarity – the capacity to draw water upwards to create a moist zone above the water table (the capillary fringe). This unsaturated zone is especially important for providing water to floodplain plants and the extent of the capillary fringe varies substantially with sediment texture (particle size), ranging from being only a few centimetres above coarse gravel to more than a metre above silty-sand (Hughes 2003). Therefore, as well as being critical for the formation of new nursery sites, alluvial sediments are also critical for the retention and provision of moisture during dry periods.

Sedimentation processes in the river-floodplain system

Geomorphic features formed from valley sediments are diverse, but some are common to all river systems. Their development can be associated with general links between sediment storage sites and erosion processes that occur within floodplain and channel areas, as shown in Figure 34 and described below. Gradually accumulated rock and soil (colluviums) and mass-movement deposits are generally located at the valley margins. These sediments are put in motion by sheets of running water (sheet erosion). Depending on the local topography, the sediments move slowly over gradual slopes (soil creep), and rapidly over steep terrain (debris slides and flows), and are carried to the floodplain, channel margin, or stream channel. Deposits on the floodplain (overbank deposits) have various forms such as vertical build-up (vertical accretion) and local, fan-shaped slopes (splays). This area may be eroded by slides cutting into banks (slide-scarp erosion), gradual slides of a wider expanse of land (slide-sheet erosion), or debris slides and flows that move sediments to the channel margin during floods. Point and marginal bars (lateral accretion deposits) are formed in the channel margin. These sediments enter the channel by erosion of gully walls or stream banks. The sediments may accumulate in the channel (channel fills), be deposited and resuspended (transitory channel deposits), or form sand bars and islands when the deposit is not so transitory (lag deposits). Sediments may be taken up again by erosion of the stream bed or island banks and redeposited in the channel margin or in the floodplain as overbank deposits.

Sediment sources In terms of geomorphology, the Murrumbidgee catchment can be divided into three distinct regions (Figure 35): the upper, middle and lower Murrumbidgee (Olley and Scott 2002, p 1994). The hilly upper region is the principal area from which dissolved solids and sediments are derived. However, the two large dams, Blowering and Burrinjuck, effectively cut off the upper catchment from the middle and lower river, and trap most of the sediment (Murray et al.1992; Olley and Scott 2002). The middle catchment is featured by undulating terrain dissected by numerous gully networks (Olley and Wasson 2003). Most of the major tributaries join the Murrumbidgee in this region (Olley and Scott 2002). This is the major source of fine-grained sediment transported to the lower Murrumbidgee (Olive et al. 1994). There is essentially no input (runoff, therefore suspended solids) from the catchment downstream of Wagga Wagga (Murray et al. 1992). Bank erosion is the main process contributing to in-stream turbidity in this region. While 15% of bank length was considered as unstable between Berembed Weir and Hay, it was estimated that 8% of bank length was classified as unstable downstream of Hay (DLWC 1995). Bed mobilisation in this reach is of little significance except at weirs where downstream scouring occurs over short distances (DWLC 1995).

72 Description of wetland ecological character Boxes contain storage locations with example sediments and erosion processes. Arrows represent the links between the various storage sites largely driven by water movement and gravity. Figure 34: Sediment erosion and deposition processes in the river–floodplain system

From Olley and Scott (2002) Figure 35: The three geomorphic regions of the Murrumbidgee catchment

Yanga National Park 73 Along the river reach from Hay to Balranald, bank erosion occurs as a result of meander movement. When water recedes, bank slumping contributes a major proportion of sediment in the river.

River regulation, such as the construction and operation of dams and weirs, has an inevitable impact on sedimentation patterns and thus on the water retention capacity of the floodplain. All but the finest sediments settle out in the slow-moving reservoirs and weir-pools and, consequently, the released water is typically depleted of sediments and sometimes referred to as ‘hungry water’. Without sediment transport, the riparian zones and floodplains downstream of major dams and weirs lack areas of sediment deposition and new nursery sites become deficient. Further, the sediment-depleted outflow water has substantial capacity to erode and remove the sediments that were present. Over time there is the progressive depletion of alluvial sediments with corresponding loss in suitability for floodplain vegetation and reduction in primary productivity as well.

Few data exist to quantify sediment dynamics within the Lowbidgee floodplains, partly due to the episodicity of transport events and, more importantly, the lack of long-term monitoring data. However, a palaeoecological study by Gell and Little (2006), which took cores at Balranald Weir and Waugorah Lagoon, estimated that the sedimentation rate was as high as 8.8 mm/yr at weir pools contrasting to around 1 mm/yr (low) to 20 mm/yr (relatively high) in the floodplain swamps.

6.3 Nutrient cycling and trophic dynamics

Although a multitude of concepts, principles and methodologies exist to assist in understanding the biological interactions in floodplain wetlands, the level of knowledge is still relatively rudimentary: very little quantitative information is available on primary productivity, and even less on secondary production. This is particularly true for Yanga National Park: the effects of primary productivity, herbivory, competition and predation on Yanga National Park biota are largely unknown although these processes have an important role in structuring the biological community in aquatic and forest ecosystems. Two current projects will greatly increase the knowledge and understanding of food web structure and trophic dynamics in Yanga National Park:

Trophic dynamics and ecosystem function of the lower Lachlan and Murrumbidgee (Rivers and Wetlands Unit, OEH)

Examination of organic matter dynamics and secondary production in floodplain wetlands of the lower Murrumbidgee River (Murray–Darling Freshwater Research Centre).

74 Description of wetland ecological character 7 Limits of acceptable change to key ecological components

The concept of limits of acceptable change (LACs), illustrated in Figure 36, is a useful tool, widely used to identify and set limits within which change may be tolerated (Ramsar Convention 1993). It may be applied to long-term or operational objectives. Once these limits are exceeded there will be a need for immediate remedial action.

Natural Limits of variability acceptable change

Long-term variation in a parameter (e.g. salinity, population)

After Phillips and Muller (2006) Figure 36: Limits of acceptable change

It is essential to have the knowledge and long-term data and information to assess the range of natural variations in order to set LACs for the components and processes under consideration. This is particularly important for Australian wetlands given that they often have a large range in natural variability (Finlayson and Mitchell 1999; Thoms and Sheldon 2002; Sheldon 2005). However, due to the lack of long-term monitoring programs for this site, the information and data available for setting LACs for most of the ecosystem components, processes, and services presented in the previous sections are less than ideal. Consequently, the proposed LACs are based on a range of information such as specific research, information from similar sites, national and state guidelines and standards, and knowledge of site managers and local residents while considering the site-specific characteristics. Some of the given LACs should be considered as interim.

Another difficulty in setting definite LACs for some ecosystem components and processes is that changes may not be caused by site management. For example, the species composition, distribution, and abundance of migrant birds are known to be highly variable. This may reflect annual differences (changes) in habitat availability elsewhere, variation in climatic conditions, annual variation in the period of peak migration, or annual fluctuations in sizes of bird populations. Thus, exceeding a LAC may send a false alert to wetland and park managers. In this case, a precautionary approach was adopted, especially for threatened species.

Table 25 provides a summary of LACs for the critical components and processes of Yanga National Park. Where appropriate, information required to set definite LACs was identified.

Yanga National Park 75 Targeted areas get the Targeted areas entitled allocations. 60% of the area is inundated at least once every 10 years. Advice is needed to of address the impacts climate change. Long-term (10–100 years) (10–100 Long-term An adequate share of An adequate the allocated to water is such that environment Two targeted areas (e.g. Bridges Swamp, Shaws Swamp, Mercedes Swamp, Piggery Lake) are flooded forsixmonths years every three High conservation areas High conservation (e.g. Two Bridges Swamp, Mercedes Piggery Swamp and Lake) are inundated once every two years. Advice is needed to of address the impacts climate change. Interim limits of acceptable change Short-term (1–5 years) 3 Highly variable. Floods with return periods more than 20 years more than with return periods Floods Highly variable. Baseline condition and range of natural variation where variation of natural and range Baseline condition known flooding occurs in 15–20% of years. The impacts of climate of climate impacts of years. The flooding occurs in 15–20% to reduce the high flow frequency. River change are likely medium and the low reduced dramatically has regulation no natural been there has and 1970s, the since flows overbank flow since 1996. Park. (e.g. 1974) cover more than 90% of Yanga National 60% around inundate years return periods with 5–10 Floods will current inundation mapping project of the area. The detailed data. provide more data. The current hydrodynamic modelling project and network in Yanga National Park may hydrological monitoring provide information to fill the gap. surface/groundwater to draw any conclusion about insufficient relationships. as set out in the Water Sharing water availability Depends on Source River Water Regulated Plan for the Murrumbidgee 2003. Table 25: Table 25: Park components and processes of Yanga National Limits of acceptable change for critical Critical ecological and components processes Hydrological Inundation frequency natural High flowsare event driven, and large Highly variable. Inundation area Inundation duration No quantitative both temporally and spatially. Highly variable inputs Groundwater and temporally are spatially data monitoring Groundwater Environment water allocation www.austlii.edu.au/au/legis/nsw/consol_reg/wspftmrrws2003648 www.austlii.edu.au/au/legis/nsw/consol_reg/wspftmrrws2003648 3

76 Description of wetland ecological character No net reduction in the of waterbird number recorded. species in No net reduction abundance. Long-term (10–100 years) (10–100 Long-term Within the ANZECC & (2002) ARMCANZ guidelines for inland rivers. Insufficient data to set limit. Advice needed. Advice needed. 2–20 mm/yr in swamps 2–20 mm/yr in swamps 2–20 mm/yr in Within the ANZECC & (2000) ARMCANZ guidelines for inland rivers. Insufficient data to set limit. Falling below 21 in two Falling below years based consecutive aerial on the ongoing survey. Below 42 in two years based consecutive survey. on ground Less than the minimum for count 22,000) (about years two consecutive survey. based on aerial Interim limits of acceptable change Short-term (1–5 years) 8% of bank length is unstable. Historic aerial photography shows little channel movement. Baseline condition and range of natural variation where variation of natural and range Baseline condition known Spatially variable. No field measurements available. A available. measurements Spatially variable. No field rate that the sedimentation palaeoecological study estimated mm/yr at weir pools but ranged from 1 was up to 10 swamps. A (very low) to 20 mm/yr (quite high) in the floodplain thecurrent project to establish benchmark and trajectory of will provide data to fill the gap. sedimentation No data. Salinity: good (100–300 μS/cm). (6.5–8.0). pH: excellent TP: poor (50–80μg/L), occasionally very poor. Turbidity: fair (16–30 NTU). poor, but insufficient data. DO: generally spatially and temporarily. Limited data suggest Highly variable floods especially very poor following water quality is likely to be after a long dry period. but no survey after the 1980s in the regions of bird surveys Park. Up to 61 species National in Yanga undertaken was wet a was which (1990), Maher in 1989 by were recorded et al. (1984) by Pressey recorded were year. 42 species survey aerial Continuously (1982–83). drought severe during varies of water species the number suggests from 1983 region, of 21–40 in the Lowbidgee considerably with a range observed. was trend declining and a general No data to set limit. ranging from variable the abundance is highly suggests that No data to set limit. in the trend declining strong a and shows 21,700 to 139,000, region. Lowbidgee Critical ecological and components processes and chemical Physical Sedimentation rate (mm/yr) Bank erosion loadings Nutrient (tonne/yr) Water quality at channel (Murrumbidgee Redbank) Water quality waters) (floodplain Biological * species Waterbird A number development. resource water before Little is known Waterbird abundance* survey aerial The There is no data1980s. before the

Yanga National Park 77 ies. Advice needed. No net loss in native fish species. No net loss in native fish species. species. of No net loss Advice needed. 10 years. wetlands. Advice needed. Long-term (10–100 years) (10–100 Long-term

No loss of river red gum red of river No loss forest/woodland. Data insufficient at this time. Data insufficient at this time. LACs for native fish are closely species linked with the River Murrumbidgee channel. Data insufficient at this time. in of population No loss key sites. Dry to full No loss of wetlands. No net loss in area of Inundated at least once in Condition of riparian vegetation at key sites (Two Bridges, Breer Swamp, Talpee Creek, is Piggery Lake) maintained. Interim limits of acceptable change Short-term (1–5 years) Baseline condition and range of natural variation where variation of natural and range Baseline condition known last ha for the at 22,000 remains red gums The area of river photography. based on aerial 5–6 decades Some studies sampled the lower Murrumbidgee channel. channel. Murrumbidgee the lower sampled Some studies in 2000–01. were recorded species Nine Five is scarce and unsystematic. the 1990s Information before in recorded were eight and in 1999 sampled were species 2008. to introduced low compared was Native fish abundance types of habitats. species in all in diversity and reduced No information and data. Likely loss. of habitat because abundance widely distributed and abundant bell frog was The southern swamps) black box/lignum and forests red gum (river until the early 2000s. It is floodplain throughout Lowbidgee when the population began to decline. Currently, unclear key sites there are low numbers of southern bell frogs in Two Bridges). (Mercedes, the variations in open water area of data documents historical the lakes. Mercedes Swamp. been has forest/woodland of river red gum The condition since the 1970s. Currently, there are only about declining The remaining 2000 ha of river red gum in good condition. are in poor to very condition. Around 1350 ha forests dead tree stands. Critical ecological and components processes Native fish (Murrumbidgee channel) Native fish water bodies) (floodplain Number of invertebrates abundance and species and Abundance southern of distribution bell frog species Other threatened recorded. species and vulnerable endangered There are 22 Habitats in diversity. No changes spec of No net loss lakes floodplain Large No 2001. dry since have been and Tala Lake Yanga Lake Shallow marshes River red gum forest/woodland Twin Bridge Swamp, Around 1500 ha, includes Piggery Lake,

78 Description of wetland ecological character Advice needed. No loss in area of lignum shrublands. Long-term (10–100 years) (10–100 Long-term sed on ground-based data. No loss of black box box of black No loss woodland. No loss in area of lignum shrublands. Advice needed Advice needed Interim limits of acceptable change Short-term (1–5 years) implemented, LACs should be ba toring data, LACs for species and abundance of waterbirds are based on aerial survey. nitoring program is to be Baseline condition and range of natural variation where variation of natural and range Baseline condition known There are about 12,000 ha of black box in Yanga National has remained Park. The extent of black box woodland last 50 years, based on aerial photography. constant for the There are about 1300 ha of lignum swamps in Yanga National Park. In the Nimmie–Caira country, large areas of lignum a as by cumbungi are being displaced or swamp were cleared result of prolonged inundation. The condition of black box woodland has been declining since since declining been has woodland of black box The condition the 1970s. condition. Poor to very poor More than 30,000 ha. Advice needed. No net loss. Advice needed. No net loss. However, if long-term ground-based bird mo * is the only available long-term moni As the aerial bird survey Critical ecological and components processes woodland Black box Lignum swamp Other terrestrial woodland and bushland

Yanga National Park 79 8 Actual and likely threats to the ecological character of Yanga National Park

The aim of this section is to identify the threats to ecological character, i.e. those that cause adverse changes in the ecological character of Yanga National Park. The threats are summarised in Table 26 using the threat classification hierarchy developed by the International Union for the Conservation of Nature and the Conservation Measures Partnership (IUCN-CMP),4 and detailed in the following sections. Because of the geographic settings and agricultural history, the threats identified for the Lowbidgee floodplain are also applicable to Yanga National Park.

Based on Table 26, a conceptual model (Figure 37) was developed specifically for risk management for Yanga National Park. Because of the land tenure change, and thus the development of a management strategy, many threats identified in Table 26 (e.g. agriculture) were not included in Figure 37. Furthermore, climate change and a mitigation and adaptation strategy should be addressed at global, national and regional scales; therefore these are not included in the model. The model illustrates the ecological linkages among the major threats (distinguished as external pressures and system-wide stressors), effects and ecological characters. The cause and effect relationships explain the important consequences of system-wide stressors on the major ecological attributes of Yanga National Park. These stressors, which include flood reduction, loss and shift of natural discharge variability, floodplain loss and fragmentation, are further discussed below.

8.1 Alteration to the natural flow regimes

Alteration to natural flow regimes refers to reducing or increasing flows, altering seasonality of flows, changing the frequency, duration, magnitude, timing, predictability and variability of flows, altering surface and subsurface water levels, and changing the rate of rise or fall of water levels (NRC 1992). In the lower Murrumbidgee downstream major irrigation areas, the alteration is realised principally as reduction in river flows (Page et al. 2005; Wen 2009). Alteration to natural flow regime and water resource development is directly related. In Lowbidgee, like elsewhere in the Murray–Darling Basin, natural flow regimes have been interrupted through three human processes due to water resource development pressure: river regulation (dam and weir), water diversion (includes groundwater pumping), and alteration of flows within floodplains with levees and structures (such as bank enforcement).

Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands is listed as a key threatening process on Schedule 3 of the TSC Act. A direct and most significant consequence of alteration to the natural flow regimes in the Lowbidgee floodplain is the dramatic reduction in frequency and duration of overbank flows, which in turn is recognised as a major factor contributing to loss of biological diversity and ecological function (Briggs et al. 1997; Sherman et al. 1998; Kingsford and Thomas 2004; Gilligan 2005; Wen et al. 2009). Impacts associated with reduced flooding relevant to Yanga National Park include: loss of lateral connectivity with the Murrumbidgee loss of persistent soil moisture levels loss of ecological function increased fire risk ultimately, degradation of floodplain habitat.

4 http://iucn.org/about/work/programmes/species/red_list/resources/technical_documents/new_classification_schemes/

80 Description of wetland ecological character 8.2 Habitat loss and fragmentation

Together with the reduction of flooding, floodplain development, which includes the construction and enforcement of banks, levees and regulators, clearing of lignum, and creation of water storages, accelerated the loss and fragmentation of floodplain habitats in the Lowbidgee floodplain. While the development of floodplains for agricultural production in Yanga National Park ceased in 2005, existing infrastructure in the Nimmie–Caira system has management implications for Yanga National Park. For example, the blockages along Fiddlers Creek prevent water entering Yanga Nature Reserve. Using historical floodplain maps and satellite imagery, Kingsford and Thomas (2001) investigated floodplain loss in Lowbidgee from the turn of the 20th century. They found that 127,688 ha (58%) of wetlands have been lost to developed land in the lower Murrumbidgee region. In Yanga National Park, the loss was 37,253 ha (41%). In the developed area of the lower Murrumbidgee floodplain, particularly in the Nimmie–Caria FCID, a water delivery and retaining network, which has about 2,100 km of banks and 394 km of constructed channels (Kingsford and Thomas 2001), has been developed since the completion of Redbank and Maude weirs. The main purpose of the network is to deliver water efficiently and quickly. However, besides distributing floodwater, the natural floodway network, including streams and flood runners, also provides hydrological continuity for nutrients and aquatic animals such as fish, amphibians and waterbirds. Consequently, the development and operation of the modified network has increased habitat isolation through preventing water reaching some floodplain areas and prolonging inundation of targeted areas. For example, the Southern Caira channel was built to bypass the floodway and allow more efficient transmission to irrigated areas downstream and key habitat areas (DLWC 1997). In the meantime, the channel bank also isolated the southern part of the floodplain from flood flows because it was constructed above the estimated 1956 flood level (one in 100 years) at the site and did not allow passage of floodwater, so the levee needed to be breached during floods (DWR 1994). The diversion of water from Redbank and Maude weirs is generally beneficial for the flora and fauna on the Lowbidgee floodplain as it compensates the reduction of overbank flow due to upstream water extraction. For example, bank construction and water storages have enhanced waterbird breeding, particularly ibis, in the Telephone and Eulimbah swamps (Maher 1990). However, water storages, which have artificially enhanced wet periods (more than two years), may be of lower quality as waterbird (Maher 1990) and fish habitat. Furthermore, the prolonged inundation favours the spread of cumbungi (Typha domingensis) (Pressey et al. 1984; Maher 1990; Eddy 1992; DLWC 1997; Kingsford and Thomas 2001). In more permanent water habitats, cumbungi tends to dominate over lignum and becomes a major cause of decline in lignum areas in the Lowbidgee (DLWC 2000). In April 1997 the Nimmie–Caira floodway system was infested with approximately 3530 hectares of cumbungi, representing some 15% of the total floodway vegetation (DLWC 1997).

Yanga National Park 81 Low Low Medium High Likelihood Medium–long Medium–long High Immediate–medium Immediate–medium Medium Immediate Medium–long High Medium–long Immediate–medium Medium Immediate–medium Immediate–medium Medium Timeframe Immediate–medium Immediate–medium Low Immediate–medium Immediate–medium High Immediate Flood Irrigation salinity Irrigation salinity Sheet erosion Medium Immediate–medium Low Low Arson Immediate–medium Low Low Low Immediate–medium Arson Immediate–medium Recreation Immediate–medium Recreation Encroachment of chenopod into sedge Threat agent Threat agent 3) level class: (threat water extraction surface Upstream floodgates, Structures, including Immediate–medium crossings levees, road culverts, High water Loss of open Habitat change Natural fire Illegal take of vegetation health Deterioration Medium–long High Wind erosion Wind erosion Threat activity activity Threat 2) level class: (threat diversion water and Dams Habitat shifting and alteration Agriculture Clearing crops Annual non-timber Livestock/native animal grazing Immediate–medium Grazing cropping pastures and Irrigated Immediate–medium Medium Drought Drought Storms and flooding Medium–long Strong wind Fire and fire suppression aquatic and harvesting Fishing resources extremes Temperature degradation Ecosystem change Water temperature Medium–long Medium Threat theme theme Threat 1) level class: (threat Natural system modifications Agriculture Biological resource use Hunting of waterbirds and Climate change severe weather Ecosystem/community stresses Table 26: Table 26: floodplain of the Lowbidgee character Summary of actual and likely threats to the ecological

82 Description of wetland ecological character Low Low Low Low Medium Low Likelihood Immediate–medium Immediate–medium Medium Immediate–medium Immediate–medium Low Medium Timeframe Immediate–medium Medium Immediate–medium Immediate–medium Immediate–medium High Immediate–medium Immediate–medium Medium Immediate–medium Immediate–medium Medium Immediate–medium Immediate–medium Low Allocation of environmental water Allocation of Immediate–medium Medium Low Other plants Immediate–medium Sediments Immediate–medium Low Ecotourism Medium Low Medium Ecotourism Toxic algae Low Immediate–medium Immediate Pesticides High Threat agent Threat agent 3) level class: (threat Hunting Immediate–medium carp European Feral pig Red deer Feral cat Rabbit European red fox Lippia Immediate Herbicides Nutrients Immediate Toxins Immediate soils Acid sulfate Immediate–medium Nutrients Threat activity activity Threat 2) level class: (threat Inappropriate conservation measures Invasive exotic species Agricultural effluent Recreational activities Recreational and species Other problematic genes Other sources Threat theme theme Threat 1) level class: (threat and intrusions Human disturbance other Invasive and and species problematic genes Pollution Threats adopted from IUCN-CMP, http://iucn.org/about/work/programmes/species/red_list/resources/technical_documents/n hierarchy ew_classification_schemes

Yanga National Park 83 Figure 37: Figure 37: Yanga National Park Conceptual ecological model of risks in

84 Description of wetland ecological character The development plan for the lower Murrumbidgee floodplain (DWR 1989, 1994) emphasised the conservation needs of identified special habitat areas or rookeries (e.g. Avalon Swamp, Nap Nap Swamp, Telephone Banks Rookery), while development was permitted elsewhere on the floodplain. Consequently, a constricted distribution of floodways (through enforcement of natural levees) and isolated rookeries (targeted artificial watering) would be maintained, reflecting the narrow definition of ecosystem function applied.

8.3 Introduced and problematic species

The Atlas of NSW Wildlife contains records of 58 introduced plant species in Yanga National Park, of which the majority are small ground plants, and some of these are widespread and abundant, such as Paterson’s curse (Echium plantagineum), horehound (Marrubium vulgare), onion weed (Romulea rosea var. australis) and spear thistle (Cirsium vulgare (Savi) Ten.). The wide spread of introduced small ground plants (some are valued as stock feed, e.g. medics – Medicago spp.) reflects the agricultural history of the site. The prolonged dry period in water-plant dominated areas (i.e. shallow temporary swamps) and lake beds increases the risk of exotic plant invasion.

As mentioned in section 8.2, cumbungi infestation of lignum swamps and permanent water ways is common at Lowbidgee, especially at Nimmie–Caria FCID due to the artificially enhanced inundation.

A number of surveys found that introduced fish species, in particular European carp, goldfish (Carassius auratus) and eastern gambusia, dominate waterways (including the Murrumbidgee channel and wetlands) (Bales 1999; Baumgartner 2004; Wassens 2008a; Spencer and Allman 2008; J Kelleway 2009, pers. comm.). Introduced fish species pose a threat to native fish species as predators, competitors, disease carriers and through modification of habitat (Fisheries Scientific Committee 2001) and are thought to be a significant contributor to reductions in native fish species abundance in the Murrumbidgee catchment (Gilligan 2005). Predation by European carp may also contribute to the decline in the southern bell frog population in Lowbidgee (Wassens 2008a). The introduction of fish to fresh waters within a river catchment outside their natural range has been listed as a key threatening process in Schedule 6 of the Fisheries Management Act (Fisheries Scientific Committee 2008).

Other introduced animals of concern include feral pigs, cats and European red foxes. These animals predate on small native animals (e.g. lizards, frogs and ground-nesting birds). They are all listed as key threatening processes in NSW by the NSW Scientific Committee because of their impacts on native animals (DECC 2008).

8.4 Climate change

Changes in global climate – warming temperatures, rising sea level and variations in rainfall and storm patterns – could have tremendous human and ecological impacts (Figure 38).

The resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change, associated disturbances (e.g. flooding, drought, wildfire, insects, ocean acidification) and other global change drivers (e.g. land-use change, pollution, overexploitation of resources) (IPCC 2007).

Yanga National Park 85 8.4.1 Higher temperatures

Increasing temperatures globally are likely to result in a warming of water in lakes and rivers. Increases in water temperature will cause a shift in the thermal suitability of aquatic habitats for resident species. The metabolic rates of organisms and the overall productivity of ecosystems are directly regulated by temperature. Projected increases in temperature are expected to disrupt present patterns of plant and animal distribution in aquatic ecosystems.

8.4.2 Changes to rainfall patterns and intensity

Some climate change models predict possible increases in the intensity and rainfall on fewer rainy days (Kattenberg et al. 1995), as has already been observed in precipitation data in Australia. The implications for streams and rivers and the water bodies are significant. A direct result of these is an increase in flood frequency and changes in flood magnitude. Because the transport and storage of nutrients and pollutants depend on flow, an increase in floods would probably result in more silt and pollutants entering streams and rivers and their receiving water bodies. The corresponding degradation in water quality could lead to a loss of sensitive stream species (Meyer et al. 1999). Further, floods scour the stream bed and displace stored organic carbon (food resources for many species), bottom-dwelling organisms and larval fish.

8.5 Other issues

Prior to 2005, numerous land management practices occurred in Yanga National Park, including grazing, clearing, logging and burning. Although all these practices have been stopped since gazettal as a national park in 2007, some of them have long lasting impacts on the ecological character of the site. Furthermore, these land management activities are practised in the surrounding areas, and have direct or indirect effects on Yanga National Park.

CO2 Rainfall pattern and intensity

Air temperature Runoff regime -Magnitude Water temperature -Frequency Human responses -Timing Sea level -Duration

Ecosystem responses -Biota metabolism -Species distribution -Habitat availability and quality -Habitat connectivity -Nutrient availability, productivity -Lake mixing -Water chemistry

Solid arrows indicate very likely impacts and dashed arrows indicate likely impacts (IPCC 2007).

Figure 38: Linkages between climate change and ecosystem responses

86 Description of wetland ecological character Grazing by livestock and native or other introduced animals has been observed to have a significant impact on the condition of vegetation communities in the Lowbidgee (Beadle 1948; Cunningham et al. 1981; Pressey et al. 1984; Scott 1992; Benson et al. 2006). Grazing has direct impacts on vegetation community structure by altering the relative abundance of floodplain plants. For example, more tolerant species, such as water couch (Paspalum distichum), are likely to become increasingly abundant as a result of intensive grazing, which may prevent the regeneration of river red gums (Jacobs 1955). Other impacts associated with grazing include puddling, trampling, reducing plant biomass and altered nutrient cycling.

Clearing, in particular the clearing of lignum communities, has occurred in the lower Murrumbidgee for decades, and 60% of the estimated 40,000 ha of lignum in Lowbidgee was cleared by 1988 (Cross et al. 1991, cited in Kingsford and Thomas 2001).

The river red gum forests of Yanga National Park have been logged to varying degrees over the past 150 years, and some areas have been extensively logged until very recently (Maher 1999). Large-scale logging could change the landscape from scattered, mature tree stands with patches of younger trees to dense even-aged regrowth; consequently, these areas would lose value as fauna habitats. For instance, apart from the general faunal values, hollows in river red gums are particularly important for breeding and sheltering of a range of species (e.g. grey teal, bats).

Small-scale burning has occurred in Yanga National Park to control the growth of common reed. Burning would have an impact on floodplain flora and fauna; however, the impact is likely to be localised and temporary. Burning in patches may even enhance the ecological values by diversifying the vegetation structure and breaking down soil organic matter, consequently accelerating nutrient cycling.

Yanga National Park 87 9 Knowledge gaps

There are substantial knowledge gaps that limit the optimisation of Yanga National Park management. These knowledge gaps are an ongoing problem for describing ecological character, setting LACs, identifying potential and actual threats, and initiating management actions to address the threats. Table 27 summarises the fundamental knowledge gaps and recommended actions to address the gaps. Many of these relate to the monitoring program recommended in section 10.

A number of scientific research projects, mainly under RERP, are currently underway in Lowbidgee (many focus on Yanga National Park) to investigate the relationships between floodplain ecology and hydrology. Three major components of the program are particularly valuable for filling the knowledge gaps identified in Table 27:

Physical settings digital elevation models based LiDAR Survey bathymetric for significant wetlands and lakes soil surveys. Hydrological drivers hydrodynamic modelling hydrological modelling Yanga flow gauging network groundwater monitoring network inundation mapping. Ecological responses trophic dynamics based on isotopic analysis of keystone species and trophic levels maps of current and historical vegetation extent and condition tree health survey seedbank and eggbank investigation Lowbidgee frog monitoring waterbird and fish surveys palaeoecological studies in key sites land-use and organic matter study.

The majority of these projects are currently at the phase of data collection; therefore findings and conclusions have yet to be incorporated in the description of ecological character. Nevertheless, the current vision of the description has integrated the most up-to-date data and information collected by the program, such as frog monitoring and historic vegetation mapping. It is strongly recommended that an updated vision which integrates the findings from these studies should be developed before the end of the RERP in 2011.

88 Description of wetland ecological character Table 27: Key knowledge gaps and recommended monitoring and actions Component and Identified knowledge Category Recommendations Priority process gaps Heritage Aboriginal and Most of the Aboriginal Liaising with Aboriginal Medium European heritage sites have been representatives to to high destroyed. identify heritage items and areas of spiritual significance Hydrological Surface/groundwater No quantified data to Monitoring Low to interaction estimate the surface/ groundwater levels medium groundwater interaction Floodwater including Preferential flow paths Digital elevation model High EWA distribution Distribution of temporary and terrain model patterns wetlands Inundation patterns Distribution, extent, Installation of gauges High for key wetlands duration and timing of in key wetlands inundation of key wetlands Habitat Temporary wetlands Macrophytes species Vegetation High abundance and abundance survey(prior to, during and quality River red gum forest Age class and current and post inundation) in /woodland condition key wetlands Response to inundation Permanent transects Lignum swamp Current condition in representative Response to inundation vegetation Black box woodland Current condition communities Response to inundation Fauna Waterbirds Understanding the Long-term monitoring High causes of declining trends in diversity and abundance Macroinvertebrates No comprehensive Annual survey of Medium macroinvertebrate macroinvertebrates in surveys key sites (including river channels) Threatened fauna No information about the Targeted survey High population trend of threatened species (other than the southern bell frog). Other fauna Lack of fauna surveys Fauna survey, Low to especially for bats, medium small mammals and reptiles Fish Fish usage of floodplain Fish survey across the Medium floodplain Introduced species Impacts of feral Scats and remains Low to predators on waterbirds analysis medium and small native mammal populations

Yanga National Park 89 Component and Identified knowledge Category Recommendations Priority process gaps Physical and Sedimentation rate There is little or Targeted study Low to chemical inconclusive information medium about the relationship between the rate of sedimentation rate and hydrological regimes. Water quality No systematic water Monthly water quality Medium quality data (DO, pH, at gauging sites when to high nutrients, salinity, water present turbidity) Human EWA Distribution and volume Installation of flow Medium disturbances gauges to high Park visitors Medium

10 Recommended monitoring program

10.1 Monitoring objectives

The objectives of the monitoring program are as follows: to gather information to provide or improve the understanding and description of the ecological character of Yanga National Park to obtain data and information about the natural variation range of critical ecosystem drivers, components and processes for setting LACs to detect change, or likely change, in the ecological character of the site as set out in sections 2–8 of this report to assess the efficiency of management actions and conservation efforts.

10.2 Recommended monitoring framework

The recommended monitoring framework for Yanga National Park is presented in Table 28. These recommendations are based on the knowledge gaps identified in section 8 and particularly those required for setting LACs as highlighted in section 7.

90 Description of wetland ecological character High High High Low High High High High Priority Priority Survey once High Continuously per event Every 3 years Every 3 years Once Annually in spring (weekly for targeted during species EWA) Continuously Continuously Continuously per event Frequency Frequency sites. Water level at key sites. Flow at key sites. Mapping extent of main vegetation types communities gum to river red given (priorities and sedge swamps). red gum tree stands. Condition of river gum forest. red of river structure The age species Presence or absence of waterbird species of target or absence Presence Numbers of breeding pairs of nests Number Number of fledges Water level and discharge at Maude Weir. Weir. Maude at discharge level and Water Redbank Weir. at Water level and discharge Discharge at Yanga regulator. Groundwater level. Continuously Medium Indicator/Measure Establish requirements of wetland of wetland Establish requirements communities Impact assessment. detection. Change of requirements Establish the water key communities. Set LACs. changes. Detect impact. Assess of waterbirds. Set LACs. impacts. Assess Establish the dependence of waterbirds on habitat in the Lowbidgee. Objectives Objectives Establish requirements of wetland of wetland Establish requirements within the Lowbidgee communities at this relates to discharge and how weirs. Redbank Maude and detection. Change Set limits of change Aboriginal sites sites Aboriginal conditions. Establish baseline status of Aboriginal Location and conservation Flow paths and distribution Vegetation types, floral structure, and distribution extent Waterbirds Establish the habitat requirements Monitoring component River flows Impact assessment. Groundwater conditions. Establish baseline Ecological character Cultural Hydrological Habitat abundance and quality Biological: fauna Table 28: Table 28: Park Yanga National for program monitoring Recommended

Yanga National Park 91 Low High High Priority Priority Monthly Low Monthly Medium Once Medium Annually in spring Medium Quarterly Annually (weekly during EWA) Every 3 years High Every 3 years Low Frequency Frequency Blue-green algae species and biovolume. and species algae Blue-green Phytoplankton species. Turbidity. Nutrients (nitrogen and phosphorus). Salinity. DO. pH. Grain size carbon and nutrient levels Total organic Presence or absence and abundance of and abundance or absence Presence native species. of and abundance or absence Presence species. introduced Taxa presence or absence. Abundance. (if available). score Observed or expected Population size. Habitat conditions. Number of tadpoles and metamorphoses. Number of species. Population size. Habitat conditions. Number of species. Population size. Sedimentation rate trend. Once Medium Indicator/Measure Establish baseline conditions. conditions. Establish baseline Set LACs. conditions. Establish baseline Set LACs. Objectives Objectives of native fish. Identify refugia for fish in the which system from Murrumbidgee they can migrate. Set LACs. changes. Detect impacts. Assess Set LACs. changes. Detect impacts. Assess impacts. Assess changes. Detect impacts. Assess Set LACs. Set LACs. Phytoplankton Set LACs. Phytoplankton Set Physico-chemical parameters Sediment quality Establish baseline conditions. Monitoring component Native fish Establish the habitat requirements Macroinvertebrates condition. Establish baseline Southern bell frog Set LACs. species Threatened Establish baseline. Other fauna Establish baseline. rate Sedimentation conditions. Establish baseline Ecological character Biological: phytoplankton Water Quality Sediment

92 Description of wetland ecological character Low Priority Priority Derive from hydrological and water quality Event based High Ongoing Medium Ongoing Biannually Low Event based High Frequency Frequency Total phosphorus. Total nitrogen. Water volume. Water volume. Delivery time. Inundation extent, depth and duration. No of vehicles. No of vehicles. or tents. No of campsites Extent. Rate of spread over within habitat. Water volume. Delivery time. Inundation extent, depth and duration. Indicator/Measure No of tourists. No of tourists. Assess impacts. impacts. Assess Assess impact. impact. Assess Fulfill legal obligations. Objectives Objectives Detect change. impacts. Assess impact. Assess Fulfill legal obligations. Environmental water allocation Monitoring component Recreation activity Assess impacts. weed Introduced invasion Nutrient loading change. Detect Environmental water allocation Ecological character Human intervention

Yanga National Park 93 11 Communication, education and public awareness messages

The only way to maintain the ecological character of Yanga National Park and other parts of the Lowbidgee floodplain (by reducing the loss of biodiversity and protecting habitats) is to gain the collaboration and cooperation of individuals, organisations and community groups to act on threats to the sites. Communication, education and public awareness (CEPA) plays an important role in developing and forging this collaboration and change in society. The multisectoral nature of conservation and management issues has led to the development of complex and often fragmented programs and action plans, with many agencies responsible for different parts of the problem. Responsible government departments require collaboration from other government organisations at national, state, regional and local level, and even internationally.

CEPA is the means to set up enabling conditions for collaboration so that policies, incentives and regulations across sectors encourage wetland conservation and wise use. CEPA develops the relationships and learning processes underpinning innovation in institutions and organisations. This process of change entails much more than releasing information through reports and memos. Aside from other government departments, wetland conservation needs support at varying times and places from NGOs, Indigenous peoples, business and industry, scientists, farmers and fishing associations, women’s groups, youth, consumer associations and community-based groups. To work with these different groups, CEPA is crucial to building trust, understanding and shared agreements for action and to reduce conflict.

11.1 Major CEPA activities for Yanga National Park

A number of CEPA activities in Yanga National Park in recent years have greatly increased public awareness of the environmental significance of the site: the acquisition of Yanga Station in 2005 by the NSW Government and subsequent gazettal as a national park in 2007 the evolution of Yanga National Park as a major focus for research on lowland floodplain ecology in NSW; major projects include: Z response of the southern bell frog to EWA Z historical extent and condition of major vegetation types in Yanga National Park Z hydrodynamic and hydrological modelling for the Lowbidgee floodplain Z waterbirds and fish survey and their responses to EWA Z trophic dynamics and organic matter and response to EWA Z surface water and groundwater gauging network. a number of infrastructure projects to improve EWA management, including the construction of a new bridge and regulator at Two Bridges Swamp a series of workshops bringing together park managers, river managers, wetland scientists and local landowners the employment of local people in Yanga National Park.

94 Description of wetland ecological character 11.2 Important CEPA messages Yanga National Park is a biodiversity hotspot within the arid and semi-arid south- eastern Australia region providing a mosaic of habitats made up of lowland floodplain forests and woodlands, large lakes and temporary wetlands for 20 threatened animal species and four threatened plant species. Yanga National Park contains one of the largest river red gum forests in the Murray– Darling Basin, comprising around 22,000 hectares and providing a unique opportunity to maintain a connected, organised and functioning ecosystem within the NSW Riverina bioregion where fragmentation and isolation are the major stressors for biological conservation. Historically, the Yanga floodplain supported a large number of waterbird colonies. Considering the widespread and dramatic decline in waterbird numbers in the Murray–Darling Basin in recent years, Yanga and other parts of the Lowbidgee floodplain provide important waterbird breeding sites. The natural attractions and terrain in Yanga National Park make it ideal for recreational opportunities such as camping, walking, cycling, driving tours and wildlife observation. Alteration of flood regimes is the single most significant factor contributing to the degradation of Yanga National Park; re-establishing natural flood regimes is the key to the maintenance, rejuvenation and rehabilitation the ecosystem function of the floodplain.

Yanga National Park 95 Appendix 1 Plant species in Yanga National Park

Family Scientific name Common name Status Aizoaceae Mesembryanthemum nodiflorum* Small ice plant Aizoaceae Disphyma crassifolium subsp. clavellatum Aizoaceae Psilocaulon tenue* Wiry noon-flower Alismataceae Damasonium minus Starfruit Amaranthaceae Alternanthera denticulata Lesser joyweed Amaranthaceae Ptilotus nobilis Yellowtails Amaranthaceae Alternanthera spp. Amaranthaceae Ptilotus exaltatus var. exaltatus Tall mulla mulla P Anacardiaceae Schinus areira* Pepper tree Apiaceae Daucus glochidiatus Native carrot Anthericaceae Thysanotus baueri Asphodelaceae Bulbine bulbosa Bulbine lily Asphodelaceae Bulbine semibarbata Wild onion Asteraceae Acroptilon repens* Creeping knapweed Asteraceae Angianthus brachypappus Spreading cup-flower Asteraceae Aster subulatus* Wild aster Asteraceae Brachyscome ciliaris Variable daisy Asteraceae Brachyscome basaltica var. gracilis Swamp daisy Asteraceae Brachyscome dentata Asteraceae Brachyscome lineariloba Hard-headed daisy Asteraceae Calocephalus sonderi Pale beauty-heads Asteraceae Calotis cuneifolia Purple burr-daisy Asteraceae Calotis hispidula Bogan flea Asteraceae Calotis scabiosifolia Rough burr-daisy Asteraceae Calotis scabiosifolia var. scabiosifolia Asteraceae Calotis hispidula Bogan flea Winged slender Asteraceae Carduus tenuiflorus* thistle Asteraceae Centaurea melitensis* Maltese cockspur Asteraceae Centipeda crateriformis subsp. compacta Common Asteraceae Centipeda cunninghamii sneezeweed Spreading Asteraceae Centipeda minima sneezeweed Asteraceae Centipeda thespidioides Desert sneezeweed Asteraceae Chrysocephalum apiculatum Common everlasting Asteraceae Chrysocephalum semipapposum Clustered everlasting Asteraceae Cirsium vulgare* Spear thistle Asteraceae Cotula coronopifolia* Water buttons Asteraceae Cynara cardunculus subsp. cardunculus* Asteraceae Cynara cardunculus subsp. flavescens* Asteraceae Gnephosis tenuissima Asteraceae Eclipta platyglossa Asteraceae Euchiton sphaericus

96 Description of wetland ecological character Family Scientific name Common name Status Asteraceae Helminthotheca echioides* Ox-tongue Asteraceae Hypochaeris glabra* Smooth catsear Asteraceae Leiocarpa websteri Asteraceae Leucochrysum albicans var. tricolor Asteraceae Minuria leptophylla Asteraceae Minuria cunninghamii Asteraceae Minuria integerrima Asteraceae Olearia lepidophylla Asteraceae Onopordum acaulon* Stemless thistle Asteraceae Picris hieracioides* Hawkweed picris Asteraceae Picris spp. Asteraceae Pycnosorus pleiocephalus P Asteraceae Rhodanthe corymbiflora Small white sunray Common white Asteraceae Rhodanthe floribunda P sunray Asteraceae Rhodanthe pygmaea Pigmy sunray Asteraceae Rhodanthe stuartiana Asteraceae Rhodanthe tietkensii Asteraceae Senecio cunninghamii Asteraceae Senecio cunninghamii var. cunninghamii Asteraceae Senecio glossanthus Asteraceae Senecio lautus subsp. dissectifolius Asteraceae Senecio runcinifolius Tall groundsel Asteraceae Sonchus asper subsp. glaucescens* Prickly sowthistle Asteraceae Sonchus oleraceus* Common sowthistle Asteraceae Vittadinia cuneata var. hirsuta Asteraceae Vittadinia gracilis Noogoora (cockle) Asteraceae Xanthium occidentale* burr Asteraceae Xanthium spinosum* Bathurst burr Azollaceae Azolla filiculoides Boraginaceae Echium plantagineum* Patterson's curse Boraginaceae Halgania andromedifolia Smooth halgania Boraginaceae Heliotropium curassavicum* Smooth heliotrope Boraginaceae Heliotropium europaeum* Common heliotrope Boraginaceae Heliotropium supinum* Prostrate heliotrope Boraginaceae Plagiobothrys plurisepaleus Brassicaceae Alyssum linifolium* Flax-leaf alyssum Brassicaceae Brassica tournefortii* Mediterranean turnip Brassicaceae Cuphonotus humistratus Brassicaceae Harmsiodoxa blennodioides Brassicaceae Lepidium fasciculatum Brassicaceae Lepidium monoplocoides Winged peppercress E Brassicaceae Sisymbrium irio* London rocket Brassicaceae Phlegmatospermum cochlearinum Oval-podded cress Brassicaceae Rorippa eustylis

Yanga National Park 97 Family Scientific name Common name Status Brassicaceae Rorippa laciniata Brassicaceae Sisymbrium erysimoides Smooth mustard Brassicaceae Stenopetalum sphaerocarpum Cactaceae Opuntia stricta* Campanulaceae Wahlenbergia fluminalis River bluebell Campanulaceae Wahlenbergia luteola Campanulaceae Wahlenbergia spp. Caryophyllaceae Spergularia diandra* Lesser sandspurry Caryophyllaceae Spergularia moorei* Caryophyllaceae Spergularia rubra* Sandspurry Casuarinaceae Casuarina cristata Belah Casuarinaceae Casuarina pauper Belah Chenopodiaceae Atriplex eardleyae Chenopodiaceae Atriplex leptocarpa Slender-fruit saltbush Chenopodiaceae Atriplex lindleyi Chenopodiaceae Atriplex nummularia Old man saltbush Chenopodiaceae Atriplex pseudocampanulata Chenopodiaceae Atriplex pumilio Chenopodiaceae Atriplex semibaccata Creeping saltbush Chenopodiaceae Atriplex spp. Chenopodiaceae Atriplex suberecta Chenopodium desertorum subsp. Chenopodiaceae desertorum Chenopodiaceae Chenopodium nitrariaceum Nitre goosefoot Chenopodiaceae Chenopodium pumilio Small crumbweed Chenopodiaceae Dissocarpus paradoxus Cannonball burr Chenopodiaceae Einadia nutans Climbing saltbush Chenopodiaceae Enchylaena tomentosa Ruby saltbush Chenopodiaceae Maireana astrotricha Low bluebush Chenopodiaceae Maireana brevifolia Chenopodiaceae Maireana erioclada Chenopodiaceae Maireana georgei Chenopodiaceae Maireana pentagona Hairy bluebush Chenopodiaceae Maireana pyramidata Black bluebush Chenopodiaceae Maireana sedifolia Pearl bluebush Chenopodiaceae Maireana spp. Chenopodiaceae Malacocera tricornis Soft horns Chenopodiaceae Osteocarpum acropterum Chenopodiaceae Osteocarpum acropterum var. deminuta Chenopodiaceae Osteocarpum spp. Chenopodiaceae Rhagodia spinescens Thorny saltbush Chenopodiaceae Rhagodia ulicina Chenopodiaceae Salsola kali var. kali Chenopodiaceae Sclerolaena brachyptera Chenopodiaceae Sclerolaena birchii Galvinized burr Chenopodiaceae Sclerolaena diacantha Grey copperburr

98 Description of wetland ecological character Family Scientific name Common name Status Chenopodiaceae Sclerolaena muricata Black rolypoly Chenopodiaceae Sclerolaena muricata var. villosa Chenopodiaceae Sclerolaena obliquicuspis Chenopodiaceae Sclerolaena obliquicuspis Chenopodiaceae Sclerolaena tricuspis Giant redburr Chenopodiaceae Sclerostegia tenuis Convolvulaceae Cressa australis Crassulaceae Crassula colorata Cyperaceae Carex appressa Tall sedge Cyperaceae Cyperus gymnocaulos Cyperaceae Eleocharis acuta Common spike rush Cyperaceae Eleocharis pusilla Cyperaceae Eleocharis sphacelata Tall spike rush Cyperaceae Eleocharis spp. Eriocaulaceae Eriocaulon australasicum Austral pipewort E Euphorbiaceae Chamaesyce dallachyana Euphorbiaceae Chamaesyce drummondii Caustic weed Euphorbiaceae Phyllanthus lacunarius Fabaceae Senna form taxon 'zygophylla' Fabaceae Astragalus hamosus* Yellow milk-vetch Fabaceae Cullen pallidum Fabaceae Daviesia genistifolia Broom bitter pea Fabaceae Lotus cruentus Red-flowered lotus Fabaceae Medicago minima* Woolly burr medic Fabaceae Medicago polymorpha* Burr medic Fabaceae Medicago spp.* Fabaceae Medicago truncatula* Barrel medic Fabaceae Melilotus indicus Hexham scent Fabaceae Swainsona murrayana Slender Darling pea V Fabaceae Swainsona phacoides Fabaceae Acacia melvillei Yarran Fabaceae Acacia oswaldii Miljee Fabaceae Acacia pendula Boree Fabaceae Acacia salicina Cooba Fabaceae Acacia stenophylla River cooba Fabaceae Acacia victoriae subsp. victoriae Elegant wattle Fumariaceae Fumaria spp.* Gentianaceae Centaurium spicatum Spike centaury Geraniaceae Pelargonium australe Native storksbill Goodeniaceae Goodenia fascicularis Goodeniaceae Goodenia glauca Goodeniaceae Goodenia heteromera Goodeniaceae Goodenia pusilliflora Goodeniaceae Goodenia spp. Haloragaceae Haloragis aspera

Yanga National Park 99 Family Scientific name Common name Status Haloragaceae Myriophyllum caput-medusae Cat-tail Common water Haloragaceae Myriophyllum propinquum milfoil Haloragaceae Myriophyllum verrucosum Red water milfoil Iridaceae Romulea rosea var. australis* Onion grass Hydrocharitaceae Vallisneria gigantea Eelweed Juncaceae Juncus acutus subsp. acutus* Sharp rush Juncaceae Juncus aridicola Juncaceae Juncus articulatus* Juncaceae Juncus flavidus Juncaceae Juncus radula Juncaceae Juncus spp. Lamiaceae Ajuga australis Austral bugle Lamiaceae Marrubium vulgare* Horehound Lamiaceae Westringia rigida Stiff westringia Lobeliaceae Pratia concolor Poison pratia Loranthaceae Amyema quandang var. quandang Loranthaceae Amyema spp. Lythraceae Lythrum hyssopifolia Hyssop loosestrife Malvaceae Hibiscus sturtii var. sturtii Malvaceae Lawrencia squamata Malvaceae Malva australiana Native hollyhock Malvaceae Malva nicaeensis* Mallow of Nice Small-flowered Malvaceae Malva parviflora* mallow Malvaceae Malva spp.* Malvaceae Sida corrugata Malvaceae Sida intricata Malvaceae Sida trichopoda Marsileaceae Marsilea costulifera Marsileaceae Marsilea drummondii Common nardoo Menyanthaceae Nymphoides crenata Wavy marshwort Myoporaceae Eremophila deserti Turkeybush Myoporaceae Eremophila longifolia Emu bush Myoporaceae Myoporum platycarpum subsp. platycarpum Myrtaceae Eucalyptus camaldulensis River red gum Myrtaceae Eucalyptus dumosa White mallee Myrtaceae Eucalyptus gracilis subsp. gracilis Myrtaceae Eucalyptus largiflorens Black box Myrtaceae Eucalyptus oleosa subsp. oleosa Red mallee Myrtaceae Eucalyptus socialis Red mallee Myrtaceae Melaleuca lanceolata Nitrariaceae Nitraria billardierei Dillon bush Nyctaginaceae Boerhavia dominii Tarvine Oleaceae Jasminum lineare Desert jasmine Onagraceae Epilobium hirtigerum

100 Description of wetland ecological character Family Scientific name Common name Status Onagraceae Ludwigia peploides subsp. montevidensis Water primrose Oxalidaceae Oxalis perennans Plantaginaceae Plantago drummondii Plantaginaceae Plantago turrifera Plumbaginaceae Limonium lobatum* Winged sea lavender Perennial sea Plumbaginaceae Limonium sinuatum* lavender Poaceae Alopecurus geniculatus* Marsh foxtail Poaceae Amphibromus spp. Poaceae Austrodanthonia caespitosa Ringed wallaby grass Poaceae Austrostipa drummondii Poaceae Austrostipa nitida Poaceae Austrostipa nodosa Poaceae Austrostipa scabra subsp. scabra Poaceae Bromus catharticus* Praire grass Poaceae Bromus rubens* Red brome Poaceae Chloris truncata Windmill grass Poaceae Dactyloctenium radulans Button grass Poaceae Elymus scaber Poaceae Enneapogon avenaceus Bottle washers Poaceae Enteropogon acicularis Poaceae Eragrostis australasica Canegrass Poaceae Eragrostis cilianensis* Stinkgrass Poaceae Eragrostis dielsii Mallee lovegrass Poaceae Eragrostis setifolia Neverfail Poaceae Hordeum leporinum* Barley grass Poaceae Hordeum marinum* Sea barley grass Poaceae Lachnagrostis filiformis Poaceae Lamarckia aurea* Goldentop Poaceae Lolium perenne* Perennial ryegrass Poaceae Paspalidium jubiflorum Warrego grass Poaceae Paspalum distichum Water couch Poaceae Phalaris minor* Lesser canary grass Poaceae Phalaris paradoxa* Paradoxa grass Poaceae Phragmites australis Common reed Poaceae Poa fordeana Poaceae Polypogon monspeliensis* Annual beardgrass Poaceae Schismus barbatus* Arabian grass Poaceae Sporobolus caroli Fairy grass Poaceae Triodia scariosa Porcupine grass Poaceae Vulpia myuros f. megalura* Polygonaceae Muehlenbeckia florulenta Lignum Polygonaceae Muehlenbeckia horrida Polygonaceae Persicaria decipiens Slender knotweed Polygonaceae Persicaria lapathifolia Pale knotweed Polygonaceae Persicaria orientalis* Princes feathers

Yanga National Park 101 Family Scientific name Common name Status Polygonaceae Persicaria prostrata Creeping knotweed Polygonaceae Persicaria spp. Polygonaceae Polygonum arenastrum* Wireweed Polygonaceae Polygonum plebeium Small knotweed Polygonaceae Rumex crispus* Curled dock Polygonaceae Rumex spp. Polygonaceae Rumex crystallinus Shiny dock Potamogetonaceae Potamogeton crispus Curly pondweed Potamogetonaceae Potamogeton sulcatus Potamogetonaceae Potamogeton tricarinatus Floating pondweed Proteaceae Hakea leucoptera Needlewood Proteaceae Hakea leucoptera subsp. leucoptera Proteaceae Hakea tephrosperma Hooked needlewood Ranunculaceae Ranunculus inundatus River buttercup Ranunculaceae Ranunculus lappaceus Common buttercup Ranunculaceae Ranunculus pentandrus Ranunculaceae Ranunculus pentandrus var. platycarpus Ranunculaceae Ranunculus sceleratus* Celery buttercup Ranunculaceae Ranunculus spp. Ranunculaceae Ranunculus undosus Rubiaceae Asperula conferta Common woodruff Western rosewood, Sapindaceae Alectryon oleifolius bonaree Scrophulariaceae Gratiola pedunculata Scrophulariaceae Stemodia florulenta Bluerod Solanaceae Datura inoxia* Downy thornapple Solanaceae Lycium ferocissimum* African boxthorn Solanaceae Nicotiana glauca* Tree tobacco Solanaceae Solanum esuriale Quena Menindee Solanaceae Solanum karsense V nightshade Black-berry Solanaceae Solanum nigrum* nightshade Solanaceae Solanum spp. Thymelaeaceae Pimelea microcephala subsp. microcephala Broad-leaved Typhaceae Typha orientalis cumbungi Urticaceae Urtica urens* Small nettle Zygophyllaceae Zygophyllum ammophilum Sand twinleaf Zygophyllaceae Zygophyllum aurantiacum Shrubby twinleaf Zygophyllaceae Zygophyllum crenatum Lobed twinleaf Zygophyllaceae Zygophyllum glaucum Pale twinleaf Zygophyllaceae Zygophyllum iodocarpum Violet twinleaf

* Exotic species P, protected; E, endangered; V, vulnerable

102 Description of wetland ecological character Appendix 2 Bird species in Yanga National Park

Family Scientific name Common name Status Meliphagidae Acanthagenys rufogularis Spiny-cheeked honeyeater P Acanthizidae Acanthiza apicalis Inland thornbill P Acanthizidae Acanthiza chrysorrhoa Yellow-rumped thornbill P Acanthizidae Acanthiza nana Yellow thornbill P Acanthizidae Acanthiza uropygialis Chestnut-rumped thornbill P Accipitridae Accipiter cirrocephalus Collared sparrowhawk P Accipitridae Accipiter fasciatus Brown goshawk P Sylviidae Acrocephalus australis Australian reed-warbler P Aegothelidae Aegotheles cristatus Australian owlet-nightjar P Alcedinidae Alcedo azurea Azure kingfisher P Anatidae Anas castanea Chestnut teal P Anatidae Anas gracilis Grey teal P Anatidae Anas rhynchotis Australasian shoveler P Anatidae Anas superciliosa Pacific black duck P Anhingidae Anhinga melanogaster Darter P Anatidae Anser sp.* Domestic goose U Anseranatidae Anseranas semipalmata Magpie goose V Meliphagidae Anthochaera carunculata Red wattlebird P Motacillidae Anthus australis Australian pipit P Acanthizidae Aphelocephala leucopsis Southern whiteface P Apodidae Apus pacificus Fork-tailed swift P Accipitridae Aquila audax Wedge-tailed eagle P Ardeidae Ardea alba Great egret P Ardeidae Ardea intermedia Intermediate egret P Ardeidae Ardea pacifica White-necked heron P Ardeidae Ardea/Egretta sp. Unidentified egret P Artamidae Artamus cinereus Black-faced woodswallow P Artamidae Artamus cyanopterus Dusky woodswallow P Artamidae Artamus leucorynchus White-breasted woodswallow P Artamidae Artamus personatus Masked woodswallow P Artamidae Artamus superciliosus White-browed woodswallow P Anatidae Aythya australis Hardhead P Psittacidae Barnardius zonarius barnardi Mallee ringneck P Anatidae Biziura lobata Musk duck P Ardeidae Botaurus poiciloptilus Australasian bittern V Ardeidae Bubulcus ibis Cattle egret P Burhinidae Burhinus grallarius Bush stone-curlew E Cacatuidae Cacatua galerita Sulphur-crested cockatoo P Cacatuidae Cacatua sanguinea Little corella P Scolopacidae Calidris acuminata Sharp-tailed sandpiper P Cuculidae Chalcites basalis Horsfield's bronze-cuckoo P Cuculidae Chalcites osculans Black-eared cuckoo P Charadriidae Charadrius ruficapillus Red-capped plover P

Yanga National Park 103 Family Scientific name Common name Status Anatidae Chenonetta jubata Australian wood duck P Hirundinidae Cheramoeca leucosterna White-backed swallow P Ptilonorhynchidae Chlamydera maculata Spotted bowerbird P Laridae Chlidonias hybridus Whiskered tern P Sylviidae Cincloramphus cruralis Brown songlark P Sylviidae Cincloramphus mathewsi Rufous songlark P Eupetidae Cinclosoma castanotus Chestnut quail-thrush V Accipitridae Circus approximans Swamp harrier P Accipitridae Circus assimilis Spotted harrier P Cisticolidae Cisticola exilis Golden-headed cisticola P Recurvirostridae Cladorhynchus leucocephalus Banded stilt P Climacteridae Climacteris picumnus Brown treecreeper V Pachycephalidae Colluricincla harmonica Grey shrike-thrush P Columbidae Columba livia* Rock dove U Campephagidae Coracina maxima Ground cuckoo-shrike P Campephagidae Coracina novaehollandiae Black-faced cuckoo-shrike P Campephagidae Coracina papuensis White-bellied cuckoo-shrike P Corcoracidae Corcorax melanorhamphos White-winged chough P Corvidae Corvus bennetti Little crow P Corvidae Corvus coronoides Australian raven P Corvidae Corvus mellori Little raven P Phasianidae Coturnix pectoralis Stubble quail P Phasianidae Coturnix ypsilophora Brown quail P Artamidae Cracticus nigrogularis Pied butcherbird P Cuculidae Cuculus pallidus Pallid cuckoo P Anatidae Cygnus atratus Black swan P Alcedinidae Dacelo novaeguineae Laughing kookaburra P Neosittidae Daphoenositta chrysoptera Varied sittella P Anatidae Dendrocygna eytoni Plumed whistling-duck P Dicaeidae Dicaeum hirundinaceum Mistletoebird P Casuariidae Dromaius novaehollandiae Emu P Ardeidae Egretta garzetta Little egret P Ardeidae Egretta novaehollandiae White-faced heron P Accipitridae Elanus axillaris Black-shouldered kite P Charadriidae Elseyornis melanops Black-fronted dotterel P Meliphagidae Entomyzon cyanotis Blue-faced honeyeater P Cacatuidae Eolophus roseicapillus Galah P Meliphagidae Epthianura albifrons White-fronted chat P Meliphagidae Epthianura tricolor Crimson chat P Charadriidae Erythrogonys cinctus Red-kneed dotterel P Caprimulgidae Eurostopodus argus Spotted nightjar P Falconidae Falco berigora Brown falcon P Falconidae Falco cenchroides Nankeen kestrel P Falconidae Falco longipennis Australian hobby P Falconidae Falco peregrinus Peregrine falcon P

104 Description of wetland ecological character Family Scientific name Common name Status Falconidae Falco subniger Black falcon P Pachycephalidae Falcunculus frontatus Eastern shrike-tit P Rallidae Fulica atra Eurasian coot P Scolopacidae Gallinago hardwickii Latham's snipe P Rallidae Gallinula tenebrosa Dusky moorhen P Rallidae Gallinula ventralis Black-tailed native-hen P Rallidae Gallirallus philippensis Buff-banded rail P Columbidae Geopelia placida Peaceful dove P Acanthizidae Gerygone fusca Western gerygone P Dicruridae Grallina cyanoleuca Magpie-lark P Meliphagidae Grantiella picta Painted honeyeater V Artamidae Gymnorhina tibicen Australian magpie P Accipitridae Haliaeetus leucogaster White-bellied sea-eagle P Accipitridae Haliastur sphenurus Whistling kite P Accipitridae Hieraaetus morphnoides Little eagle P Recurvirostridae Himantopus himantopus Black-winged stilt P Hirundinidae Hirundo neoxena Welcome swallow P Ardeidae Ixobrychus minutus Little bittern P Campephagidae Lalage tricolor White-winged triller P Laridae Larus novaehollandiae Silver gull P Meliphagidae Lichenostomus leucotis White-eared honeyeater P Meliphagidae Lichenostomus ornatus Yellow-plumed honeyeater P Meliphagidae Lichenostomus virescens Singing honeyeater P Accipitridae Lophoictinia isura Square-tailed kite V Anatidae Malacorhynchus membranaceus Pink-eared duck P Maluridae Malurus cyaneus Superb fairy-wren P Maluridae Malurus lamberti Variegated fairy-wren P Maluridae Malurus leucopterus White-winged fairy-wren P Maluridae Malurus splendens Splendid fairy-wren P Meliphagidae Manorina flavigula Yellow-throated miner P Meliphagidae Manorina melanocephala Noisy miner P Sylviidae Megalurus gramineus Little grassbird P Petroicidae Melanodryas cucullata Hooded robin V Meliphagidae Melithreptus brevirostris Brown-headed honeyeater P Psittacidae Melopsittacus undulatus Budgerigar P Meropidae Merops ornatus Rainbow bee-eater P Petroicidae Microeca fascinans Jacky winter P Accipitridae Milvus migrans Black kite P Alaudidae Mirafra javanica Horsfield's bushlark P Dicruridae Myiagra inquieta Restless flycatcher P Psittacidae Neophema chrysostoma Blue-winged parrot P Strigidae Ninox boobook Southern boobook P Strigidae Ninox connivens Barking owl V Psittacidae Northiella haematogaster Blue bonnet P Ardeidae Nycticorax caledonicus Nankeen night heron P

Yanga National Park 105 Family Scientific name Common name Status Cacatuidae Nymphicus hollandicus Cockatiel P Columbidae Ocyphaps lophotes Crested pigeon P Pachycephalidae Oreoica gutturalis Crested bellbird P Oriolidae Oriolus sagittatus Olive-backed oriole P Anatidae Oxyura australis Blue-billed duck V Pachycephalidae Pachycephala pectoralis Golden whistler P Pachycephalidae Pachycephala rufiventris Rufous whistler P Pardalotidae Pardalotus punctatus Spotted pardalote P Pardalotidae Pardalotus punctatus Yellow-rumped pardalote P Pardalotidae Pardalotus striatus Striated pardalote P Passeridae Passer domesticus* House sparrow U Pelecanidae Pelecanus conspicillatus Australian pelican P Charadriidae Peltohyas australis Inland dotterel P Hirundinidae Petrochelidon ariel Fairy martin P Hirundinidae Petrochelidon nigricans Tree martin P Petroicidae Petroica goodenovii Red-capped robin P Petroicidae Petroica phoenicea Flame robin P Phalacrocoracidae Phalacrocorax carbo Great cormorant P Phalacrocoracidae Phalacrocorax melanoleucos Little pied cormorant P Phalacrocoracidae Phalacrocorax sulcirostris Little black cormorant P Phalacrocoracidae Phalacrocorax varius Pied cormorant P Columbidae Phaps chalcoptera Common bronzewing P Meliphagidae Philemon citreogularis Little friarbird P Meliphagidae Phylidonyris albifrons White-fronted honeyeater P Threskiornithidae Platalea flavipes Yellow-billed spoonbill P Threskiornithidae Platalea regia Royal spoonbill P Psittacidae Platycercus adscitus eximius Eastern rosella P Psittacidae Platycercus elegans Crimson rosella P Psittacidae Platycercus elegans flaveolus Yellow rosella P Meliphagidae Plectorhyncha lanceolata Striped honeyeater P Threskiornithidae Plegadis falcinellus Glossy ibis P Podargidae Podargus strigoides Tawny frogmouth P Podicipedidae Podiceps cristatus Great crested grebe P Podicipedidae Poliocephalus poliocephalus Hoary-headed grebe P Polytelis anthopeplus Regent parrot Psittacidae E monarchoides (eastern subspecies) Psittacidae Polytelis swainsonii Superb parrot V Pomatostomidae Pomatostomus ruficeps Chestnut-crowned babbler P Pomatostomidae Pomatostomus superciliosus White-browed babbler P Pomatostomus temporalis Grey-crowned babbler Pomatostomidae V temporalis (eastern subspecies) Rallidae Porphyrio porphyrio Purple swamphen P Rallidae Porzana fluminea Australian spotted crake P Rallidae Porzana pusilla Baillon's crake P Psittacidae Psephotus haematonotus Red-rumped parrot P Psittacidae Psephotus varius Mulga parrot P

106 Description of wetland ecological character Family Scientific name Common name Status Acanthizidae Pyrrholaemus brunneus Redthroat V Recurvirostridae Recurvirostra novaehollandiae Red-necked avocet P Dicruridae Rhipidura albiscapa Grey fantail P Dicruridae Rhipidura leucophrys Willie wagtail P Painted snipe Rostratulidae Rostratula benghalensis australis E (Australian subspecies) Podicipedidae small grebe sp. Small grebe P Charadriidae small wader sp. Small waders P Acanthizidae Smicrornis brevirostris Weebill P Laridae Sterna caspia Caspian tern P Laridae Sterna nilotica Gull-billed tern P Anatidae Stictonetta naevosa Freckled duck V Glareolidae Stiltia isabella Australian pratincole P Artamidae Strepera versicolor Grey currawong P Corcoracidae Struthidea cinerea Apostlebird P Sturnidae Sturnus vulgaris* Common starling U Podicipedidae Tachybaptus novaehollandiae Australasian grebe P Anatidae Tadorna tadornoides Australian shelduck P Estrildidae Taeniopygia guttata Zebra finch P Threskiornithidae Threskiornis molucca Australian white ibis P Threskiornithidae Threskiornis spinicollis Straw-necked ibis P Alcedinidae Todiramphus pyrrhopygia Red-backed kingfisher P Alcedinidae Todiramphus sanctus Sacred kingfisher P Psittacidae Trichoglossus haematodus Rainbow lorikeet P Scolopacidae Tringa nebularia Common greenshank P Scolopacidae Tringa stagnatilis Marsh sandpiper P Muscicapidae Turdus merula* Eurasian blackbird U Turnicidae Turnix varia Painted button-quail P Turnicidae Turnix velox Little button-quail P Tytonidae Tyto alba Barn owl P Charadriidae Vanellus miles Masked lapwing P Charadriidae Vanellus tricolor Banded lapwing P

P, protected; E, endangered; U, introduced; V, vulnerable.

Yanga National Park 107 References

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