Gwydir Waterbird and Fish Habitat Study

Final report

Cover photographs Front page: Boyanga Waterhole, Gingham Watercourse (Credit: J. Spencer); Golden perch, Mehi River (Credit: J. Spencer); Great egret (Credit: M. Carpenter).

Citation This report can be cited as follows: Spencer, J.A., Heagney, E.C. and Porter, J.L. 2010. Final report on the Gwydir waterbird and fish habitat study. NSW Wetland Recovery Program. Rivers and Wetlands Unit, Department of Environment, Climate Change and Water NSW and University of New South Wales, Sydney.

Acknowledgments Funding for this project was provided by the NSW Government and the Australian Government’s Water for the Future – Water Smart Australia program. Richard Allman, Sharon Bowen, Kirsty Brennan, Ben Daly, Simon Hunter, Jordan Iles, Jeff Kelleway, Lisa Knowles, Yoshi Kobayashi, Natalia Perera, Shannon Simpson, Rachael Thomas (DECCW), Neal Foster (NOW), Gus Porter and Ainslee Lions provided field support. Thanks to our pilots Richard Byrne (DECCW) and James Rainger (Fleet Helicopters) for their assistance with aerial waterbird surveys. Daryl Albertson (DECCW), Neal Foster, Liz Savage and James Houlahan (Border Rivers–Gwydir CMA) and Glenn Wilson (UNE) gave advice on field site locations. Jennifer and Bruce Southeron (Old Dromana), Sam Kirkby (Bunnor), Howard Blackburn (Crinolyn), Bill Johnson (DECCW), Liz Savage (Border Rivers–Gwydir CMA), Neal Foster, Tara Schalk (NOW), Richard Ping Kee (Moree fishing club), Dick Cooper, Greg Clancy and the NSW Bird Atlassers contributed historical information on waterbird and fish populations in the Gwydir. Sue Powell (ANU) supplied information on the flooding history and flow data for the Gwydir Wetlands. Mark McGrouther and Sally Reader (Australian Museum, Sydney) assisted with the identification of fish species. Jennifer and Bruce Southeron (Old Dromana) kindly provided our accommodation and field station. Glenn Wilson, Neal Foster, Bill Johnson, Renee Shepherd and Daryl Albertson commented on a draft report. Many thanks to landowners in the Gwydir for allowing access to their properties.

Published by:

Department of Environment, Climate Change and Water NSW 59–61 Goulburn Street; PO Box A290 Sydney South 1232 Phone: (02) 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au

DECCW is pleased to allow this material to be reproduced in whole or in part, provided the meaning is unchanged, and its source, publisher and authorship are acknowledged.

ISBN 978 1 74232 812 6 DECCW 2010/508 June 2010

Printed on recycled paper

Contents

Summary ...... 6 Background ...... 6 Field surveys ...... 6 Recommendations for management ...... 7

1. Introduction ...... 8 1.1 Project background ...... 8 1.2 The Gwydir Wetlands ...... 11

2. Field surveys (2007–08) ...... 19 2.1 Methods ...... 19 2.2 Results ...... 27 2.3 Conclusions ...... 42

3. Water requirements for key species ...... 43 3.1 Waterbirds...... 43 3.2 Fish ...... 44 3.3 Implications for management ...... 50

4. Recommendations for management ...... 51 4.1 Priorities for rehabilitation ...... 51 4.2 Potential on-ground works ...... 57 4.3 Recommendations for monitoring ...... 58 4.4 Further research ...... 63

References ...... 64

Appendix 1: Species names ...... 69 Waterbird species recorded in the Gwydir Wetlands ...... 69 Fish species recorded in the Gwydir River catchment ...... 71 Freshwater turtles and invertebrates recorded during field surveys (2007–08) ...... 72

Appendix 2: Field site locations (2007–08) ...... 73 Waterbird ground survey sites ...... 73 Fish survey sites ...... 74 Waterbird aerial survey sites ...... 75 Waterbird ground survey sites ...... 77 Fish sampling sites on the Carole, Gingham and Lower Gwydir River channels ...... 79 Fish sampling sites on the Mehi and Gwydir River ...... 80

Appendix 3. Habitat requirements of selected waterbird species ...... 81

Final report on the Gwydir waterbird and fish habitat study 3

Tables

Table 1. Summary of project milestones and outcomes from the Gwydir waterbird and fish habitat study ...... 10 Table 2. Total counts of each waterbird species recorded in the Gwydir Wetlands during light aircraft aerial surveys in October 2007 (n = 40) and April 2008 (n = 48) ...... 30 Table 3. Mean (± s.e.) total counts of waterbirds recorded during ground surveys of the Gwydir Wetlands in October 2007 (n = 49) and April 2008 (n = 63) ...... 32 Table 4. Maximum counts of waterbird species recorded during ground counts in the Gwydir Wetlands in October 2007 (n = 49) and April 2008 (n = 63) ...... 33 Table 5. Total numbers of each fish species, turtles and invertebrates caught at each sampling site in the Gwydir Wetlands in November 2007 and March 2008 (n = 11) .....36 Table 6. Mean (± s.e.) standard length (centimetres) of fish species collected during field surveys in the Gwydir Wetlands (2007–08) (a) November 2007 and (b) March 2008 ...37 Table 7. Characteristics of fish survey sites in the Gwydir Wetlands (November 2007, March 2008) ...... 38 Table 8. Total number of juvenile fish caught at survey sites in the Gwydir Wetlands (March 2008; n = 11) ...... 40 Table 9. Life history and habitat requirements of fish species recorded in the Gwydir Wetlands ...... 47 Table 10. Threatened waterbird and fish species that have been recorded in the Gwydir Wetlands ...... 52 Table 11. Potential options for monitoring waterbird and fish populations and their habitats in the Gwydir Wetlands...... 60

Figures

Figure 1. Location of the Gwydir Wetlands, northern NSW ...... 13 Figure 2. Location of Ramsar sites and major weirs on the Gwydir River system ...... 14 Figure 3. Site locations for aerial surveys of waterbirds in the Gwydir Wetlands (October 2007, April 2008)...... 21 Figure 4. Sites surveyed during ground surveys for waterbirds in the Gwydir Wetlands (October 2007, April 2008)...... 22 Figure 5. Sampling locations for fish surveys in the Gwydir Wetlands (November 2007; March 2008)...... 25 Figure 6. Total daily rainfall and mean daily discharge for the Gwydir River from June 2007–May 2008 ...... 26 Figure 7. Total numbers of waterbirds recorded in the Gwydir system during light aircraft aerial surveys in October 2007 (n = 40) and April 2008 (n = 48) (n = number of survey sites) ...... 29 Figure 8. Reproductive status of adult bony bream collected from the Gwydir Wetlands (13–19 November 2007; n = 180) ...... 41 Figure 9. Historical locations of waterbird breeding habitat in the Gwydir Wetlands (1921–2005) ...... 56

4 Final report on the Gwydir waterbird and fish habitat study

Abbreviations

AEMP Adaptive Environmental Management Plan BOM Bureau of Meteorology CAMBA China–Australia Migratory Bird Agreement CMA Catchment Management Authority DECCW Department of Environment, Climate Change and Water NSW EPBC Commonwealth Environment Protection and Biodiversity Conservation Act 1999 I&I NSW Industry and Investment NSW IUCN International Union for Conservation of Nature JAMBA Japan-Australia Migratory Bird Agreement LiDAR Light Detection and Ranging (Optical remote sensing technology) MDB Murray–Darling Basin NOW NSW Office of Water pers. comm. personal communication ROKAMBA Republic of Korea–Australia Migratory Bird Agreement s.e. standard error TSC NSW Threatened Species Conservation Act 1995 UNE University of New England UNSW University of New South Wales WRP Wetland Recovery Program

Final report on the Gwydir waterbird and fish habitat study 5

Summary

Background

Parts of the Gwydir Wetlands are listed as internationally significant wetlands under the Ramsar Convention but are under ecological stress as a result of drought, and land and water management practices. The NSW Wetland Recovery Program supported a suite of science projects, including a waterbird and fish habitat study, to assist the recovery of the Gwydir Wetlands. The Gwydir waterbird and fish habitat study was proposed to provide an in-depth ecological investigation into the status of waterbird and fish populations in the Gwydir Wetlands. The NSW Wetland Recovery Program is jointly funded by the NSW Government and the Australian Government’s Water for the Future–Water Smart Australia program and is delivered in partnership by the Department of Environment, Climate Change and Water NSW, the NSW Office of Water, Industry and Investment NSW and the Central West and Border Rivers–Gwydir Catchment Management Authorities. The main outcome of the Gwydir waterbird and fish project was to provide baseline data on waterbird and fish assemblages in the Gwydir Wetlands. Key outcomes from this project include: • the compilation of historical records of waterbirds and fish • field surveys of waterbird and fish assemblages, and • recommendations for restoring and managing waterbird and fish habitat in the Gwydir Wetlands. Despite the lack of historical survey data documenting waterbirds and fish populations in the Gwydir Wetlands, at least 75 waterbird species and 12 native fish species have been recorded in the area. This includes nine threatened waterbird species and at least two threatened native fish that may have used the Gwydir Wetlands for part of their life cycle. The wetlands have supported a cattle and sheep grazing industry since the late 1830s but land development for dryland cropping and irrigation has been extensive since the 1970s. Regulation of inflows has reduced the frequency and duration of flood events and caused at least a 75 per cent decrease in the area of semi-permanent wetlands. Reduced inflows have caused declines in water quality, the health of wetland vegetation and in the diversity and numbers of native waterbird and fish species. Weirs and other barriers have also disrupted the movements and spawning patterns of native fish.

Field surveys

A combination of aerial and ground-based surveys were conducted to determine the distribution and abundance of waterbird species in the Gwydir Wetlands in October 2007 and April 2008. Surveys were concentrated on wetland habitats on the main channels and floodplains of the Lower Gwydir River, Gingham Watercourse, Mehi River and Carole Creek. Large farm storages were also surveyed on an ad hoc basis. During both survey periods, much of the floodplain was extremely dry and available water was confined to channels, floodplain waterholes and farm storages. The results of the aerial and ground surveys in 2007–08 indicated that numbers of waterbirds were very low in the Gwydir Wetlands and breeding activity was limited. In total, 45 waterbird

6 Final report on the Gwydir waterbird and fish habitat study

species were recorded, but waterbird assemblages were dominated by duck species, in particular Australian wood duck (Chenonetta jubata), plumed whistling duck (Dendrocygna eytoni) and grey teal (Anas gracilis). Fish surveys were conducted in the main channels in the Gwydir Wetlands in November 2007 and March 2008. Eleven in-channel sites were sampled during both survey periods and an additional five floodplain waterholes were surveyed in March 2008. Eleven native and three alien fish species were recorded. Bony bream (Nematalosa erebi), Australian smelt (Retropinnia semoni), carp gudgeons (Hypseleotris spp.) and Murray–Darling rainbowfish (Melanotanenia fluviatilis) were the most common species at the in-channel sites. Total numbers of alien fish were low, about 6–7 per cent of the total catch, and European carp (Cyprinus carpio) was the most common alien species. There was evidence of fish spawning and recruitment during both sampling periods. Larval stages of seven fish species were collected during spring surveys (November 2007) but juvenile fish were present during both survey periods. A high proportion of bony bream caught during the March 2008 surveys were juvenile fish (96 per cent of total catch). Spangled perch (Leiopotherapon unicolor) and Eastern gambusia (Gambusia holbrooki) colonised newly flooded waterholes on the Gingham and Lower Gwydir River floodplain in March 2008. About 30 adult carp (>30 centimetres) were caught at Jackson, on the Gingham Watercourse in November 2007. Many juvenile carp were caught at this site in March 2008. These observations suggest that parts of the Gingham Watercourse provide important spawning and nursery sites for carp.

Recommendations for management

Key recommendations for restoring and enhancing waterbird and native fish populations in the Gwydir Wetlands were to: • protect high priority waterbird and fish habitats • maintain connectivity between floodplain wetlands and the Lower Gwydir River and Gingham Watercourses • actively manage feral animals and plants • rehabilitate and create new waterbird breeding habitats • modify or remove barriers to fish passage • revegetate waterbird breeding habitat and riparian zones, and • support further monitoring and research of waterbirds and native fish populations and their habitats. Detailed recommendations and a list of potential on-ground works for restoring and maintaining waterbird and fish habitat are included herein.

Final report on the Gwydir waterbird and fish habitat study 7

1. Introduction

1.1 Project background

1.1.1 The NSW Wetland Recovery Program

This study was funded under the NSW Wetland Recovery Program (WRP) which consists of a suite of projects that aim to assist the recovery of the Gwydir Wetlands and the Macquarie Marshes. Parts of these wetlands are recognised as internationally significant wetlands under the Ramsar Convention but are currently under ecological stress as a result of drought, and land and water management practices. The WRP is jointly funded by the NSW Government and the Australian Government’s Water for the Future – Water Smart Australia program, delivered in partnership by the Department of Environment, Climate Change and Water NSW (DECCW), the NSW Office of Water (NOW), Industry and Investment NSW (I&I NSW) and the Central West and Border Rivers–Gwydir Catchment Management Authorities (CMAs). The WRP is designed to assist private landholders with wetland conservation alongside productive use of their land. While the WRP is focused on the Macquarie Marshes and Gwydir Wetlands, the projects undertaken in these two wetlands are intended to inform the development of recovery strategies for other important wetlands in NSW. The program focuses on developing Adaptive Environmental Management Plans for the Macquarie Marshes and Gwydir Wetlands, based on ecological characterisation; implementing infrastructure projects to improve water efficiencies in these wetlands; and projects which improve the overall management of the wetlands. DECCW-managed science projects funded by the WRP which are contributing to an ecological characterisation of the Gwydir Wetlands include: • LiDAR (light detection and ranging) surveys and products: to capture high resolution elevation and colour and multispectral imagery of the Gwydir Wetlands as part of a survey of 11,000 square kilometres of wetlands and floodplains in central-western and north-western NSW. LiDAR data and its products will be used to develop digital elevation models of the Gwydir Wetlands. • Inundation mapping: to map flood extent, frequency and duration from Landsat satellite imagery of the Gwydir Wetlands and other significant wetlands sampled across a 20-year period. • Trophic dynamics and ecosystem function study: to determine key food web pathways in floodplain wetlands, including the Gwydir Wetlands. • Waterbird and fish habitat study: to collate historical information and survey contemporary waterbird and fish assemblages in the Gwydir Wetlands. • Vegetation mapping: to create maps of the distribution of wetland vegetation and to assess the condition of key vegetation communities in the Gwydir Wetlands. • Land-use and grazing study: to review effects of grazing on wetland condition and measure the effect of grazing using established exclusion plots in the Gwydir Wetlands.

8 Final report on the Gwydir waterbird and fish habitat study

The Gwydir waterbird and fish habitat study was proposed to provide an in-depth ecological investigation into the status of waterbird and fish populations in the Gwydir Wetlands. The project was designed to deliver long-term benefits to the health of the Gwydir Wetlands by helping to identify key habitats that can be targeted for the delivery of environmental water in order to maintain the wetlands’ ecological function.

1.1.2 Project aims

The Gwydir waterbird and fish habitat study was designed to provide an understanding of the habitat requirements of waterbird and fish species in the Gwydir Wetlands by: • collating data on variability in waterbird and fish populations in the Gwydir Wetlands • surveying contemporary waterbird and fish assemblages and their habitats, and • relating waterbird and fish breeding success and recruitment to hydrological conditions.

1.1.3 Project outcomes

The main outcome of the Gwydir waterbird and fish project is baseline data on waterbird and fish assemblages in the Gwydir Wetlands. The project aimed to deliver a comprehensive data set on waterbird fish and assemblages, their geographic extent and recommendations for management. Data from this project and other research projects funded under WRP will provide information for an Adaptive Environmental Management Plan (AEMP) and a decision-support tool being developed for the Gwydir Wetlands. These outputs are designed to assist local managers with decision-making in the Gwydir system. This will deliver long-term benefits through better delivery of environmental water and improved flow regimes which will help to restore ecological function and maintain biodiversity in the Gwydir Wetlands.

1.1.4 Key performance indicators

Specific milestones were set for the Gwydir waterbird and fish habitat study at the start of the WRP. These milestones were described in an implementation strategy for the WRP. Work schedules for this science project were planned according to these milestones (see Table 1). Key deliverables for this project include compiling historical records of waterbirds and fish, and conducting spring and summer field surveys of waterbird and fish assemblages in the Gwydir Wetlands. A number of tasks were needed for the successful completion of this project.

Collation of historical records Local landowners were interviewed in May 2007 to gather information for the historical review of waterbird and fish populations and to select field sites. A draft version of the historical review was completed in June 2007. Landowners in the Gwydir, staff from the Border Rivers–Gwydir CMAs and Dick Cooper (NSW Bird Atlasers) were contacted to review the draft report. These comments were incorporated into the final report which was finalised in June 2008 (Spencer 2010).

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Field surveys Surveys of waterbirds and fish populations and their habitats were planned for spring and summer months in 2007–08. Dr John Porter (University of New South Wales, UNSW) was contracted to assist with aerial surveys of waterbirds in the Gwydir in October 2007 and April 2008. Aerial surveys for waterbirds were flown over the four main channels in the Gwydir Wetlands. A sub-sample of sites were visited during replicate ground counts of waterbird habitats. These surveys were used to ground-truth the aerial surveys (see Methods 2.1.1). Ms Elizabeth Heagney (UNSW) was contracted to assist with fish surveys. Surveys for fish were carried out in November 2007 and March 2008 (see Spencer 2007; Spencer 2008).

Table 1. Summary of project milestones and outcomes from the Gwydir waterbird and fish habitat study

Key Commonwealth Description Finish performance milestone date indicator 1 3 Draft report of historical records of waterbird June 07 and fish populations in the Gwydir Wetlands 2 4 Summary report of spring field surveys (Oct– Dec 07 Nov 2007) of waterbirds and fish in the Gwydir Wetlands (Spencer 2007) 3 6 Final report of historical records of waterbird June 08 and fish populations in the Gwydir Wetlands (Spencer 2010) 4 6 Summary report of summer field surveys June 08 (Mar–Apr 2008) of waterbirds and fish in the Gwydir Wetlands (Spencer 2008) 5 6 Final report compiling results of the waterbird June 08 and fish habitat study in the Gwydir Wetlands

10 Final report on the Gwydir waterbird and fish habitat study

1.2 The Gwydir Wetlands

1.2.1 Site description

The Gwydir Wetlands are located 60 kilometres west of Moree, in northern NSW (Figure 1). Historically, this area contained one of the most significant semi-permanent wetlands in north-western New South Wales (Keyte 1994) covering an area of 102,120 hectares (Environment Australia 2001). In the lower catchment, the Gwydir River divides into tributary streams, which include the Mehi River, Carole Creek and the Gingham Watercourse and Lower Gwydir River (Figure 1). The core area of semi- permanent wetlands consists of the Gingham Watercourse to the north and the Lower Gwydir River Watercourse (originally known as Big Leather) to the south. These semi- permanent wetlands contain large stands of water couch (Paspalum distichum) and marsh club-rush (Bolboschoenus fluviatilis). This area is thought to be a terminal wetland except during major floods when water reaches the Barwon River (Figure 1). The system is characterised by extremely low slopes (less than 0.05 per cent) (Powell 2005) and contains a mix of semi-permanent wetlands, low-lying floodplain and higher level woodland. In 1999, parts of the Gwydir Wetlands were nominated by four private landowners as wetlands of international importance under the Ramsar Convention. The private Ramsar site covers 823 hectares in total but is comprised of four sub-sites: Big Leather (Old Dromana), Goddard’s Lease, Crinolyn and Windella (Figure 2). Grazing is still permitted on the Ramsar sites under wise use guidelines (DEC 2006). The Old Dromana property was purchased in 2010 by the Australian and NSW Governments through the Australian Government’s Water for the Future – Water Smart Australia program and NSW Rivers Environmental Restoration Program. This property is now reserved under the NSW National Parks and Wildlife Act 1974. The Gwydir Wetlands have supported a grazing industry since the late 1830s but land development for dryland cropping and irrigation has been extensive since the 1970s (McCosker 2001). Copeton Dam was constructed in the upper Gwydir valley in 1976 to provide water for irrigated crops. The dam regulates 55 per cent of inflows (Keyte 1994), with a capacity of 1,364,000 megalitres and an annual average flow of 445,000 megalitres (Morrison 1998). The wetlands also receive unregulated flows from the Horton River (Figure 1). Water management in the Gwydir Valley started in 1902 but major development only started in the 1970s (Powell 2005). The initial plan for the distribution of regulated flows from Copeton Dam was prepared by the Water Resources Commission in 1973, which stated that pastoral activities would continue in the Gwydir Valley and that 60 per cent of the licensed area (56,000 hectares) would be developed for irrigation (McCosker and Duggin 1993). By 1979, the total licensed area had increased to 86,000 hectares (Keyte 1994) but the total area of irrigated land varies considerably among years depending on rainfall and access to water (Hope and Bennett 2003). There are now an estimated 663 irrigation licences in the Gwydir catchment (Hope and Bennett 2003) and at least 300,000 megalitres of on-farm storage capacity to harvest tributary and overland flows (Bennett and McCosker 1994). A major feature of the wetlands is the Gwydir Raft (Figure 2) which is an accumulation of debris, timber and sediment downstream from Moree that has effectively blocked the original river channel from the early 1900s (McCosker 2001). Although the precise date of the raft formation is not known, it is thought to have started in 1888 at Tyreel

Final report on the Gwydir waterbird and fish habitat study 11

(Figure2) and was well-established by the major flood of 1910 (Mahaffey 1985). The Raft’s progression has significantly altered the distribution of floodwaters between the Gingham and Lower Gwydir River watercourses. Prior to 1936, the majority of small floods and freshes entered the Lower Gwydir River Watercourse with only large floods reaching the Gingham Watercourse. With the progression of the head of the Gwydir Raft upstream, this situation has reversed and now the Gingham receives the majority of floodwaters (Keyte 1992).

1.2.2 Flooding history

Large flood events still occur in the Gwydir Wetlands but they are reduced in size and smaller events are less frequent (Kingsford 2000). Under natural conditions, the core wetland area would have flooded approximately 17 per cent of the time over 93 years, but flooding has been reduced to 5 per cent of the time (Kingsford 2000). There has also been a 70 per cent reduction in large floods since regulation and now flooding is only expected in 58 months of a 93-year period (Bennett and Green 1993). As a consequence, wetlands in the Lower Gwydir Watercourse have suffered at least a 75 per cent reduction in area (Keyte 1992). The Mehi River and Carole Creek (Figure 1) have also been channelised to assist in water delivery for the irrigation industry (RIS 1999) and weirs and channels cut for stock and domestic flows have reduced flooding frequency and duration (Kingsford 2000). The Gwydir Wetlands receive an annual rainfall of around 583 millimetres, with rainfall heaviest between November and March (Spencer 2010). At the headwaters this exceeds 750 millimetres (Keyte 1994). Significant floods are considered to exceed 5.18 metres at the Yarraman gauge (Figure 2) (McCosker and Duggin 1993). There have been many reports of floods in the Gwydir system, the earliest being around 1840 (Mahaffey 1985). These floods used to extend across the full width of the lower catchment (WRC 1984). Floods predominantly occur in summer, during January and February, although substantial winter/spring floods have also occurred between 1892 and 1998 (Spencer 2010). Extended wet periods, where several floods occurred over a period of four to six months, generally commenced with winter floods, notably in 1892, 1921, 1950, 1952 (McCosker and Duggin 1993) and in 1998. There have also been extended dry periods. On four occasions these dry periods lasted for at least four years (1895–99, 1912–16, 1935–40 and 1957–63, 1988–93) (McCosker and Duggin 1993). 32 floods were identified in the period May 1977 to January 2005. The longest period between floods was 1,440 days and the largest flood was recorded in July 1998 (Powell 2005). This flood event coincided with a large waterbird breeding event in the following months (October–December 1998) (McCosker 1999a). The Gwydir Wetlands experienced a wet period between 1995 and 2001, which coincided with large waterbird breeding events (McCosker 1996, 1999a, 1999b) and the provision of environmental flows to the Gwydir River under NSW Government reforms (Johnson 2001). The most recent floods were recorded in the summers of 2000–01 and 2004–05 which supported smaller breeding events (see Spencer 2010).

12 Final report on the Gwydir waterbird and fish habitat study

Figure 1. Location of the Gwydir Wetlands, northern NSW

Final report on the Gwydir waterbird and fish habitat study 13

Note that wetland extent and the distribution of farm reservoirs is based on mapping of images taken in 1990. Figure 2. Location of Ramsar sites and major weirs on the Gwydir River system

14 Final report on the Gwydir waterbird and fish habitat study

1.2.3 Historical records of waterbird and fish diversity

At least 75 species of waterbirds have been recorded in the Gwydir Wetlands. On the Old Dromana property (Figure 3) alone, 65 waterbird species (47 breeding) have been recorded (Spencer 2010). Nine species of waterbird recorded in the Gwydir Wetlands are listed as threatened in NSW (NSW Threatened Species Conservation Act 1995, TSC Act) (Appendix 1). Brolgas (Grus rubicundus) are common, and magpie geese (Anseranas semipalmata) and black-necked stork (Ephippiorhynchus asiaticus) have bred along the Gingham Watercourse (McCosker and Duggin 1993; S. Kirkby, pers. comm. 2007). The nationally endangered Australian painted snipe (Rostratula australis) (Environment Protection and Biodiversity Conservation Act 1999, EPBC Act) and the rare blue-billed duck (Oxyura australis) and freckled duck (Stictonetta naevosa) (TSC Act) have also been recorded (Spencer 2010). These duck species are widely distributed in Australia but are most common in the Murray–Darling Basin (Marchant and Higgins 1990). The wetlands have also supported species listed on international migratory bird agreements that Australia has with Japan (JAMBA), China (CAMBA) and the Republic of Korea (ROKAMBA) (Appendix 1). This includes eight species of migratory shorebird (Spencer 2010), most of which are arctic migrants which breed as far north as the Russian Far East and Alaska, and migrate annually to non-breeding grounds in Australia and New Zealand during austral summer (September–April) (Lane 1987). The Gwydir Wetlands are thought to be one of the most important sites in Australia for colonially nesting waterbirds (Kingsford 2000). Colonially nesting waterbirds can congregate in many thousands to breed in small areas of wetland. Records of the Gwydir Wetlands’ significance for colonial waterbirds date back to the 1920s and 1930s (Bailey 1934; Bryant 1934; D’Ombrain 1921; Le Souef 1925; McGill 1944; Morse 1918, 1922a, 1922b; Sullivan 1931). These articles give accounts of vast colonies of little black cormorant (Phalacrocorax sulcirostris), little pied cormorant (Phalacrocorax melanoleucos), glossy ibis (Plegadis falcinellus), Australian white ibis (Threskiornis molucca), straw-necked ibis (Threskiornis spinicollis), royal spoonbill (Platalea regia), yellow-billed spoonbill (Platalea flavipes), intermediate egret (Ardea intermedia), little egret (Ardea garzetta) and great egret (Ardea alba) breeding in swamps and channels of the Gwydir Wetlands. This area was thought to hold the ‘largest heronry in NSW’ with ‘hundreds of thousands of birds breeding there’ (Morse 1922b). In recent years, colonies have been confined to areas surrounding semi-permanent waterholes along the Gingham Watercourse, the most notable being the Gingham, Tillaloo, Boyanga and Baroona waterholes (Figure 3). Major flooding occurred in the Gwydir Wetlands during the summers of 1995–96, 1996–97 and1998–99. This triggered large breeding events along the Gingham Watercourse. The largest breeding event in recent times took place after major flooding (>192,000 hectares) in the spring of 1998. Maximum counts of straw-necked ibis ranged from 150,000–183,000 breeding pairs and large numbers of intermediate egrets (27,000 pairs), rufous night herons (Nycticorax caledonicus) (69,350 pairs), Australian white ibis (38,800 pairs) and glossy ibis (1,650 pairs) were recorded breeding along the Gingham Watercourse (Spencer 2010). Survey data documenting fish diversity and abundance in the Gwydir Wetlands is limited, but at least 12 species of native fish have been recorded in the lower tributaries and floodplain of the Gwydir River (Spencer 2010). Anecdotal accounts of fish

Final report on the Gwydir waterbird and fish habitat study 15

populations in the Gwydir River report severe declines in native fish populations since regulation began, including freshwater catfish (Tandanus tandanus), the threatened Murray cod (Maccullochella peelii peelii) (EPBC Act) and silver perch (Bidyanus bidyanus) (NSW Fisheries Management Act 1994) (Appendix 1) (Copeland et al. 2003). Declines in some native fish populations have been attributed to a combination of impacts including the: • loss of natural flow regimes • construction of barriers to fish migration • removal of logs and debris • competition with introduced fish species, and • cold-water pollution from dam releases (MDBC 2003) (see section 1.2.4). Three introduced species of fish have been recorded in the wetlands: the goldfish (Carassius auratus), Eastern gambusia (Gambusia holbrooki), and European carp (Cyprinus carpio) (Spencer 2010). Carp are thought to have arrived in the Gwydir system from the Barwon in major floods in the 1970s (Copeland et al. 2003). During recent surveys, spangled perch (Leiopotherapon unicolor), carp gudgeons (Hypseleotris spp.) and bony bream (Nematalosa erebi) were the most common native species (Growns and Rodgers 2002; Wilson et al. 2009).

1.2.4 Impacts of river regulation

Altered flow regimes There have been significant changes to the seasonality, frequency and magnitude of flows and also a decline in the size of long-term average flows in the Gwydir system. Changes to flow regimes are thought to be the main threat to wetland health and waterbird and fish populations in regulated systems. Other threatening processes for waterbird and fish populations are exacerbated by the effects of drought and river regulation. The flooding regime of the Gwydir Wetlands has changed significantly since the completion of Copeton Dam in 1976. Post-regulation there has been a 70 per cent reduction in large floods and now flooding is only expected in 58 months of a 93-year period (Bennett and Green 1993). Reduced flooding is not just a consequence of reduced inflows but modification of the channels in the system. Erosion and channelisation have increased the amount of flow required before water will leave the river channels and flow overland (Morrison 1998). The effects of reduced variability have reduced the size and condition of remaining wetland habitats and caused declines in species diversity. Seasonality is an important component of vegetation growth and a trigger for waterbird breeding and spawning in some species of native fish. Prior to river regulation, colonially nesting waterbirds bred frequently (almost annually or every two years) in the Gwydir Wetlands (B. Southeron pers. comm. 2007). Based on records of breeding events and flow data from 1890 to 2004, colonially nesting waterbirds bred on average in seven years of every decade between 1890 and 1980, but post regulation from 1980 to 2007 this declined to breeding attempts in three years in every ten years (Spencer 2010). Some native fish species are more affected by river regulation than others (Gehrke and Harris 2001). The loss of medium flow variability is thought to have favoured alien fish species, such as carp, gambusia and goldfish.

16 Final report on the Gwydir waterbird and fish habitat study

Barriers to fish movements Some native fish species undertake large upstream migrations in order to spawn, e.g. golden perch (Macquaria ambigua) (>1,000 kilometres) and Murray cod (>120 kilometres) (Reynolds 1983; Lintermans 2007). Fish species also move within the river system for feeding and spawning (Lintermans 2007). Other species may depend on floodplains for recruitment (see section 3.2). Levee banks, culverts and channelisation reduce connectivity between the river channels and floodplain wetlands. Some weirs cause direct mortality in larval golden perch and Murray cod (Baumgartner et al. 2006) and seasonal effects on fish assemblages (Baumgartner 2004). Approximately 4,000 barriers to fish passage have been documented in the Murray– Darling Basin (Lintermans 2007). Within the Gwydir system, there are significant barriers to fish passage, in the form of weirs, levees, regulators and boundary fences (Siebentritt 1999; Mallen-Cooper 2000). The Tyreel regulator (Figure 2) is thought to be the largest and most significant barrier to fish passage in the wetlands (Mallen-Cooper 2000). This regulator controls flow into the Lower Gwydir River and Gingham channels. The most common barriers to fish movement in the lower floodplain are medium level (1 metre-high) rock weirs for irrigation and low level (<0.5 metre) rock weirs for road crossings (Mallen-Cooper 2000). Fish species may also be directly removed from the channels with water extracted or diverted by pumps and irrigation channels (Baumgartner et al. 2007).

Declines in water quality Altered flow regimes can cause declines in water quality, including increases in salinity and build-up of agricultural chemicals. Although most adult fish are tolerant of variable salinity, some larval fish and eggs can be highly vulnerable to high levels of salinity (see section 3.2). Channelisation, removal of fringing riparian vegetation, river bank erosion by grazing livestock and high-intensity agriculture can increase sediment loads in river systems which can have deleterious effects on fish during the early life stages (Mallen-Cooper 1993). Cold water releases from dams and storages can also have negative effects on native fish species as many fish rely on water temperature as a cue for spawning. During a study in the Gwydir by Siebentritt (1999), water quality variables were not considered to be a threat to native fish but endosulfan pesticide levels were high and exceeded Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines and levels of acute toxicity for bony bream.

Habitat degradation The reduction in the frequency and magnitude of flooding since the construction of Copeton Dam has caused native vegetation to become stressed in many areas of the Gwydir Wetlands (McCosker 2001). The core areas of semi-permanent wetland vegetation have contracted from about 20,000 hectares to 2,000 hectares (McCosker 1994). Water meadows, lignum (Muehlenbeckia cunninghamii) associations and river red gums (Eucalyptus camaldulensis), which many waterbirds depend on for feeding and breeding habitat, are reliant on flooding. Native pastures that have been adapted to flooding have lost vigour and are being invaded by lippia (Phyla canescens), burrs and thistles (McCosker 2001). Water hyacinth (Eichhornia crassipes) has also established in parts of the Gingham Watercourse, notably the Gingham Waterhole (Figure 3).

Final report on the Gwydir waterbird and fish habitat study 17

The degradation of riparian vegetation and removal of snags and other cover has reduced habitat diversity for waterbird and fish species. The loss of riparian vegetation can decrease nutrient inputs, shade and shelter for fish and increase flow rates and sediment loads. Reduced nutrient loads can also impact on zooplankton populations which are important food items for larval fish. The clearing of native vegetation was listed as a key threatening process in NSW (TSC Act). Significant clearing of remnant native vegetation has occurred in the catchment in recent times, in response to the invasion of lippia (Murphy-Fleming and Moles 2003). This included the clearing of the Windella Ramsar site (Figure 2) and adjacent areas (Murphy-Fleming and Moles 2003) and of over 500 hectares of native vegetation on the Yarrol property in the Gingham Watercourse in April 2007. Prior to clearing, this area supported the most significant remaining nesting sites for colonial waterbirds in the Gwydir Wetlands (Spencer 2010).

Alien species Alien species are defined as species introduced from overseas that have established in the wild (Harris and Gehrke 1997). Eleven alien fish species have been recorded in the Murray–Darling Basin (Lintermans 2007). The European carp is the most widespread large-bodied fish in the basin (Stuart and Jones 2006) and is thought to have negative effects on native fish and freshwater systems. The indirect effects of carp include reductions in aquatic macrophytes, increases in turbidity and channel erosion (Fletcher et al. 1985; King et al. 1997; Robertson et al. 1997). Carp are thought to have contributed to observed declines in native fish by exacerbating the effects of altered flow regimes. Gambusia also have significant effects on native fish, as they are an aggressive species and compete with native fish for food, chasing and nipping much larger fish and also consume the larvae and eggs of other fish species (Lintermans 2007). Alien fish species have also introduced pathogens and diseases into the Murray–Darling Basin. For example, carp and goldfish carry the parasitic anchor worm (Lernaea sp.), which has been observed on several native fish species including the Murray cod, golden perch, silver perch, Macquarie perch (Macquaria australasica) and freshwater catfish (Lintermans 2007).

18 Final report on the Gwydir waterbird and fish habitat study

2. Field surveys (2007–08)

2.1 Methods

2.1.1 Waterbird surveys

Waterbird surveys were carried out in the Gwydir Wetlands in October 2007 and April 2008 using a combination of aerial surveys and replicate ground counts. (See summary reports for detailed descriptions of survey methods: Spencer 2007; Spencer 2008).

Aerial surveys A helicopter was used to survey waterbirds in the Gwydir Wetlands in early October 2007 (8–9 October 2007). This helicopter survey was designed to provide a detailed assessment of wetland condition and to identify any waterbird breeding in the Gwydir Wetlands. Total numbers of waterbirds were recorded on the four channels in the Gwydir Wetlands: the Lower Gwydir River channel, Gingham Watercourse, Mehi River and Carole Creek (Figure 3). The first survey was flown north-west along the Gingham Watercourse and then east along the Lower Gwydir River watercourse (8 October) and the second survey (9 October) followed the Mehi River west to Moomin Creek and returned east along Carole Creek (Figure 3). Sixty-three sites were surveyed in total, which included 14 floodplain sites, 26 in-channel sites, eight floodplain waterholes and 15 artificial sites (14 farm storages and the Moree sewage treatment works) (Figure 3). Farm storages were counted on an ad hoc basis. The survey methodology followed Braithwaite et al. (1986) and Porter et al. (2006), whereby the survey team consisted of a pilot, a front right observer and a back left observer and the survey was flown at a height of approximately 45 metres (150 feet) and an air speed of 200 kilometres per hour (110 knots). Total counts of each waterbird species at each wetland site were recorded onto a mini-cassette recorder, which were transcribed later. Due to difficulties in identification, in most cases, egret species were grouped and tern species were grouped. Bird distribution ranged from aggregated to highly dispersed, therefore, count type was determined during the point of survey. Estimates of waterbird numbers on discrete sites, such as floodplain waterholes and farm storages, were treated as total counts. Proportion counts were used for sections of river channels and large floodplain areas. An estimate of the total coverage (%) for each site was made by each observer for proportion counts. The extent of wetland area was also estimated for each site, based on the size of the wetted area as a proportion of the site. The boundary of each site varied from dam walls for farm storages to maximum potential floodplain area for in-channel sites. Start and finish points were recorded for each site using the aircraft’s on-board Global Positioning System. Aerial surveys were carried out in a high-winged aircraft (DECC Cessna 206) in both the 2007 (29–30 October) and 2008 survey periods (28–29 April). The October survey was carried out as an extension of the eastern Australia wetland bird surveys coordinated by Professor Richard Kingsford and Dr John Porter, UNSW. This survey technique is most appropriate for monitoring long-term trends in waterbird numbers in the Gwydir Wetlands, as waterbirds are highly mobile over large spatial scales. During the light aircraft aerial surveys, 12 floodplain sites, 18 in-channel sites, five to eight

Final report on the Gwydir waterbird and fish habitat study 19

floodplain waterholes and five to ten farm storages were surveyed [October 2007 (n = 40); April 2008 (n = 48)]. The total number of floodplain waterholes and farm storages surveyed varied according to water availability in the floodplain. Farm storages were counted on an ad hoc basis (see Spencer 2007 and Spencer 2008). The same methodology was used to survey sites as in the helicopter surveys (see above).

Replicate ground counts A sub-sample of sites was visited during ground surveys of waterbird habitats. These surveys were used to ground-truth the aerial surveys. Ground surveys for waterbirds were carried out at 24 sites along the Gingham Watercourse, Lower Gwydir River, Carole Creek and Mehi River in October 2007 (2–12 October) and April 2008 (18 April– 1 May) (Figure 4). Sites were categorised into four wetland types: channel (n = 7), floodplain waterholes (n = 6), floodplain (n = 7) and farm storages (n = 4). Replicate counts were made on three separate survey days for sites that held water. Large floodplain areas on Old Dromana (Lower Gwydir River) and Bunnor (Gingham) were assessed by sub-sampling an area of approximately 500 metres x 200 metres at each site. Total counts of each waterbird species, behaviour, microhabitat, evidence of breeding activity and vegetation descriptions were recorded during the surveys.

20 Final report on the Gwydir waterbird and fish habitat study

Figure 3. Site locations for aerial surveys of waterbirds in the Gwydir Wetlands (October 2007, April 2008)

Final report on the Gwydir waterbird and fish habitat study 21

Figure 4. Sites surveyed during ground surveys for waterbirds in the Gwydir Wetlands (October 2007, April 2008)

22 Final report on the Gwydir waterbird and fish habitat study

2.1.2 Fish surveys

Fish surveys were carried out in the Gwydir Wetlands in spring 2007 (13–19 November) and summer 2008 (12–19 March) (see Spencer 2007, Spencer 2008 for full methods). Eleven in-channel sites were sampled during the two survey periods (Figure 5). Two of these sites were downstream of major weirs on the Mehi, Carole, Gingham and Lower Gwydir river channels, two sites were upstream on the Gwydir River and a single site was located upstream on the Mehi River (Figure 5). Each site was approximately 300 metres in length. Water quality variables, conductivity (micro Siemens per centimetre), pH and temperature (degrees Celsius), and flow rate (metres/second) were recorded at each site during both survey periods. Three methods were used to sample fish species in the in-channel sites: seine netting, bait traps and fyke nets. A seine net (2 metres x 20 metres; 2 millimetre mesh) was used to sample three sections (about 20 metres in length) at each site. Six bait traps (25 centimetres x 10 centimetres; 5 millimetre mesh) were set overnight (for between 15–19 hours) at each site. Traps were baited and positioned near large logs at each site. Two large (2 metre x 10 metre wings; 12 millimetre mesh) and two small (2 metre x 2 metre wings; 2 millimetre mesh) fyke nets were left at each site overnight (15–19 hours). One large fyke net and one small fyke net was positioned at each end of the sampling area with one pair facing upstream and the other pair facing downstream. Wing width and depth, and channel and bank widths (metres) were recorded at the location of each pair of fyke nets. Total numbers of freshwater fish, prawns, yabbies and turtles caught in the nets were recorded. Fish species were identified and measured to the nearest millimetre (standard length). Australian smelt (Retropinna semoni) were not measured as this species was adversely affected by handling. Three species of carp gudgeons were identified (see Appendix 1), but due to difficulties in identification in the field, the Midgley’s carp gudgeon (Hypseleotris sp. 1) and Lake’s carp gudgeon (Hypseleotris sp. 2) were grouped as carp gudgeons in the analysis. The Western carp gudgeon (Hypseleotris klungzingeri) was identified in the field and analysed separately. Shell length (centimetres) was recorded for each turtle caught. Specimens of bony bream and Australian smelt collected during surveys in November 2007 were retained for an otolith increment study (Heagney et al. 2009). Bony bream (180 specimens) were measured (standard length) and weighed (grams) in the laboratory. Each fish was dissected to extract otoliths (ear bones) and to determine the sex and score the gonad condition of each individual. The gonads were scored as following: no gonad (0); gonad present but small (1); large gonad but uniform in colour and size (2); and large swollen gonad, very dark and granular in females and tinged red in males (3) (Puckridge and Walker 1990). During survey work in March 2008, additional surveys were carried out at five floodplain waterholes: Baroona, Tillaloo, Talmoi, Old Dromana and Whittakers Lagoon (15–19 March) (Figure 5). Talmoi, Tillaloo and Baroona waterholes are located to the north of the Gingham Watercourse. These waterholes lie within an old river bed, which fills primarily during moderate floods from a channel originating in the Gingham Watercourse. The precise depths of these three waterholes is not known but the Talmoi and Baroona waterhole are believed to have maximum depths of three to four metres (Siebentritt 1999), while the Tillaloo waterhole is very shallow (<0.5 metre). Whittakers Lagoon is located to the north of the Mehi River and is a small depression that fills from local rainfall and run-off. The Old Dromana waterhole is a flooded area on

Final report on the Gwydir waterbird and fish habitat study 23

the north-western edge of the Ramsar site that fills from a stock and domestic bore drain that borders the Ramsar site. Sampling of the floodplain waterholes was coordinated by the WRP trophic dynamics study (see section 1.1.1). Four small fyke nets were set overnight at each waterhole (except at Old Dromana where three nets were used) and retrieved the following day. Fish species were identified and size measurements were pooled across fyke nets. Three replicates of water quality parameters were taken at the five waterholes (see Spencer 2008).

24 Final report on the Gwydir waterbird and fish habitat study

Figure 5. Sampling locations for fish surveys in the Gwydir Wetlands (November 2007; March 2008)

Final report on the Gwydir waterbird and fish habitat study 25

2.1.3 Site conditions

In general, the wider floodplain was extremely dry during field surveys in October 2007, following an extended period of low rainfall and low flows in winter months in 2007 (Figure 6). During surveys in October–November 2007, available water was confined to the river channels and farm storages. Fish and waterbird surveys carried out in March and April 2008 followed higher flows in the system from late November 2007–February 2008 (Figure 6). These surveys followed an environmental flow release into the system in mid-December 2007 and flows from heavy rainfall in the upper catchment in January and February 2008. The Gwydir Wetlands also received heavy local rainfall in late December 2007 and mid-February 2008 (Figure 6).

Daily Rainfall Mean Discharge 80 12000

70 10000

60 8000

50 6000 40 4000

Total rainfallTotal (mm) 30

2000 dischargeMean (ML/day) 20

10 0

0 -2000 Jun-07 Aug-07 Oct-07 Dec-07 Feb-08 Apr-08

Rainfall data recorded at Moree Post Office gauge (Bureau of Meteorology 2008) and flow data recorded for the Gwydir River at Yarraman Bridge, Moree (gauge no. 418004) (NOW Daily River Reports 2008).

Figure 6. Total daily rainfall and mean daily discharge for the Gwydir River from June 2007–May 2008

26 Final report on the Gwydir waterbird and fish habitat study

2.2 Results

2.2.1 Waterbirds

(i) Waterbird distribution In total, 45 waterbird species were recorded during field surveys in the Gwydir in 2007– 08 (Appendix 1). More waterbirds were detected during aerial surveys in April 2008 (4,447 birds, 23 species) than in October 2007 (1,007 birds, 19 species) (Table 2), however, the area inundated was extremely low during surveys in October 2007. In surveys in October 2007, waterbird species were confined to water available in the main channels and on artificial sites (farm storages and Moree sewage works) (Figure 7). Further floodplain habitats were inundated and became available in April 2008 at flooded waterholes on the Gingham floodplain (Baroona, Tillaloo and Talmoi), which provided habitat for several duck species (Table 2; Figure 7). There was also an increase in the number of waterbirds using floodplain sites on the Lower Gwydir River and Gingham Watercourse during surveys in April 2008 (752 birds) compared to surveys in October 2007 (134 birds) (Table 2). Artificial sites attracted species from the Anatidae (ducks and swans) and Phalacrocoracidae (cormorants) families, which favour deep, permanent waterbodies. Other waterbird species, such as Australian white ibis, white-faced herons (Ardea novaehollandiae) and egrets were more common on the natural floodplain areas (Table 2). Overall, 22 species of waterbird were recorded on the floodplain sites (n = 12) and artificial sites, 12 species on floodplain waterholes (n = 8) and 14 species at the in-channel sites (n = 18) (Table 2). During aerial surveys conducted in October 2007, Australian pelicans (Pelecanus conspicillatus) (268 birds), pied cormorants (Phalacrocorax varius) (236 birds) and Australian wood duck (Chenonetta jubata) (136 birds) were the most abundant species but these species were largely restricted to artificial sites (Table 2). During aerial surveys in April 2008, the most abundant species were from the Anatidae family, in particular plumed whistling duck (Dendrocygna eytoni) (2,462 birds), Australian wood duck (658) and grey teal (Anas gracilis) (593). These species were recorded in greatest numbers at the Talmoi Waterhole (Figure 3). Relatively few colonial waterbirds were recorded during aerial surveys in 2007 and 2008. Total counts of straw-necked ibis (0– 6), Australian white ibis (12–104) and egret species (37–46) were low during both survey periods (Table 2). In total, 42 species were recorded during ground surveys in October 2007 and 37 during surveys in April 2008. Results of the ground counts were consistent with the aerial surveys. The largest concentrations of waterbirds were around large waterbodies, such as the Talmoi and Baroona waterholes, on the Gingham Watercourse, and farm storages near Carole Creek (Table 3). In-channel (n = 7) and farm storage (n = 6) survey sites supported the greatest number of waterbirds during ground surveys in October 2007, while the floodplain waterholes (n = 6) supported the most waterbirds in April 2008 (Table 3). All seven floodplain survey sites were extremely dry in October 2007, including the three Ramsar sites surveyed (see Spencer 2007). The condition of the floodplain sites had improved by April 2008, following inundation from December 2007–February 2008 but many of the sites, including the Ramsar sites, had dried back since this wetter period.

Final report on the Gwydir waterbird and fish habitat study 27

Species composition was similar in both survey periods. The most abundant waterbird species recorded in October 2007 ground surveys were grey teal (maximum count 138 birds), pacific black duck (Anas superciliosa) (45 birds), Australian wood duck (48 birds) and whiskered terns (Chlidonias hybrida) (51 birds) (Table 4). Plumed whistling ducks were the most abundant species in the April 2008 ground surveys (maximum count of 1,946 birds at the Talmoi Waterhole). The next most abundant species were Australian wood ducks (302 birds), Australasian grebes (Tachybaptus novaehollandiae) (121 birds) and grey teals (76 birds) (Table 4). Six species listed on international migratory bird agreements and two threatened species listed were recorded during the field surveys in 2007–08. Two species of migratory shorebird, the common greenshank (Tringa nebularia) and Latham’s snipe (Gallinago hardwickii) which spend their non-breeding season in Australia (September– April) were recorded in the wetlands during ground surveys in early October 2007. Further, 65 brolgas were observed south of the Mehi River during aerial surveys in October 2007 and a black-necked stork was observed near the Boyanga waterhole, on the Gingham, during ground surveys in October 2007 and nesting on the Bunnor property in April 2008. Both species are listed as vulnerable in NSW (TSC Act). Most waterbird species observed during the ground counts were engaged in roosting and loafing (inactive) behaviour. Foraging activity comprised 21.4 per cent, and preening 10.2 per cent, of waterbird behaviour during surveys in April 2008 (see Spencer 2008). Waterbird species used a variety of microhabitats at the survey sites. Open water (52.1 per cent) and open water/wet mud (21.0 per cent) was the most important microhabitat for foraging birds in surveys in April 2008. Bare earth and dead trees provided important roosting habitat for some species, such as herons, darters (Anhinga melanogaster) and ibis.

28 Final report on the Gwydir waterbird and fish habitat study

October 2007

April 2008

Figure 7. Total numbers of waterbirds recorded in the Gwydir system during light aircraft aerial surveys in October 2007 (n = 40) and April 2008 (n = 48) (n = number of survey sites)

Final report on the Gwydir waterbird and fish habitat study 29

Table 2. Total counts of each waterbird species recorded in the Gwydir Wetlands during light aircraft aerial surveys in October 2007 (n = 40) and April 2008 (n = 48)

Channel Waterholes Floodplain Artificial* Total Common name 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 (n = 18) (n = 18) (n = 5) (n = 8) (n = 12) (n = 12) (n = 5) (n = 10) (n = 40) (n = 48) Australian pelican 72 0 3 0 3 0 190 0 268 0 Australian white ibis 10 20 0 0 2 84 0 0 12 104 Australian wood duck 71 75 0 158 40 218 25 207 136 658 Black swan 2 0 0 2 0 10 2 5 4 17 Black-winged stilt 0 0 0 0 10 0 3 0 13 0 Brolga 0 0 0 0 12 4 0 0 12 4 Darter 5 6 0 5 0 2 10 15 15 28 Egret 7 1 1 2 25 34 4 9 37 46 Eurasian coot 0 0 0 0 0 0 0 46 0 46 Glossy ibis 0 0 0 0 20 0 0 0 20 0 Great cormorant 3 0 0 1 3 0 1 1 7 2 Great egret 0 0 0 0 1 1 0 0 1 1 Great-crested grebe 0 0 0 0 0 0 0 1 0 1 Grey teal 5 16 0 76 6 237 29 264 40 593 Hardhead 0 0 0 0 0 0 1 0 1 0 Little black cormorant 5 7 0 0 0 15 7 4 12 26 Little pied cormorant 0 0 0 0 0 1 0 1 0 2 Masked lapwing 0 0 0 0 1 3 0 0 1 3 Pacific black duck 0 4 0 12 0 48 0 73 0 137 Pied cormorant 1 1 0 10 0 11 235 3 236 25

30 Final report on the Gwydir waterbird and fish habitat study

Channel Waterholes Floodplain Artificial* Total Common name 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 Plumed whistling duck 0 0 0 625 0 10 0 2007 0 2642 Royal spoonbill 0 0 0 0 0 0 0 3 0 3 Straw-necked ibis 0 2 0 1 0 3 0 0 0 6 Tern spp. 0 0 0 0 0 0 0 10 0 10 Silver gull 0 0 0 0 0 0 13 0 13 0 White-faced heron 1 0 0 0 2 44 3 6 6 50 White-necked heron 0 4 0 1 3 26 0 7 3 38 Yellow-billed spoonbill 0 0 0 0 0 1 05 4 0 5 Total 271 136 14 893 134 752 588 2,666 1,007 4,447

*Artificial sites include farm storages and Moree sewage works (n = number of survey sites).

Final report on the Gwydir waterbird and fish habitat study 31

Table 3. Mean (± standard error) total counts of waterbirds recorded during ground surveys of the Gwydir Wetlands in October 2007 (n = 49) and April 2008 (n = 63)

River Site name Site October 2007 April 2008 system type* Mean Total Mean Total (+/-s.e.) species (+/- s.e.) species Carole Beela Dam North FS 44.7 (8.4) 16 57.3 (31.2) 10 Carole Beela Dam South FS 178.7 (32.2) 21 30.7 (2.0) 16 Carole Laurella Dam North FS 109.7 (9.4) 22 127.0 (13.0) 17 Carole Laurella Dam South FS 15.0 (2.5) 9 5.3 (2.3) 6 Carole Marshalls Pond FP - 0 4.7 (2.3) 7 Carole Sappa CH - 2 1.7 (1.7) 4 Carole Sappa Remnant FP - 0 - 0 Gingham Baroona Waterhole WH - 0 92.0 (11.8) 15 Gingham Boyanga CH 64.0 (22.4) 20 39.7 (3.9) 16 Gingham Bunnor FP - 0 38.0 (11.9) 13 Gingham Crinolyn (Ramsar) FP - 0 26.3 (2.2) 8 Gingham Goddard’s Lease (Ramsar) FP - 0 - 0 Gingham Gwydir Raft/Tyreel Weir CH 4.3 (2.3) 5 0 (0) 0 Gingham Jackson FP 58^ 9 38.3 (10.0) 13 Gingham Talmoi Waterhole WH - 0 1,963.7 (332.9) 16 Gingham Tillaloo Waterhole WH - 0 12.7 (2.8) 9 Lower Gwydir Old Dromana Floodplain (Ramsar) FP - 0 - 0 Lower Gwydir Old Dromana Overspill (Ramsar) WH 25.3 (3.8) 11 15.7 (3.2) 8 Mehi Combadello Weir CH 5.3 (1.8) 7 1.0 (0.6) 2 Mehi Derra CH 5.3 (2.8) 3 0.3 (0.3) 1 Mehi Derra Waterhole WH - 0 22.5 (9.5) 6 Mehi Mary Brand Park Lagoon CH 103.7 (14.7) 15 68.0 (11.5) 15 Mehi Telleraga CH 0 (0) 0 0 (0) - Mehi Whittakers Lagoon WH 3.3 (2.8) 5 39.3 (11.1) 12

*Site type: WH = waterhole, FP = floodplain, CH = channel, FS = farm storage. Dry sites were only surveyed once. See Methods in Spencer (2007; 2008) for detailed methods and Figure 4 and Appendix 2 for site locations. ^ Jackson was only surveyed once in ground surveys in October 2007 (n = total surveys).

32 Final report on the Gwydir waterbird and fish habitat study

Table 4. Maximum counts of waterbird species recorded during ground counts in the Gwydir Wetlands in October 2007 (n = 49) and April 2008 (n = 63)

Species October 2007 April 2008 Australasian grebe 23 121^ Australian pelican 4 0 Australasian shoveler 0 5 Australian white ibis 25 29 Australian wood duck 48^ 302 Black swan 5^ 2 Black-fronted dotterel 2 9 Black-necked stork 0 2^ Black-tailed native hen 10 1 Black-winged stilt 25 3 Brolga 2 3 Caspian tern 1 1 Common greenshank 1 0 Cattle egret 0 1 Darter 5 7 Dusky moorhen 5 1 Eurasian coot 13 7 Glossy ibis 6 0 Great cormorant 1 1 Great egret 1 1 Great-crested grebe 2 2 Grey teal 138 76^ Gull-billed tern 21 2 Hardhead 10 8 Hoary-headed grebe 32 8 Intermediate egret 3 11 Latham’s snipe 1 0 Little black cormorant 7 9 Little pied cormorant 2 14 Masked lapwing 2 4 Musk duck 3 0 Rufous night heron 1 0 Pacific black duck 45 22 Pied cormorant 11 3

Final report on the Gwydir waterbird and fish habitat study 33

Species October 2007 April 2008 Pink-eared duck 10 2 Plumed whistling duck 0 1,946^ Purple swamphen 10 8 Red-kneed dotterel 4^ 0 Royal spoonbill 2 28 Silver gull 1 0 Straw-necked ibis 0 16 Whiskered tern 51 13 White-faced heron 3 7 White-necked heron 2 5 Yellow-billed spoonbill 5 1 Total species 40 37

^ Breeding recorded during surveys (n = number of surveys)

(ii) Waterbird breeding There was limited evidence of waterbird breeding in the Gwydir Wetlands during field surveys in 2007–08. Only seven species were recorded breeding (Table 4). Juvenile red-kneed dotterels (Erythrogonys cinctus), black swans (Cygnus atratus) and Australian wood ducks were observed in ground surveys in October 2007. In April 2008 ground surveys, Australasian grebes were observed breeding at the Baroona, Tillaloo and Talmoi waterholes, on the Gingham Watercourse and at the Whittakers and Derra waterholes, on the Mehi River (Figure 4). The proportion of young grebes ranged from 20–60 per cent of flock counts at these sites. The highest counts of young grebes were recorded at Talmoi Waterhole (47 chicks), followed by Baroona Waterhole (9 chicks), Whittakers Lagoon (4 chicks), Derra Waterhole (3 chicks) and Tillaloo Waterhole (1 chick). Single pairs of grey teal and plumed whistling duck were also recorded with young in April 2008. In ground surveys in April 2008, black-necked storks were observed nesting in a large belah tree (Casuarina cristata) on the Bunnor property outside of the floodplain survey area. During subsequent site visits in April, both adults and three young chicks were observed at the nest. Unfortunately, high winds in the following month damaged the nest, causing this nesting attempt to fail (D. Albertson (DECCW) pers. comm. June 2008).

34 Final report on the Gwydir waterbird and fish habitat study

2.2.2 Fish

(i) Fish diversity Eleven native fish species and three alien species were recorded during field surveys conducted in the Gwydir in November 2007 and March 2008 (Appendix 1). Native fish species outnumbered alien species at all in-channel survey sites (Table 5). In November 2007, the most common fish were Australian smelt (1,485 fish) and bony bream (563 fish) (Table 5). Australian smelt were most common at sites along Carole Creek, while bony bream were recorded in greatest abundance at Boyanga (GH2), Gingham Watercourse and Allambie (LG2), Lower Gwydir River in the 2007 surveys. In the March 2008 surveys, the most common native fish species were bony bream (1,224 fish) and Murray–Darling rainbowfish (Melanotaenia fluviatilis) (699 fish) (Table 5). Highest species diversity was recorded at Redmill (GW1) (12 species), upstream on the Gwydir River in the November surveys, and at Jackson (GH1), on the Gingham (10 species) during the March surveys. The lowest number of species was recorded at Telleraga (MH2) (3 species) in November and Chinook (MH3), on the Mehi River in March (Table 5). Numbers of spangled perch were low and restricted to sites along the Gingham Watercourse during November 2007 surveys. During the March 2008 surveys, this species had expanded into sites along the Lower Gwydir River, Carole Creek and floodplain waterholes, in particular Tillaloo, Baroona and Talmoi on the Gingham floodplain. The largest fish specimens were generally caught at sites on the Mehi River, and included mature freshwater catfish, Murray cod and golden perch. Three alien fish species were recorded during surveys; carp, gambusia and goldfish. Overall, the total number of alien fish was low during both November 2007 (6 per cent of catch) and March 2008 (7 per cent of catch) surveys (Table 5). Carp were the most abundant alien fish species and were most common at sites on the Gingham Watercourse. In total, 55 carp (2.0–46.4 centimetres) were caught at Jackson (GH1) in November 2007 surveys and 80 carp (4.7–35.2 centimetres) in March 2008 surveys (Table 5; Table 6). Numbers of alien fish were lowest at sites along the Mehi River (Table 5). Freshwater prawns (Macrobrachium spp.) were highly abundant at the sampling sites during both survey periods. Yabbies (Cherax destructor) were also widespread and had increased in numbers in March 2008 surveys (Table 5). Eastern snake-necked turtles (Chelodina longicollis) were commonly caught in the large fyke nets and were most abundant at Boyanga waterhole in November 2007 surveys. A second species of turtle, a large broad-shelled turtle (Chelodina expansa) was caught at Jackson (GH1) in March 2008 (Table 5).

Final report on the Gwydir waterbird and fish habitat study 35

Table 5. Total numbers of each fish species, turtles and invertebrates caught at each sampling site in the Gwydir Wetlands in November 2007 and March 2008 (n = 11)

Downstream Upstream CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 Total Common name 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 Australian smelt 522 68 404 144 8 9 0 0 0 0 26 0 12 0 41 0 194 78 141 145 137 139 1,485 583 Bony bream 1 197 6 59 11 99 81 234 15 283 343 190 12 13 18 6 22 6 37 71 17 66 563 1,224 Carp gudgeons* 0 0 2 7 1 0 0 0 2 0 3 0 0 0 0 6 4 0 62 19 50 9 124 41 Eastern gambusia^ 6 17 1 2 0 4 0 5 5 11 0 0 0 0 0 5 0 0 1 13 0 27 13 84 European carp^ 5 3 4 0 55 80 6 16 2 3 2 13 8 2 0 3 0 0 22 0 0 0 104 120 Freshwater catfish 1 0 2 0 0 1 0 0 0 1 0 1 2 0 0 0 2 0 9 0 1 0 17 3 Golden perch 0 0 0 2 1 3 0 0 0 0 0 0 13 2 0 1 1 0 1 0 2 0 18 8 Goldfish^ 5 1 1 0 27 26 16 22 3 0 11 2 1 0 0 0 0 0 6 0 3 1 73 52 Murray cod 0 0 0 0 0 1 0 0 0 0 0 0 6 4 0 0 0 0 1 0 0 0 7 5 Rainbowfish 59 158 1 36 0 0 0 0 31 61 1 0 0 0 0 0 2 7 10 41 64 396 168 699 Spangled perch 0 27 0 1 4 54 52 31 0 13 0 4 0 0 0 0 0 0 0 0 0 0 56 130 Hardyhead 4 44 0 2 0 0 0 5 0 9 10 0 0 0 0 0 0 0 11 3 83 42 108 105 Western carp 6 8 36 61 15 25 4 0 0 0 5 0 35 1 68 153 9 5 33 175 121 163 332 591 gudgeon Total species 9 9 9 9 8 10 5 6 6 7 8 5 8 5 3 6 7 4 12 7 9 8 84 14 Total fish 618 523 466 314 130 302 164 313 64 381 409 210 97 22 130 174 241 96 346 467 487 843 3,152 3,645 Total alien fish 16 21 6 2 82 110 22 43 10 14 13 15 9 2 0 8 0 0 29 13 3 28 190 256 Other Broad-shelled turtle 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Snake-necked turtle 0 0 3 1 3 0 11 2 0 0 1 0 2 0 2 1 1 0 0 0 1 0 24 4 Prawn/shrimps 1,098 1431 909 6,318 1,309 949 334 650 445 1,459 344 922 1,041 511 3,679 728 1,780 466 2,073 1,946 2,188 1,630 15,200 17,010 Yabby 7 45 5 30 2 4 8 81 41 156 53 62 0 2 1 5 0 0 3 2 0 1 120 388

* Carp gudgeon species were grouped due to difficulties in identifying specimens in the field. This group included the Midgley’s carp gudgeon (Hypseleotris sp. 1) and Lake’s carp gudgeon (Hypseleotris sp. 2). The Western carp gudgeon (Hypseleotris klungzingeri) was identified in the field and analysed separately. ^ Alien species (see Appendix 1 for species names). See Figure 5 for site locations. Site codes: Downstream: Carole Creek CC1 = Sappa, CC2 = Laurella; Gingham GH1 = Jackson, GH2 = Boyanga; Lower Gwydir River LG1 = Wearmatong, LG2 = Allambie; Mehi River MH1 = Derra, MH2 = Telleraga. Upstream sites: Mehi River MH3 = Chinook; Gwydir River GW 1 = Redmill, GW 2 = Beela.

36 Final report on the Gwydir waterbird and fish habitat study

Table 6. Mean (± standard error) standard length (centimetres) of fish species collected in the Gwydir Wetlands (2007–08) (a) November 2007

Common name CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 All sites Bony bream 12.7 (-) 19.9 (3.3) 14.5 (2.4) 5.4 (0.4) 4.2 (0.6) 7.8 (0.3) 19.3 (1.1) 16.2 (1.2) 4.6 (0.9) 5.6 (1.3) 11.8 (1.8) 8.1 (0.3) European carp^ 3.4 (0.3) 3.4 (0.3) 22.1 (1.8) 22.9 (3.4) 4.9 (0.3) - 36.6 (1.8) - - 3.1 (0.2) - 17.2 (1.4) Freshwater catfish 21.0 (-) 29.8 (1.8) - - - - 35.6 (6.8) - 0.9 (0.7) 6.3 (4.5) 33.0 (-) 14.3 (3.9) Eastern gambusia^ 2.1 (0.1) 1.9 (-) - - 2.0 (0.2) - - - - 2.9 (-) - 2.1 (0.1) Golden perch - - 3.2 (-) - - - 28.8 (0.9) - 24.2 (-) 20.0 (-) 14.3 (1.0) 25.0 (1.9) Goldfish^ 3.2 (0.3) 10.2 (-) 2.7 (0.3) 6.5 (1.0) 4.6 (0.4) 8.9 (0.3) 16.7 (-) - - 3.2 (0.4) 6.5 (3.0) 5.1 (0.4) Murray cod ------35.6 (2.1) - - 2.7 (-) - 30.9 (5.0) Rainbowfish 1.5 (0.0) 1.6 (-) - - 3.0 (0.2) 3.2 (-) - - 3.8 (0.0) 1.8 (0.2) 1.8 (0.1) 2.0 (0.1) Spangled perch - - 7.2 (1.4) 9.4 (0.3) ------9.2 (0.3) Unspecked hardyhead 4.0 (0.3) ------4.5 (0.1) 4.0 (0.1) 4.1 (0.1)

(b) March 2008

Common name CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 All sites Bony bream 5.7 (0.1) 6.9 (0.3) 10.3 (0.3) 9.2 (0.2) 6.1 (0.1) 8.4 (0.3) 17.1 (2.1) 9.8 (3.2) 3.6 (0.1) 8.7 (0.9) 8.7 (0.5) 7.8 (0.1) European carp^ 11.5 (1.2) - 13.2 (0.8) 8.4 (1.5) 14.9 (4.2) 8.9 (0.7) 37.3 (1.7) 18.0 (13.8) - - - 12.6 (0.7) Freshwater catfish - - 8.5 (-) - 12.7 (-) 10.0 (-) - - - - - 10.4 (1.2) Eastern gambusia^ 1.7 (0.1) 2.5 (0.1) 2.3 (0.1) 1.8 (0.1) 3.0 (0.2) - - 2.0 (0.2) - 1.9 (0.1) 2.4 (0.1) 2.2 (0.1) Golden perch - 14.8 (8.2) 40.2 (2.2) - - - 29.8 (0.3) 27.5 (-) - - - 29.7 (4.1) Goldfish^ 7.8 (0.0) - 6.7 (0.4) 5.3 (0.3) - 8.7 (2.5) - - - - 8.4 (-) 6.2 (0.3) Murray cod - - 27.0 (-) - - - 39.8 (4.9) - - - - 37.2 (4.6) Rainbowfish 4.1 (0.0) 4.0 (0.3) - - 5.3 (0.1) - - - 4.3 (0.2) 3.2 (0.1) 3.4 (0.0) 3.7 (0.0) Spangled perch 3.9 (0.2) 3.5 (-) 6.4 (0.4) 8.2 (0.4) 7.3 (0.4) 11.9 (2.4) - - - - - 6.6 (0.3) Unspecked hardyhead 4.0 (0.1) 2.9 (1.3) - 3.9 (0.2) 4.2 (0.2) - - - - 2.3 (0.2) 3.7 (0.1) 3.8 (0.1) Western carp gudgeon* 2.4 (0.1) 2.4 (0.1) 1.8 (0.1) - - - 2.1 (-) 2.6 (0.0) 2.6 (0.1) 2.4 (0.0) 2.3 (0.0) (0.0)

^ Alien species * Note that Western carp gudgeons were only measured during the second sampling period. Site codes: Downstream: Carole Creek CC1 = Sappa, CC2 = Laurella; Gingham GH1 = Jackson, GH2 = Boyanga; Lower Gwydir River LG1 = Wearmatong, LG2 = Allambie; Mehi River MH1 = Derra, MH2 = Telleraga. Upstream sites: Mehi River MH3 = Chinook; Gwydir River GW 1 = Redmill, GW 2 = Beela (see Figure 5).

Final report on the Gwydir waterbird and fish habitat study 37

Table 7. Characteristics of fish survey sites in the Gwydir Wetlands (November 2007, March 2008)

Site dimensions * Water quality ^ Site type River system Site Channel Bank width Depth (m) Conductivity pH Temp (ºC) Flow rate Site description width (m) (m) (µS/cm) (m/sec) Downstream Carole creek CC1 6.7–16.7 10.5–16.7 0.4–0.8 281.3–433.0 6.9–8.0 26.0–26.8 0.13–0.31 Riffles, few logs, clay–gravel substrate

CC2 8.8–13.8 15.2–19.5 0.5–1.7 371.0–429.7 6.7–7.4 23.0–25.9 <0.03 Logs across channel, high canopy cover, silt–mud substrate

Gingham GH1 8.2–13.2 9.4–13.5 0.70–1.11 306.7–384.0 6.8–7.4 24.8–27.2 <0.16 Grazed banks, no logs, mud substrate Watercourse

GH2 58.0–60.0 58.0–60.0 0.50–0.90 250.0–379.0 6.8–7.6 23.2–26.9 Very low Fringing cumbungi, many logs, deep silty substrate

Lower Gwydir LG1 7.1–12.7 9.3–15.7 0.38–0.90 252.3–355.3 6.8–7.7 23.5–29.1 0.13–0.39 Grazed banks, few logs, gravel and mud River substrate

LG2 8.4–13.9 13.0–28.2 0.47–0.84 339.7–376.3 6.9–7.5 24.0–26.1 0.11–0.14 Logs across channel, high canopy cover, clay–mud substrate

Mehi River MH1 7.5–11.9 11.7–24.4 0.48–0.85 340.0–384.0 6.8–7.0 26.2–27.7 0.20–0.22 Grazed banks, fringing lignum, mud–clay substrate

MH2 8.5–14.4 16.6–25.0 0.36–1.15 319.0–356.0 6.6–7.0 25.8–26.4 0.04–0.10 Many logs, deep silty substrate

Upstream Gwydir River GW1 30.6–39.6 39.0–55.6 0.43–1.10 193.2–428.7 6.8–8.2 26.2–27.1 0.08–0.50 Many logs, overhanging willow trees, floating vegetation, gravel–mud substrate

GW2 22.2–33.0 22.2–51.9 0.40–1.05 246.7–434.3 7.0–8.2 26.5–28.1 0.09–0.31 Many logs, overhanging willow trees, floating vegetation, gravel bed

Mehi River MH3 12.4–27.2 20.0–37.2 0.48–1.50 228.9–455.0 6.7–8.0 26.6–27.6 0.78–1.24 Riffle and pools, many logs, some canopy cover, gravel bed

* Site dimensions (metres) are based on measurements of bank width, and channel width and depth taken at the position of the fyke nets at each site.

^ Water quality parameters and flow rates are presented to show the range in mean values over both sampling periods (see Spencer 2007; Spencer 2008 for full results).

Site codes: Downstream: Carole Creek CC1 = Sappa, CC2 = Laurella; Gingham GH1 = Jackson, GH2 = Boyanga; Lower Gwydir River LG1 = Wearmatong, LG2 = Allambie; Mehi River MH1 = Derra, MH2 = Telleraga. Upstream sites: Mehi River MH3 = Chinook; Gwydir River GW 1 = Redmill, GW 2 = Beela (see Figure 5).

38 Final report on the Gwydir waterbird and fish habitat study

(ii) Recruitment There was evidence of spawning activity and recruitment in fish species caught during field surveys in the Gwydir Wetlands in 2007–08. Larval specimens were recorded for at least seven fish species during surveys in November 2007, including: freshwater catfish, golden perch, Australian smelt, bony bream, Murray cod, European carp and goldfish. During surveys in November 2007, eight larval freshwater catfish (1.0–2.0 centimetres) and a single larval Murray cod (2.7 centimetres) were recorded at Redmill (GW1), upstream on the Gwydir River and a larval Golden perch (3.2 centimetres) was recorded at Jackson (GH1), on the Gingham Watercourse. A large number of larval bony bream (185 fish), only 0.1– 0.2 centimetres in length, were caught at Allambie (LG2), on the Lower Gwydir River in November 2007. A high proportion of larval and juvenile bony bream (82 per cent of total bony bream caught) were also recorded at Boyanga (GH2), on the Gingham Watercourse in November 2007. Downstream sites near the core wetlands appear to provide important nursery and spawning grounds for bony bream. There was also evidence of some split in habitat use between male and female bony bream between the sampling sites (Figure 8). Similar numbers of male bony bream were observed at all sites in sampling in November 2007, except for Allambie (LG2), on the Lower Gwydir River, where a large cohort of males was observed. In contrast, similar numbers of female bony bream were found at all 11 sites (Figure 8). The highest incidence of sexually mature bony bream (gonad score 3) was observed in samples from Derra (MH1) and Telleraga (MH2), in the Mehi River (Figure 8). Based on information available for size at maturity for eight fish species, juvenile fish were widespread at the survey sites during November 2007 and March 2008 (Table 8). Bony bream were the most widespread and were generally small in size in both November 2007 (8.1 centimetres ± 0.3 s.e.) and March 2008 (7.8 centimetres ± 0.1 s.e.) (Table 6). In March 2008, juvenile bony bream were recorded at all survey sites and the juvenile size class (<15 centimetres) represented 96 per cent of all bony bream caught during the sampling period (Table 8). Juvenile carp were recorded at six of the survey sites but were in greatest numbers at Jackson (GH1) (75 fish) in March 2008. A high concentration of large adult carp was observed at this site in November 2007, which suggests that this area may be an important spawning ground for this alien species. Juvenile spangled perch were caught at five of the sampling sites and in greatest numbers at Jackson (GH1) (25 fish) and Sappa (CC1) (26 fish) in March 2008 (Table 8). Spangled perch were the most abundant fish species in the floodplain waterholes. In total, 794 juvenile spangled perch (<5.8 centimetres) were caught at Tillaloo Waterhole on the Gingham floodplain in March 2008. Gambusia populations had also responded rapidly to higher flows in the system from December 2007–February 2008, as large numbers were found in the floodplain waterholes (838 total fish) and 71 per cent of gambusia caught in the in-channel sites were immature fish (< 2.5 centimetres) (Table 8) (see Spencer 2008).

Final report on the Gwydir waterbird and fish habitat study 39

Table 8. Total number of juvenile fish caught at survey sites in the Gwydir Wetlands (March 2008; n = 11)

Size ^ Site* Common name (cm) CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 Total % Bony bream 15.0 195 58 94 229 277 185 4 5 6 56 61 1,170 95.9 European carp 30.0 3 0 75 16 3 13 0 2 0 0 0 112 93.3 Gambusia 2.5 17 1 3 5 3 0 0 5 0 12 13 59 71.1 Murray cod 40.0 0 0 1 0 0 0 2 0 0 0 0 3 60.0 Spangled perch 5.8 26 1 25 4 2 0 0 0 0 0 0 58 44.6 Goldfish 5.0 0 0 0 10 0 0 0 0 0 0 0 10 19.2 Rainbowfish 3.0 3 2 0 0 0 0 0 0 0 15 110 130 18.6 Golden perch 20.0 0 1 0 0 0 0 0 0 0 0 0 1 12.5

^Size at maturity: Specimens less than this size (standard length) were classed as juveniles. Minimum lengths at maturity for fish species were estimated from Puckridge and Walker (1990); Lintermans (2007); Froese and Pauly (2008). *Site codes (see Figure 5 for site locations): Carole Creek CC1 = Sappa, CC2 = Laurella; Gingham GH1 = Jackson, GH2 = Boyanga; Lower Gwydir River LG1 = Wearmatong, LG2 = Allambie; Mehi River MH1 = Derra, MH2 = Telleraga, MH3 = Chinook. Gwydir River GW1 = Redmill, GW2 = Beela. The overall percentage of juvenile fish caught during the March 2008 surveys is presented for each species (n = number of sites).

40 Final report on the Gwydir waterbird and fish habitat study

(a) Female bony bream

10 1 2 3

5 Number of female Bony Bream

0 CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 Site

(b) Male bony bream

35

30 1 25 2 3 20

15

10

Number of male Bony Bream Bony male of Number 5

0 CC1 CC2 GH1 GH2 LG1 LG2 MH1 MH2 MH3 GW1 GW2 Site

Reproductive status: 1 = gonad present, 2 = medium-sized gonad, 3 = large, swollen gonad (see Methods). *Site codes (see Figure 5 for site locations): Carole Creek CC1 = Sappa, CC2 = Laurella; Gingham GH1 = Jackson, GH2 = Boyanga; Lower Gwydir River LG1 = Wearmatong, LG2 = Allambie; Mehi River MH1 = Derra, MH2 = Telleraga, MH3 = Chinook. Gwydir River GW1 = Redmill, GW2 = Beela.

Figure 8. Distribution and reproductive status of adult bony bream collected from the Gwydir Wetlands (13–19 November 2007; n = 180)

Final report on the Gwydir waterbird and fish habitat study 41

2.3 Conclusions

In total, 45 of the 75 waterbird species recorded historically in the Gwydir Wetlands were observed during field surveys in 2007–08. However, total waterbird numbers were very low and this because of a lack of wetland habitat available to them during a period of extended drought. Waterbird numbers were similar between October 2007 and April 2008, although waterholes on the Gingham floodplain did support large numbers of ducks and small grebes in 2008. There was some evidence for recruitment in native fish species, in particular bony bream, which had a high proportion of juveniles at sampling sites. However, there was limited evidence of breeding and recruitment in waterbird species. The availability of waterbird breeding habitat in the Gwydir Wetlands is limited and few colonial waterbirds were observed during field surveys in 2007–08. The availability of waterbird breeding habitat is a key issue in the Gwydir, as much of the native vegetation has been cleared for agriculture. Environmental flow releases in 2007 have been important for maintaining the integrity of the floodplain vegetation as foraging habitat for waterbird and fish populations; however, large colonial waterbird breeding events depend on significant floodwaters from the upper catchment and local rainfall. Although floodplain areas were used as foraging habitat by waterbirds, they had dried out considerably during March and April 2008 and without high over-bank flows, were unlikely to support breeding activity in the near future. Eleven native fish were recorded during the field surveys and bony bream were the most common native fish species, despite evidence to suggest this species is declining in other parts of the Murray–Darling Basin (Puckridge and Walker 1990). High flows and heavy rainfall from December 2007–February 2008 appeared to trigger spawning and movement of fish species. Numbers of spangled perch and bony bream in March 2008 were higher compared to the November 2007 surveys. Overall, total numbers of alien fish were relatively low across the Gwydir Wetlands, but there were large numbers of gambusia in the floodplain waterholes and carp in the Gingham Watercourse. Native fish species whose larval recruitment may depend on flooding cues were less abundant. This included iconic freshwater fish, such as golden perch and Murray cod, which were found in relatively low numbers during surveys.

42 Final report on the Gwydir waterbird and fish habitat study

3. Water requirements for key species

3.1 Waterbirds

Waterbird abundance and species diversity is strongly dependent on the availability of suitable wetland habitat for feeding and breeding. In general, the movements of resident waterbirds within Australia are poorly understood, but most species are capable of dispersing in response to rainfall and wetland availability (Appendix 3) (Marchant and Higgins 1990; 1993). Extreme examples are the grey teal and pink- eared duck (Malacorhynchus membranaceus), which are highly dispersive and are known to travel great distances inland in response to flooding. In contrast, the Pacific black duck, black swan and musk duck (Biziura lobata) are relatively sedentary in favourable conditions, preferring deep permanent waterbodies. Waterbird species which depend on ephemeral wetlands may be more affected by river regulation, while species which prefer permanent areas of deep open water, such as cormorants and many duck species, may have benefited from artificial habitats, such as farm dams, irrigation channels and impoundments. These artificial habitats are used by some waterbird species during prolonged dry periods and they are thought to have increased the availability of habitat for some species in inland Australia (Marchant and Higgins 1990). The availability of foraging habitat is an important determinant of waterbird breeding success. Most waterbirds prefer wetland habitats with some aquatic vegetation, either as foraging habitat or to provide shelter from the elements or cover from predators. Some species, such as cattle egrets, plumed whistling ducks and Australian wood ducks, although wetland-dependent, can forage away from water in nearby grasslands and woodlands. Other species are entirely aquatic, such as the blue-billed duck and comb-crested jacana (Irediparra gallinacea) and generally do not leave the water to feed. Small waders, such as red-kneed dotterels and black- fronted dotterels (Elseyornis melanops), and freckled ducks and glossy ibis prefer to forage in soft mud or shallow water at the margins of wetlands (Appendix 3) (Marchant and Higgins 1990; 1993). The choice of nesting habitat and height of nests varies between species. However, emergent and fringing aquatic vegetation is important for a number of species. In a review of selected waterbird species that have been recorded breeding in the Gwydir Wetlands, cumbungi (Typha sp.) and lignum was used by at least 14 species as nesting habitat. This analysis was based on records collated in the Handbook of Australian, New Zealand and Antarctic Birds (Marchant and Higgins 1990; 1993) (Appendix 3). Notably, straw-necked ibises rarely nest in trees and most commonly nest on flattened beds of lignum and cumbungi. However, at least 15 species of the selected waterbird species nested in the canopy of tall trees, most commonly eucalypts, belah and river red gums, in or near water, and at least four species of ducks nest in the hollows of large trees (Appendix 3) (Marchant and Higgins 1990; 1993). Islands can also provide protection from ground predators. Most waterbirds commence breeding in early spring (August–September) but many species can start breeding in any month in spring and summer when conditions are favourable. For example, the pink-eared duck, pied cormorant and black swan, are capable of breeding at any time of year if the conditions are suitable (Marchant and Higgins 1990). The stimuli for breeding are often a combination of season, rainfall

Final report on the Gwydir waterbird and fish habitat study 43

and floodwaters. The blue-billed duck and musk duck are the only species which are thought to be entirely seasonal. Waterbirds can nest in solitary pairs, loose colonies with other species, or large dense colonies. Often species of egret, ibis, heron, cormorant and spoonbill form dense mixed colonies concentrated within a small area of wetland (Appendix 3) (Marchant and Higgins 1990; 1993). In total, 50 species have been recorded breeding in the Gwydir Wetlands (see Appendix 1). For most species, there is insufficient information documenting minimum flooding depths for breeding habitat and minimum inundation times required for successful breeding. Although there is some information available on the length of incubation and nestling period for many species, there is limited information documenting the time needed for nest building, laying and post-fledging dependency for many waterbird species (see Appendix 3) (Marchant and Higgins 1990; 1993). This lack of data limits an accurate determination of the total inundation period required to support successful waterbird breeding events. However, it is possible to estimate minimum flooding durations required for 30 waterbird species that have been recorded breeding in the Gwydir Wetlands (see Appendix 3). Using this data, minimum estimates of breeding duration varied between groups of species from about 84 days for grebes, 93–175 days for darters and cormorants, 71–100 days for egrets, 64–77 days for ibis, 80 days for spoonbills, 88–116 days for ducks, 65–93 days for small resident waders and 68–93 days for water hens (Marchant and Higgins 1990; 1993).

3.2 Fish

Native fish species have specific water requirements that determine their distribution and recruitment success (Table 9). Most of the fish species recorded in field surveys of the Gwydir Wetlands are widespread in the Murray–Darling Basin, with the exception of the Murray cod, Murray–Darling rainbowfish, freshwater catfish and unspecked hardyhead, which now have a patchy distribution (Lintermans 2007). They also prefer lowland rivers and slow moving, turbid waters in complex habitats that have a mixture of submerged logs and aquatic and fringing vegetation (Table 9). Some species have specific habitat requirements. For example, freshwater catfish generally prefer sand and gravel habitats, while Murray cod prefer deep pools with submerged trees (Allen et al. 2002; Lintermans 2007). Mobility is important for the dispersal of young fish and spawning in some species, such as the golden perch and silver perch, which are capable of large scale migrations upstream to their spawning grounds (Reynolds 1983). Other species, such as gudgeons, catfish and hardyheads, are relatively sedentary and only have small home ranges (1– 2 kilometres) (Young 2001; Lintermans 2007) (Table 9). Most species have wide tolerances to environmental conditions. However, Australian smelt, Murray–Darling rainbowfish, spangled perch and golden perch are sensitive to low water temperatures, and bony bream are intolerant of low dissolved oxygen concentrations (Milton and Arthington 1985; Lintermans 2007). High salinity also has negative effects on juvenile freshwater catfish and unspecked hardyheads (Lintermans 2007; Wedderburn et al. 2008). Increased turbidity may also adversely affect the eggs of freshwater catfish – they lay large non-adhesive eggs in gravel nests (Table 9) (Lintermans 2007). Native fish species have specific flow requirements for growth. In the Gwydir Wetlands, flow volumes had significant effects

44 Final report on the Gwydir waterbird and fish habitat study

on growth rates of two native fish species, with juvenile Australian smelt and bony bream growing fastest in areas of low flow (Heagney et al. 2009). In the presence of suitable habitat, cues for spawning in native fish can be seasonal increases in water temperature, day length and flow (Humphries et al. 1999). In an unregulated system this normally coincides with spring and summer months. For example, bony bream have a strong seasonal cycle which is related to water temperature and day length and they spawn in October to December in NSW in warm shallow waters (Puckridge and Walker 1990). In unregulated systems, the peak spawning in bony bream occurs two to three months after the flood peak (Puckridge and Walker 1990). For golden perch and spangled perch, spawning is strongly flood-related because the eggs of these species are buoyant and larvae are free-swimming (Table 9) (Llewellyn 1973; Lintermans 2007). The spangled perch is a very hardy species and during heavy rain it has been observed swimming across shallow water to reach new habitat (Lintermans 2007). It may also aestivate during drought periods (Allen et al. 2002). Recruitment refers to the survival of young fish and entry of new individuals into populations (Young 2001). Larval development in less common native fish species, such as silver perch, is largely flood-dependent. The survival and growth of larval fish depends on predation, availability of suitable habitat, water quality and food quantity and quality. Declines in these species in the Murray–Darling Basin may be related to recruitment failures (Puckridge and Walker 1990). Most native fish species are carnivorous to some degree and only bony bream are truly detritivores, consuming mostly benthic algae (Bunn et al. 2003). Adult freshwater catfish, golden perch and Murray cod are large predators which prey on freshwater shrimps, prawns, yabbies and smaller fish (Table 9) (Davis 1977a; Lintermans 2007). Larvae of all native fish are carnivorous and consume zooplankton and aquatic insect larvae (Young 2001; Lintermans 2007). Fecundity varies between species, but is high in bony bream, spangled perch and gambusia which mature at an early age (Puckridge and Walker 1990; Lintermans 2007) (Table 9). Gambusia can produce about 50 live young and up to nine batches a year (Lintermans 2007). Freshwater catfish, golden perch and Murray cod have relatively low population resilience, with minimum population doubling times of between 4.5–14 years (Froese and Pauly 2008). Age at maturity for these species is 3–5, 2–4 and 4–6 years respectively, while Gambusia reach maturity within two months and spangled perch within a year (Table 9) (Allen et al. 2002; Lintermans 2007; Froese and Pauly 2008). Declines in the duration of flooding may have impacted on native fish populations in the Gwydir Wetlands. Although the optimal duration for flooding is not well- understood for most species, it should be long enough to cover the period from ovulation to metamorphosis for multiple species (Gehrke 1991 from Siebentritt 1999). For example, spangled perch eggs take two days to hatch at temperatures between 23–26 degrees Celsius and a further 24 days after hatching to reach a post-larval stage (Llewellyn 1973), and golden perch require 33–34 hours to hatch eggs (at 20– 25 degrees Celsius) and are 18–20 days old at the end of larval development (Lake 1967). Flooding duration needs to be longer for Murray cod, which require six to seven days to hatch their eggs (at 22-25ºC) and an additional 25 days for larvae to mature (Lake 1967).

Final report on the Gwydir waterbird and fish habitat study 45

Although the number of alien fish species was relatively low during field surveys in the Gwydir Wetlands, alien species can have negative impacts on water quality, aquatic vegetation and native fish recruitment (Lintermans 2007). Large floodplain wetlands, such as the Gwydir Wetlands, are thought to be significant ‘hotspots’ for carp breeding (Lintermans 2007). Alien fish species are generally highly fecund and have less specific flow requirements (Table 9) (Lintermans 2007). Carp, goldfish and gambusia have wide environmental tolerances but prefer slow moving, warm waters. Notably, carp can withstand very low dissolved oxygen and goldfish tolerate wide ranges in salinity (Allen et al. 2002). Farm storages can be used by alien species, which move out of these areas during high flow periods to spawn in natural habitats (Siebentritt 1999). Carp are benthic feeders and so resuspend sediments, increasing turbidity and inhibiting macrophyte and algal growth, and can compete directly with native fish when habitat is limited (Young 2001) (see section 1.2.4).

46 Final report on the Gwydir waterbird and fish habitat study

Table 9. Life history and habitat requirements of fish species recorded in the Gwydir Wetlands

Habitat Length Age at Size at Population Water Temp Spawning preferences in mm maturity maturity in resilience^ quality range Species Distribution Type Timing Fecundity Trophic Dietary items (movements) (maximum) (lifespan) mm sensitivity in MDB (temp) level Australian Widespread Deep pools, riffles 40–60 1 yr Insufficient High Low temp 10–25°C Seasonal Spring– Low Pelagic Terrestrial and smelt and abundant and fringing (100) (3 yrs) data (>15°C) early (100–1,000 carnivore aquatic insects, at low- and mid- vegetation (some summer eggs), eggs microcrustaceans altitudes upstream migration) adhesive Bony bream Widespread Still, or slow-flowing 150–200 1–2 yrs in 159 (males), Medium Wide 9–38°C Seasonal Oct–Dec High Algal Detritus, algae and and very turbid streams (daily (480) males and 199 tolerances (21–23°C) (33,000– detritivore plant material, abundant in movements for new 2 yrs in (females) but sensitive 880,000 eggs), juveniles feed on lowland rivers habitat/ spawning) females to low eggs adhesive microcrustaceans (10 yrs) dissolved oxygen Freshwater Widespread in Slow-flowing <500 3–5 yrs Insufficient Low High salinity 5–25°C Multiple, Jan–Mar Variable Benthic Freshwater catfish lowland slow- streams, sand, mud (900) (8 yrs) data (juveniles), seasonal (2,000-26,000 opportunistic shrimps, prawns, moving rivers, and gravel habitats low temp (20–24°C) eggs), large carnivore yabbies, molluscs, populations (sedentary) and non-adhesive small fish (e.g. carp declining in increased eggs settle in gudgeons), MDB turbidity gravel nest, juveniles feed on male guards aquatic insects eggs Golden perch Widespread in Prefers warm, slow- 40–50 2 yrs in 200–300 Low Low temp 4–35°C Seasonal– Spring– High (500,000 Opportunistic Shrimps, yabbies, lower- and mid- moving, turbid (760) males, 4 yrs (male), flood- summer eggs), eggs carnivore small fish and reaches of streams (adults in females 400 dependent semi-buoyant benthic aquatic MDB, declines migrate large (20 yrs) (female) (>20°C) insect larvae, in some areas distances [2,000 km] juveniles feed on upstream to spawn, zooplankton juveniles disperse over floodplain) Murray cod Formerly Deep pools, with 600–1,000 4–6 yrs 400–600 Low Increased Insufficient Seasonal Spring– Large, Carnivore Fish, yabbies and widespread in fallen trees (migrate (1,800) (48 yrs) turbidity data (>15°C) summer adhesive eggs, (sit and wait frogs, juveniles low- and mid- large distances male guards predator) feed on altitude areas of upstream to spawn, eggs, larvae zooplankton MDB, otherwise highly flood- distribution now sedentary) dependent patchy, listed as a threatened species

Final report on the Gwydir waterbird and fish habitat study 47

Habitat Length Age at Size at Population Water Temp Spawning preferences in mm maturity maturity in resilience^ quality range Species Distribution Type Timing Fecundity Trophic Dietary items (movements) (maximum) (lifespan) mm sensitivity in MDB (temp) level Murray- Formerly Slow-flowing areas, 70 10–12 mths 30 Medium Low temp 10–25°C Seasonal Spring– Low Pelagic, Aquatic and Darling widespread in aquatic vegetation (110) (no data) (>20°C) summer (35–333 eggs), omnivore terrestrial rainbowfish lowland rivers, and submerged logs eggs adhesive invertebrates, now patchy (some migration, some filamentous distribution schooling species) algae

Spangled Very Wide habitat 150 1 yr 58 (male), Medium Wide 5–44°C Seasonal Nov–Feb High Primarily Aquatic insects, perch widespread, preferences, may (330) (no data) 78 (female) tolerances (20–26°C) (24,000- carnivore shrimps, prawns, most common aestivate in but sensitive 113,200 eggs), microcrustaceans, in north and droughts (highly to low temp small, fish and some plant western mobile, disperses demersal, non- material portions of across floodplain adhesive eggs, MDB, rare in after heavy rain) flooding south maximises recruitment Unspecked Restricted to Margins of slow- 50–60 Insufficient Insufficient High High salinity Insufficient Multiple, Oct–Feb Low Carnivore Small insects; hardyhead lowland areas moving waters, with (78) data data suspected data seasonal (20–107 eggs), mosquito larvae and most aquatic vegetation (24°C) eggs demersal, and common in (schooling species, filamentous microcrustaceans northern MDB, some local adhesive declines in movements) strands southern range Western carp Widespread, Slow, still waters, 40 1 yr Insufficient High Insufficient Insufficient Seasonal Late Eggs laid on Mid-water/ Copepods, aquatic gudgeon some decline in associated with (70) (no data) data data data (22.5°C) spring– aquatic benthic insects, basin (rare in aquatic vegetation summer vegetation, carnivore cladocerans and South Australia) (unknown) male guards ostracods, some eggs plant material Midgley’s Common Prefers habitat with 40 Insufficient Insufficient High Insufficient Insufficient Seasonal Spring– Insufficient Carnivore Microcrustaceans, carp through aquatic vegetation, (40) data data data data (no data) summer data e.g. cladocerans gudgeon northern MDB woody debris, and copepods overhangs (schooling fish) Lake’s carp Relatively Slow-flowing 40 Insufficient Insufficient High Insufficient Insufficient Seasonal Oct–Dec Insufficient Carnivore Small crustaceans, gudgeon common in waters, near aquatic (40) data data data data (no data) data insects, fish eggs northern MDB vegetation (unknown)

48 Final report on the Gwydir waterbird and fish habitat study

Habitat Length Age at Size at Population Water Temp Spawning preferences in mm maturity maturity in resilience^ quality range Species Distribution Type Timing Fecundity Trophic Dietary items (movements) (maximum) (lifespan) mm sensitivity in MDB (temp) level European Widespread in Wide tolerances, 200–1,000 2–3 yrs in 300 (male) Medium Wide 3–35°C Seasonal Spring– High Benthic Zooplankton, carp* slow lowland prefer warm slow- (1,200) males and 350 tolerances, (17–25°C) summer (>300,000 omnivore freshwater insect rivers flowing (move to 3–4 yrs in (female) esp. low eggs), eggs larvae, lowland wetlands to females dissolved adhesive, laid crustaceans, spawn) (38 yrs) oxygen in clumps molluscs, some plant material Gambusia* Widespread Wide tolerances, 35 (male), 2 mths 25 High Wide 15–35°C Multiple, Summer High – live Carnivore Small freshwater and abundant in slow-flowing waters, 60 (female) (no data) tolerances seasonal young (50 invertebrates, MDB, common edges of vegetation (80) young per terrestrial insects, in slow-flowing (non-migratory) batch; 9 eggs and larvae of waters and batches a native fish, frog shallow year) eggs wetlands Goldfish* Widespread, Slow-flowing areas, <200 No data 100–150 Medium Wide 0–41°C Seasonal Summer Eggs laid in Omnivore Small crustaceans, especially in often associated (590) (41 yrs) generally tolerances, (17–23°C) freshwater freshwater insect impoundments with aquatic (30–50 esp. salinity plants larvae, plant vegetation (non- recorded) material and migratory) detritus

* Alien species MDB = Murray–Darling Basin ^Population resilience – minimum population doubling times (Froese and Pauly, 2008): high <15 months; medium 1.4–4.4 years; low 4.5–14 years. Sources: Llewellyn (1973); Davis (1977a; 1977b); Milton and Arthington (1985); Puckridge and Walker (1990); Allen et al. (2002); Lintermans (2007); Froese and Pauly (2008); Wedderburn et al. (2008)

Final report on the Gwydir waterbird and fish habitat study 49

3.3 Implications for management

It is vital to restore connectivity and reinstate flow variability in the Gwydir Wetlands to rehabilitate habitats for waterbird and fish populations. The availability of large flood events and suitable breeding habitat are significant limiting factors for colonial waterbird species in the Gwydir Wetlands. Numbers of alien fish are relatively low in the Gwydir Wetlands but the abundance of native fish is dominated by opportunistic, highly fecund species. Habitat availability and recruitment for less common native fish species could be maximised by removing barriers to fish passage, reinstating natural flow regimes and improving water quality. In light of the water requirements of waterbirds and native fish species discussed above, it is recommended that the following principles be incorporated into habitat rehabilitation strategies for the Gwydir Wetlands (see section 4 for detailed recommendations): • Restore connectivity between floodplain areas and river channels. • Time flows (spring–summer) for sufficient duration to maximise waterbird breeding (> three months for ground-nesting ibis species and five to six months for tree- nesting egrets and herons) and native fish spawning. • Modify or remove barriers to fish passage. • Maintain frequent inundation of key wetland vegetation communities that provide foraging and breeding habitat for waterbirds and fish. • Protect dead trees and assist with the regeneration of tree species near wetland habitats that can provide breeding and roosting habitat for waterbird species. • Promote large- and small-scale habitat diversity, i.e. at the floodplain scale (e.g. ephermal shallow vegetated and open water habitats) and microhabitat scale (e.g. aquatic and submerged vegetation, open water and soft muddy margins). • Reduce river bank erosion to improve water quality. • Revegetate riparian zones and manipulate water levels to encourage the establishment of ephemeral vegetation. • Remove or exclude alien fish species. • Develop education initiatives that promote wetland conservation and sustainable land management techniques. • Maintain monitoring programs and support further research that investigates water requirements for native waterbird and fish populations and methods for controlling introduced species.

50 Final report on the Gwydir waterbird and fish habitat study

4. Recommendations for management

4.1 Priorities for rehabilitation

The Gwydir Wetlands are clearly showing signs of stress as a result of extended periods of drought and inappropriate land and water management practices. Indicators of stress include the high number of feral animals, invasive plant species, declines in wetland vegetation condition, low numbers of waterbirds dominated by species that favour artificial habitats and a fish community dominated by common opportunistic native species and the presence of alien fish species. To maintain its function and biodiversity values, it is essential that remaining wetland areas in the Gwydir are conserved as priority habitats for native waterbird and fish populations. Key ecological assets that have been identified in the Gwydir Wetlands include threatened species, colonially nesting waterbirds, the Lower Gwydir River and Gingham wetlands and native fish species (Johnson 2001).

4.1.1 Key species

Nine threatened waterbird species and at least two threatened native fish species have used the Gwydir Wetlands for part of their life cycle (Table 10). The Gwydir Wetlands also supports at least nine migratory shorebirds (Appendix 1) during their non-breeding season in Australia and probably acts as a staging site for many of these species during their southward migration. Most notably, the Gwydir Wetlands has supported large colonial waterbird breeding events and was formerly a significant breeding site for straw-necked ibis, intermediate egrets, rufous night heron and glossy ibis in the Murray–Darling Basin (Spencer 2010). Native fish are a key food source for colonial waterbirds and in turn are an important component of the aquatic food web, which depends on freshwater invertebrates such as yabbies, prawns/shrimps and zooplankton.

Final report on the Gwydir waterbird and fish habitat study 51

Table 10. Threatened waterbird and fish species that have been recorded in the Gwydir Wetlands

Species Status^ Habitat requirements * State National IUCN Australasian V EN Shallow vegetated swamps, territorial nesters in tall bittern and short sedges Black bittern V LC Prefer well-vegetated wetlands and nests in trees

Black-necked E NT Shallow swamps and waterholes, nest in tall trees stork Blue-billed duck V Prefer deep permanent open water with dense vegetation, nest in rushes, sedges and lignum Brolga V LC Shallow wetlands and adjacent grasslands, nests are constructed on a mound of grass and sticks Comb-crested V LC Prefer permanent waterholes with floating vegetation, jacana polyandrous females defend nests on floating vegetation Freckled duck V LC Prefer brackish to hyposaline wetlands, nest in lignum, roost in dead trees Magpie goose V LC Shallow swamps and grasslands, colonial nesters, nests are constructed on mounds of lignum and cumbungi Australian E V Shallow, vegetated temporary wetlands with muddy painted snipe edges, nests in a shallow scrape Murray cod V CR Wide range of warm water habitats, prefer woody debris and deep holes in rivers, increased flow in winter triggers spawning Olive perchlet E Inhabit vegetated edges of wetlands and rivers, often associated with woody and aquatic vegetation in slow flowing areas Purple-spotted E Prefer slow moving, deeper habitats, often associated gudgeon with covers, such as rocks and aquatic vegetation Silver perch V VU Not well-known, but prefer areas of rapid flow in rivers and lakes

^Status: State (TSC Act), National (EPBC Act) and International Union for Conservation of Nature (IUCN): V = vulnerable, E/EN = endangered, CR = critically endangered, NT = near threatened, LC = least concern.

*Habitat requirements for threatened waterbird species are based on Garnett and Crowley (2000) and for fish species on Allen et al. (2002) and Lintermans (2007).

52 Final report on the Gwydir waterbird and fish habitat study

4.1.2 Key waterbird habitat

Based on a historical review of waterbird habitat use in the Gwydir Wetlands (Spencer 2010) recent field surveys (Spencer 2007; 2008) and a project debrief the following areas were identified as important habitat for waterbirds (see Figures 3 and 9, and Appendix 2 for site locations):

Breeding habitat

• Floodplain waterholes − Baroona Waterhole (little pied cormorant, darter, little black cormorant, white- necked heron (Ardea pacifica), rufous night heron and small grebes) − Tillaloo Waterhole (glossy ibis, Australian white ibis and small grebes) − Talmoi Waterhole (small grebes) − Derra Waterhole (small grebes and ducks). Large stands of lignum at this site could potentially provide waterbird breeding habitat.

• In-channel lagoons − Gingham Waterhole (egrets, rufous night herons, great-crested grebe (Podiceps cristatus), white-necked heron, darter, magpie geese, musk duck, cormorants, Eurasian coot, water hens, blue-billed duck) − Boyanga Waterhole (glossy ibis, little pied cormorant, rufous night heron, white- necked heron, yellow-billed spoonbill).

• Floodplain wetlands with sedgelands, stands of cumbungi, lignum, belah, coolibah and river red gum on the Lower Gwydir River and Gingham Watercourse: − Yarrol (straw-necked ibis, Australian white ibis, spoonbills, little egret, cattle egret, intermediate egret, great egret, little black cormorant, little pied cormorant, little bittern, Australasian bittern, rufous night heron, magpie geese and ducks) − Lynworth (glossy ibis, Australian white ibis, straw-necked ibis, egrets, black swan, royal spoonbill) − Old Dromana (ducks, grebes, cormorants, herons, ibis, egrets, black-winged stilt and dotterels) − Bunnor (brolga, black-necked stork, magpie geese) − Gwydir Raft (magpie geese, rufous night herons) − Munwonga – large stands of lignum could provide breeding habitat for ibis species (D. Albertson (DECCW) pers. comm. June 2008).

Final report on the Gwydir waterbird and fish habitat study 53

Feeding habitat Large areas of feeding habitat are required to sustain waterbird breeding events. It is essential to maintain the condition of the Gwydir wetlands during dry periods as refuge sites for waterbird species and to maintain their integrity in readiness for significant flood events that could initiate colonial waterbird breeding. Dry conditions in 2007–08 limited waterbird numbers in the Gwydir and the ability to assess floodplain habitats. However, the following areas were identified as important feeding habitats for waterbird species:

• Floodplain waterholes − Baroona Waterhole − Tillaloo Waterhole − Talmoi Waterhole − Whittakers Lagoon.

• In-channel lagoons − Gingham Waterhole − Boyanga Waterhole − Mary Brand Park Lagoon.

• Floodplain areas with freshwater meadows, sedgelands and stands of cumbungi on the Lower Gwydir River and Gingham watercourse, in particular: − Old Dromana − Bunnor and Westholme − Crinolyn − Jackson − Goddard’s Lease − Pear Paddock and Racecourse Lagoon − Lynworth − Wandoona.

54 Final report on the Gwydir waterbird and fish habitat study

4.1.3 Key fish habitat

Field surveys in 2007–08 indicated that in-channel sites nearest the core wetlands, such as Allambie on the Lower Gwydir River and Boyanga Waterhole on the Gingham Watercourse, (Figure 5) provided important spawning and refuge habitat for native fish, such as bony bream and spangled perch. Fish recruitment is complex, but depends on successful spawning, hatching and survival of young fish. Effective management will need to promote and create elements of the natural flow regime that lead to consistent annual recruitment in native fish species. The survival of larval spangled perch and golden perch can be promoted by the provision of floodplain wetlands as feeding habitat. Enhancing connectivity between in-channel sites and floodplain habitats is essential for facilitating access for native fish larvae. The field surveys also indicated that the Mehi River may be an important source of recruitment for native fish species, such as Murray cod and golden perch. Upstream areas of the Gwydir River were also important sites for Murray–Darling rainbowfish and Australian smelt, which may favour areas with aquatic macrophytes. Preserving and restoring structural features of the wetlands and main channels should be a high priority for native fish conservation. For example, filamentous algae provides food for bony bream and cover for smaller fish such as rainbowfish, smelt and carp gudgeons, while logs and snags provide important habitat for Murray cod.

Final report on the Gwydir waterbird and fish habitat study 55

Figure 9. Historical locations of waterbird breeding habitat in the Gwydir Wetlands (1921–2005)

56 Final report on the Gwydir waterbird and fish habitat study

4.2 Potential on-ground works

There are a number of on-ground works that could be considered for improving habitats for waterbirds and fish in the Gwydir Wetlands: 1. Install fishways at major weirs and regulators in the Gwydir system to promote native fish passage. This is a high priority for the Tyreel regulator (Figure 2), which has been identified as a significant barrier to fish passage in the Gwydir River (Mallen-Cooper 2000). The narrow path between the gates of the regulator increases flow and this may inhibit some native species trying to move upstream (Siebentritt 1999). Tyreel Weir is also a barrier for fish moving between the wetlands and upstream habitats during low-flow periods (Mallen-Cooper 2000). 2. Modify existing rock weirs in the Lower Gwydir River and Gingham Watercourses to assist fish passage. Many of these rock weirs are designed to reduce flow rates thereby assisting overland flow and benefitting surrounding wetland vegetation. While these weirs have been engineered in accordance with I&I NSW requirements for fish passage, they remain impassable for fish species during periods of low flow. 3. Modify boundary fences (e.g. by increasing mesh sizes) that cross channels and floodplain waterholes (e.g. Baroona Waterhole) to assist fish passage. 4. Continue regular inundation of core wetland vegetation on the Lower Gwydir River and Gingham Watercourses. 5. Protect priority waterbird breeding habitat, including cumbungi and lignum and wetland trees, from browsing by domestic animals. 6. Investigate and develop strategies that specifically target the removal of foxes and cats in the Gwydir Wetlands. These feral animals were observed frequently in the Gwydir Wetlands during field surveys in 2007–08. 7. Create waterbird breeding habitat in the Gwydir Wetlands. For example, Talmoi Waterhole is a large waterbody that has not been used extensively as breeding habitat in the past (Spencer 2010). However, predator-free islands may make this site more attractive as breeding habitat for waterbirds. 8. Carry out rehabilitation works in cleared colonial nesting areas on the Yarrol property, on the Gingham Watercourse. Cleared timber could be used to provide temporary nesting platforms until vegetation regenerates. Artificial platforms have been adopted by white ibis in other wetlands in Australia (Marchant and Higgins 1990) and could be trialled as temporary nesting platforms in areas which were historically used for breeding. 9. Install a reliable gauging system at key sites to monitor breeding events as required. Real-time measurements of water depth and duration are required at key waterbird breeding and feeding sites to assist with the management of colonial waterbird breeding events. 10. Revegetate riparian zones and reduce stock access along the Lower Gwydir River, Gingham and Mehi channels. These works will improve water quality in the main tributaries.

Final report on the Gwydir waterbird and fish habitat study 57

11. Increase habitat diversity in the Gingham and Lower Gwydir River channels by placing logs and snags in uniform stretches of the channels, for example at Jackson, on the Gingham, to increase habitat diversity for fish species (see MDBC 2003). 12. Encourage the regeneration of coolibahs on the Gingham and Lower Gwydir River floodplain. These areas contain extensive areas of dead coolibah trees that show limited signs of regrowth. 13. Maintain connectivity between large waterholes on the Gingham Watercourse (Baroona, Tillaloo, Talmoi, Boyanga and Gingham) (Figure 3). Sedimentation may be a threat to inflows into these waterholes in the future. 14. Install devices to exclude carp from accessing spawning grounds in the Gingham Watercourse. Trial carp separation cages or screens (Stuart et al. 2006) at Jackson and Westholme to prevent carp travelling further downstream. 15. Trial a carp removal program, which systematically targets carp spawning aggregation areas, in spring and summer months along the Gingham Watercourse and in farm storages that provide refuge for this alien species. This removal program should be run alongside a monitoring program to track the effectiveness of this work (see section 4.4). 16. Install educational signs on public lands, such as Mary Brand Park Lagoon in Moree and Whittakers Lagoon, to promote wetland conservation and community engagement. 17. Provide an education program about using fish exclusion screen technology to reduce the uptake of juvenile and adult fish into extractive pumps and irrigation infrastructure. 18. Establish a ‘Bird routes of Moree’ publication to promote the Gwydir Wetlands and to provide information on the locations of waterbird species in and around the Gwydir Wetlands.

4.3 Recommendations for monitoring

This project provides baseline information on the distribution and abundance of waterbirds and native fish in the Gwydir Wetlands, supplementing limited data available for waterbird and fish populations in this system (see section 1.2.3). An ongoing monitoring program is required to measure changes in waterbird and fish assemblages and for the detection of threatened species in the Gwydir Wetlands. Potential options for monitoring waterbird and fish populations in the Gwydir Wetlands are summarised in Table 11. Techniques are listed in order from maximum to minimum survey coverage, and according to survey intensity (high, medium and low). The advantages and disadvantages of each survey technique and potential outcomes are also listed. In future monitoring programs, it would be beneficial to continue surveying sites used in the Gwydir waterbird and fish study, or if resources are limited, at least a subset of these sites. This will provide greater ability to detect changes in waterbird and fish populations and their habitats in response to management actions and/or environmental changes.

58 Final report on the Gwydir waterbird and fish habitat study

Waterbirds

A combination of aerial and ground surveys is the preferred method for monitoring waterbird populations in floodplain wetlands (Baldwin et al. 2005). Aerial surveys can be used to determine the distribution of birds and for making a rapid assessment of relative abundance (Kingsford 1999; Kingsford et al. 2008) and to locate breeding colonies. Ground surveys can provide more accurate data on smaller scale abundances, species composition and the timing and extent of breeding events (Baldwin et al. 2005). In addition to a regular census of waterbird species (either at a bi-annual, annual or two- to five-year frequency) in the Gwydir Wetlands, ad hoc monitoring of colonial waterbird breeding will also be required at an event-based scale (Table 11).

Fish

A combination of methods is required to adequately sample fish populations in wetlands (Baldwin et al. 2005). Electrofishing is an active sampling method and is the preferred method of sampling in I&I NSW research programs (Harris and Gehrke 1997). This method is difficult in shallow wetlands or channels where underwater snags and rocks make boat-electrofishing impractical and backpack-electrofishing often dangerous. Alternative techniques are often a combination of bait traps, seine nets and fyke nets (Baldwin et al. 2005). These methods can be used to give some measure of species richness, total abundance and the ratio of native and alien fish species.

Water quality

Water quality monitoring is essential for measuring the health of the aquatic community and for detecting agal blooms and toxicants, such as metals and organic compounds in the system (Baldwin et al. 2005). Monitoring multiple water quality parameters (such as turbidity, conductivity, temperature, dissolved oxygen [DO], pH, total phosphorus [P] and nitrogen [N], chlorophyll, metals and organic compounds) at regular intervals would provide information on how water quality varies during low and high flow periods in the main tributaries. This data may help explain differences in fish assemblage distribution. For full recommendations on methods for measuring water quality in surface waters in Australia see Baldwin et al. (2005) and Environment Australia (2000).

Final report on the Gwydir waterbird and fish habitat study 59

Table 11. Potential options for monitoring waterbird and fish populations and their habitats in the Gwydir Wetlands.

Component Survey Survey Monitoring intensity Advantages/ Potential outcomes type techniques disadvantages High Medium Low Waterbirds Census Aerial survey with Annual, in spring Annual, in spring Every 2–5 years, Can be compared to the Detect changes in replicate ground and summer only in spring baseline data set. distribution and counts Replicate ground counts abundance of increase chances of waterbird species detecting cryptic species. and breeding occurrence. Aerial survey with Annual, in spring Annual, in spring Every 2–5 years, Can be compared to the Detect changes in single ground counts and summer only in spring baseline data set. Single distribution and ground counts are only a abundance of snapshot and can be waterbird species biased by time-of-day and breeding effects. occurrence. Aerial survey only Annual, in spring Annual, in spring Every 2–5 years, Rapid and cost-effective Detect changes in and summer only in spring survey technique but distribution and cryptic species may not abundance in be detected. waterbird species and breeding occurrence. Ground counts only Annual, in spring Annual, in spring Every 2–5 years, Replicate counts most Detect changes in and summer only in spring beneficial, but ground distribution and counts coverage limited abundance in and more time- waterbird species consuming than aerial and breeding surveys. occurrence.

60 Final report on the Gwydir waterbird and fish habitat study

Component Survey Survey Monitoring intensity Advantages/ Potential outcomes type techniques disadvantages High Medium Low Waterbirds Colonial Aerial survey Surveys at ten-day Three surveys – Single survey in This method is useful for Information on total waterbird intervals over the at start, peak and peak breeding locating colonies, nesting area, nesting breeding breeding period end of breeding period determining flood extent, density, nesting events period instantaneous counts of period, clutch size nests and for and breeding photographing colonies success. for more detailed counts. Ground counts Fortnightly surveys Monthly surveys Single survey of Site access may be More detailed of breeding of breeding colonies during difficult and counts may information on timing colonies colonies peak breeding be time-consuming. Need of breeding events, period experienced personnel to flooding depth, limit disturbance at hatching and colony. fledging dates, and breeding success. Fish Census Multiple methods Annual, in spring Annual, in spring Every 2–5 years, Can be compared to the Detect changes in (bait traps, large and and summer (to or summer in spring or baseline data set. distribution, small fyke nets, and coincide with summer Multiple techniques are abundance and size seine nets) environmental flow required for detecting classes, and effects events if possible) small and large fish of flow regime species. Single method (large Annual, in spring Annual, in spring Every 2–5 years, Nets are easy to install Detect changes in and small fyke nets) and summer (to or summer in spring or and effective for catching distribution, coincide with summer carp, which can be abundance and size environmental flow removed from the classes, and effects events if possible) system. of flow regime. Electro-fishing in Annual, in spring Annual, in spring Every 2–5 years, Some rare and small fish Some ability to upper reaches of the and summer (to or summer in spring or may be missed, but this determine changes Gwydir and Mehi coincide with summer technique is effective at in fish communities Rivers environmental flow catching large species that may use wetland events if possible) and is a rapid habitats further assessment technique. downstream.

Final report on the Gwydir waterbird and fish habitat study 61

Component Survey Survey Monitoring intensity Advantages/ Potential outcomes type techniques disadvantages High Medium Low Water Monitoring Full range of Daily (standard Monthly intervals Seasonally (at Time consuming if data Information on quality parameters (turbidity, time of day) (at standard time standard time of collection not automated. changes in water conductivity, temp, of day) day) Rapid detection of quality under high DO, pH, [N], [P], elevated levels of toxic and low flows in the chlorophyll, metals, metals, organic system, incidence of organic compounds) compounds and nutrient pollution events and loads in high intensity assists with monitoring. identification of point sources. Limited range of Daily (standard Monthly intervals Sesonally (at Time consuming if data Information on parameters (turbidity, time of day) (at standard time standard time of collection not automated. changes in water conductivity, temp, of day) day) Could be used to explain quality under high DO, pH) distribution of fish and flows in the assemblages. system. Limited range of Annually, in spring Annually, in Every 2–5 years, Can be compared to the May be possible to parameters (turbidity, and summer (to spring or summer in spring or baseline data set but only detect changes in conductivity, temp, coincide with summer provides a snapshot of water quality and DO, pH) alongside environmental flow water quality in the effects on fish fish surveys events if possible) system and may not help communities. to explain distribution of fish assemblages.

62 Final report on the Gwydir waterbird and fish habitat study

4.4 Further research

There are considerable knowledge gaps about the Gwydir Wetlands in relation to the effects of barriers to fish passage, the impacts of introduced species on native waterbird and fish populations, the condition and extent of waterbird breeding habitat, and the presence of threatened species and their habitat requirements. The following studies could be used to address some of these knowledge gaps: 1. Identify ways of increasing fish passage through the Gwydir Wetlands. 2. Determine movements and survival rates of native fish larvae in the Gwydir system. 3. Identify important drought refugia sites for native fish in the Gwydir system to support decision-making about environmental water during extremely dry periods. 4. Undertake research to determine the effect that undershot weirs and regulators (e.g. Tyreel, Tareelaroi and Combadello) are having on the adult, juvenile and larval mortality rates of native fish. 5. Survey fish communities in farm storages and the effects of irrigation infrastructure on fish passage and recruitment in the Gwydir Wetlands. 6. Monitor the effectiveness of a carp eradication program and exclusion devices in the Gingham Watercourse on native fish communities. 7. Investigate movements and home-ranges of carp in the Gwydir system. 8. Investigate the effects of gambusia on native fish and frog populations. 9. Investigate conditions for establishment, persistence of seed bank, growth rates and water requirements for lignum. This vegetation community is a key breeding habitat for waterbirds and this study will provide important information that could assist with the rehabilitation of lignum stands on Yarrol and other parts of the Gwydir wetlands. 10. Undertake explorative surveys to determine the presence of threatened waterbird and fish species. 11. Investigate levels of site fidelity in waterbird and fish species recorded in the Gwydir Wetlands. 12. Undertake diet studies for key waterbird species, such as colonial waterbirds. 13. Monitor the success and water requirements of waterbird breeding events in the Gwydir Wetlands as they occur. 14. Determine the habitat requirements and distribution of carp gudgeon species (Hypseleotris spp.) in the Gwydir Wetlands (it is likely that many species from this genus are present in the Gwydir system and are yet to be identified). 15. Undertake further monitoring of the effects of environmental flow releases on spawning and recruitment in native fish populations. 16. Undertake field surveys to quantify abundance and distribution of native frog and reptile species in the Gwydir Wetlands. These species are an important food source for many waterbirds and large native fish species. 17. Investigate levels of heavy metals and toxic chemicals and their effects on fish-eating waterbirds and large predatory fish in the Gwydir River.

Final report on the Gwydir waterbird and fish habitat study 63

References

Allen, G.R., Midgley, S.H. and Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australia Museum, Perth. Bailey, R.F. 1934. ‘New Nesting Records of Glossy Ibis’. Emu Vol XXXIII: 279–291. Baldwin, D.S, Nielsen, D.L., Bowen, P.M. and Williams, J. 2005. Recommended Methods for Monitoring Floodplains and Wetlands. Murray–Darling Basin Commission, Canberra. Baumgartner, L.J. 2004. The effects of Balranald Weir on spatial and temporal distributions of lower Murrumbidgee River fish assemblages. NSW Fisheries Final Report Series No. 65. June 2004. NSW Fisheries, Narrandera Fisheries Centre. Baumgartner, L.J., Reynoldson, N. and Gilligan, D.M. 2006. ‘Mortality of larval Murray cod (Maccullochella peelii peelii) and golden perch (Macquaria ambigua) associated with passage through two types of low-head weirs’. Marine and Freshwater Research 57: 187–191. Baumgartner, L. J., Reynoldson, N., Cameron, L. and Stanger, J. 2007. The effects of selected irrigation practices on fish of the Murray-Darling Basin. NSW Department of Primary Industries – Fisheries Final Report Series No. 92. NSW Department of Primary Industries, Narrandera Fisheries Centre. Bennett, M. and Green, J. 1993. Preliminary Assessment of Gwydir Wetlands Water Needs. Department of Water Resources Technical Services Division. December 1993. 11 pp. Bennett, M. and McCosker, R.O. 1994. ‘Estimating Environmental Flow Requirements of Wetlands’. Proceedings form the Environmental Flows Seminar, 25–26 August 1994, Canberra. Australian Water and Waste Water Association Incorporated, Artarmon, NSW. pp. 9–16. Braithwaite, L.W., Maher, M., Briggs, S.V. and Parker, B.S. 1986. ‘An Aerial Survey of Three Game Species of Waterfowl (Family Anatidae) Populations in Eastern Australia’. Australian Wildlife Research 13: 213–223. Bryant, C.E. 1934. ‘The Camp-out at Moree, N.S.W. and the Birds Observed’. The Emu Vol XXXIII: 159–173.

Bunn, S. E., Davies, P. M., and Winning, M. 2003. Sources of organic carbon supporting the food web of an arid zone floodplain river. Freshwater Biology 48, 619–635. Copeland, C., Schooneveldt-Reid, E. and Neller, S. 2003. Fish everywhere: an oral history of fish and their habitats in the Gwydir River. NSW Fisheries, Ballina, NSW. Davis, T.L.O. 1977a. ‘Food Habits of the Freshwater catfish, Tandanus tandanus Mitchell, in the Gwydir River, Australia, and Effects Associated with Impoundment of this River by the Copeton Dam’. Australian Journal of Marine and Freshwater Research 28: 455–465. Davis, T.L.O. 1977b. ‘Reproductive Biology of the Freshwater catfish, Tandanus tandanus, Mitchell, in the Gwydir River, Australia II. Gonadal Cycle and Fecundity’. Australian Journal of Marine and Freshwater Research 28:159–169. DEC 2006. Ecological character of the Gwydir Wetlands private Ramsar site in NSW. Final Report August 2006. Report prepared by Biosis Research and Wetlands International Oceania for the NSW Department of Environment and Conservation. DLWC. 1998. Gwydir Environmental Flow Rules 1998/99. NSW Department of Land and Water Conservation: Sydney.

64 Final report on the Gwydir waterbird and fish habitat study

D’Ombrain, E.A. 1921. ‘A Trip to the “Watercourse,” North West N.S.W.’. The Emu Vol XXI: 59– 67. DWR 1993. Water resources of the Gwydir Valley. New South Wales Department of Water Resources. Environment Australia. 2000. Australian Guidelines for Water Quality Monitoring and Reporting (2000). Prepared for the Australian and New Zealand Environment and Conservation Council and the Agriculture and Resource Management Council of Australia and New Zealand. October 2000. Environment Australia, Canberra. Environment Australia. 2001. A Directory of Important Wetlands in Australia. Third Edition. Environment Australia, Canberra. Fletcher, A.R., Morison, A.K. and Hume, D.J. 1985. ‘Effects of carp, Cyprinus carpio L., on Communities of Aquatic Vegetation and Turbidity of Waterbodies in the Lower Goulburn River Basin’. Australian Journal of Marine and Freshwater Research 36: 311–327. Froese, R. and Pauly, D. 2008. FishBase. Electronic publication. www.fishbase.org, version 04/2008. Accessed 15 June 2008. Garnett, S. T. and Crowley, G. M. 2000. The Action Plan for Australian Birds 2000. Environment Australia, Canberra. Gehrke, P.C., and Harris, J.H. 2001. ‘Regional-scale effects of flow regulation on lowland riverine fish communities in New South Wales, Australia’. Regulated Rivers: Research and Management 17: 369–391. Growns, I. and Rodgers, M. 2002. Integrated Monitoring of Environmental Flows 5th Progress Report. Draft. NSW Fisheries Office of Conservation. Harris, J.H. and Gehrke, P.C. 1997. Fish and Rivers in Stress: The NSW Rivers Survey. NSW Fisheries, Cronulla NSW. Heagney, E.C., Fowler, A., Allman, R. and Spencer, J.A. 2009. Growth and condition of juvenile Australian smelt and bony bream in the Gwydir Wetlands: an otolith-based analysis. Final report for the Department of Environment and Climate Change NSW. University of New South Wales, Sydney. Higgins, P. J., and Davies, S. J. J. F. 1996. Handbook of Australian, New Zealand and Antarctic Birds. Oxford University Press, Melbourne. Hope, M. and Bennett, R. 2003. Gwydir Catchment Irrigation Profile. NSW Agriculture, Dubbo. Humphries, P., King, A. J., and Koehn, J. D. 1999. Fish, flows and flood plains: links between freshwater fishes and their environment in the Murray-Darling River system, Australia. Environmental Biology of Fishes 56, 129–151. Johnson, B. 2001. Water for the environment in the Gwydir River: Providing water for the environment from Copeton Dam. NSW National Parks and Wildlife Service. Unpublished report. Johnson, W. 2004. Breeding of colonially nesting waterbirds. Unpublished report. Keyte, P. 1992. Lower Gwydir River Wetland: Preliminary identification of resource management issues. Discussion Paper. Report by Lower Gwydir River Wetland Management Plan Steering Committee. April 1992. Keyte, P.A. 1994. Lower Gwydir River Wetland Plan of Management 1994-1997. Report by NSW Department of Water Resources for the Lower Gwydir River Wetland Steering Committee. Sydney.

Final report on the Gwydir waterbird and fish habitat study 65

King, A.J., Robertson, A.I. and Healey, M.R. 1997. ‘Experimental manipulations of the biomass of introduced carp (Cyprinus carpio) in billabongs. I. Impacts on water-column properties’. Marine and Freshwater Research 48: 435–443. Kingsford, R.T.1999. ‘Aerial survey of waterbirds on wetlands as a measure of river and floodplain health’. Freshwater Biology 41: 425–438. Kingsford, R.T. 2000. ‘Review: Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia’. Austral Ecology 25: 109–127. Kingsford, R.T., Halse, S.A., Porter, J.L. 2008. Aerial surveys of waterbirds – assessing wetland condition. Final report to the National Land & Water Resources Audit. 60pp. University of New South Wales, Sydney. Lake, J.S. 1967. ‘Rearing experiments with five species of Australian freshwater fishes. II. Morphogenesis and Ontogeny’. Australian Journal of Marine and Freshwater Research 18: 155–173. Lane B. A. 1987. Shorebirds in Australia. Nelson, Melbourne. Le Souef, A.S. 1925. ‘Visit to an Egret Rookery’. The Emu Vol XXV: 20. Lintermans, M. 2007. Fishes of the Murray-Darling Basin: An introductory guide. Murray–Darling Basin Commission, Canberra. Llewellyn, L.C. 1973. ‘Spawning, development and temperature tolerance of the Spangled perch, Madigania unicolour (Gunther), from inland waters in Australia’. Australian Journal of Marine and Freshwater Research 24: 73–94. Mahaffey, K. 1985. The Watercourse Country. Moree & District Historical Society. Mallen-Cooper, M. 1993. ‘Habitat changes and declines of freshwater fish in Australia: What is the evidence and do we need more?’ pp. 118–123 in: Hancock, D. (ed.) Australian Society for Fish Biology Workshop on Sustaining Fisheries Through Sustaining Habitat. Australian Government Publishing Service, Canberra. Mallen-Cooper, M. 2000. Review of barriers to fish passage in the Lower Gwydir River floodplain. Fishway Consulting Services. Report to Wetland Care Australia. Marchant, S. and Higgins, P.J. 1990. Handbook of Australian, New Zealand and Antarctic birds. Volume 1: Ratites to Ducks. Oxford University Press: Melbourne. Marchant, S. and Higgins, P.J. 1993. Handbook of Australian, New Zealand and Antarctic birds. Volume 2: Raptors to Lapwings. Oxford University Press: Melbourne. McCosker, R.O. and Duggin, J.A. 1993. Gingham Watercourse Management Plan. Final Report. Department of Ecosystem Management, University of New England, Armidale, NSW. 45 pp. McCosker, R.O. 1994. ‘Capacity Sharing or Catchment Sharing?’ Proceedings form the Environmental Flows Seminar, 25–26 August 1994, Canberra. Australian Water and Waste Water Association Incorporated, Artarmon, NSW. pp. 149–156. McCosker, R.O. 1996. Gwydir Wetlands Ecological Response to Flooding 1995-96. A report prepared for the Gwydir Environmental Flows Committee. LANDMAX, Natural Resource Management Services, Armidale, NSW. McCosker, R.O. 1999a. Gwydir Wetlands Ecological Response to Flooding 1997. A report prepared for the NSW National Parks and Wildlife Service. LANDMAX, Natural Resource Management Services, Armidale, NSW. March 1999. McCosker, R.O. 1999b. Gwydir Wetlands Ecological Response to Flooding 1998. A report prepared for the NSW National Parks and Wildlife Service, NSW Department of Land

66 Final report on the Gwydir waterbird and fish habitat study

and Water Conservation, Gwydir River Management Committee. LANDMAX, Natural Resource Management Services, Armidale, NSW. May 1999. McCosker, R.O. 2001. Gwydir Wetlands Ecological Response to Flooding 2000-2001. A report prepared for the Gwydir Regulated River Committee. LANDMAX: Kangaroo Point, Queensland. May 2001. McGill, A.R. 1944. ‘An Ornithological Trip to North-western New South Wales’. The Emu XLIV: 50–63. MDBC. 2003. Native Fish Strategy for the Murray–Darling Basin 2003–2013. Murray–Darling Basin Ministerial Council. May 2003. 50 pp. Milton, D.A. and Arthington, A.H. 1985. ‘Reproductive Strategy and Growth of the Australian Smelt, Retropinna semoni (Weber) (Pisces: Retropinnidae) and the Olive Perchlet, Ambassia nigripinnis (De Vis) (Pisces: Ambassidae), in Brisbane, South-eastern Queensland’. Australian Journal of Marine and Freshwater Research 36: 329–341. Morrison.M.D. 1998. Choice Modelling, Non-use Values and Benefit Transfer. PhD thesis. University of New South Wales. Morse, F.C. 1918. ‘Nesting Notes from Moree’. The Emu Vol XVIII: 65–71. Morse, F.C. 1922a. ‘Birds of the Moree District’. The Emu Vol XXII: 24–36. Morse, F.C. 1922b. ‘Egret and Glossy Ibis Rookeries’. The Emu Vol XXII: 36–39. Murphy-Fleming, T. and Moles, S. 2003. Individual Property Management Plan for the “Goddard’s Lease” Wetland Ramsar Site. WWF Australia, Canberra. Porter, J.L., Kingsford, R.T. and Hunter, S.J. 2006. Aerial Surveys of Wetland Birds in Eastern Australia - October 2003–2005. Department of Environment and Conservation, NSW. Occasional Paper No. 37. Powell, S.J. 2005. Modelling flood dynamics in a regulated floodplain wetland. Masters Thesis. July 2005. The Australian National University, Canberra. 100 pp. Puckridge, J.T. and Walker, K.F. 1990. ‘Reproductive Biology and Larval Development of a Gizzard Shad, Nematalosa erebi (Gϋnther) (Dorosomatinae: Teleostei), in the River Murray, South Australia’. Australian Journal of Marine Freshwater Research 41: 695– 712. RIS 1999. Ramsar Information Sheet for the Gwydir Wetlands, March 1999. Australian Wetlands Database (accessed 4 June 2008): www.environment.gov.au/water/publications/environmental/wetlands/database/ Reynolds, L.F. 1983. ‘Migration Patterns of Five Fish Species in the Murray–Darling River System’. Australian Journal of Marine and Freshwater Research 34: 857–871. Robertson, A.I., Healey, M.R. and King, A.J. 1997. ‘Experimental manipulations of the biomass of introduced carp (Cyprinus carpio) in billabongs. II. Impacts on benthic properties and processes’. Marine and Freshwater Research 48: 445–454. Roshier, D.A., Robertson, A.I. and Kingsford, R.T. 2002. ‘Responses of waterbirds to flooding in an arid region of Australia and implications for conservation’. Biological Conservation 106: 399–411. Schalk, T. 2006. The Environmental Contingency Allowance history of use in the Gwydir. November 2006. NSW Department of Natural Resources, Armidale. Siebentritt, M.A. 1999. Fish and the Lower Gwydir River Floodplain. Wetland Care Australia, Berri, South Australia.

Final report on the Gwydir waterbird and fish habitat study 67

Spencer, J.A. 2007. Gwydir waterbird and fish habitat study: spring field surveys summary report. NSW Wetland Recovery Program. Rivers and Wetlands Unit, Department of Environment and Climate Change NSW, Sydney. Spencer, J.A. 2008. Gwydir waterbird and fish habitat study: summer field surveys summary report. NSW Wetland Recovery Program. Rivers and Wetlands Unit, Department of Environment and Climate Change NSW, Sydney. Spencer, J.A. 2010. Gwydir waterbird and fish habitat study: final report on historical records of waterbirds and fish populations in the Gwydir Wetlands. NSW Wetland Recovery Program. Rivers and Wetlands Unit, Department of Environment and Climate Change NSW, Sydney. Stuart, I.G. and Jones, M. 2006. ‘Large, regulated forest floodplain is an ideal recruitment zone for non-native common carp (Cyprinus carpio L.)’. Marine and Freshwater Research 57: 333–347. Stuart, I. G., Williams, A., McKenzie, J. and Holt, T. 2006. ‘Managing a Migratory Pest Species: A Selective Trap for Common Carp’. North American Journal of Fisheries Management 26: 888–893. Sullivan, C. 1931. ‘Notes from North-western New South Wales’. The Emu Vol XXXI: 124–135. Wedderburn, S. D., Walker, K.F., Zampatti, B.P. 2008. ‘Salinity may cause fragmentation of hardyhead (Teleostei: Atherinidae) populations in the River Murray’, Australia. Marine and Freshwater Research 59: 254–258. Wilson, G., Bickel, T. O., Berney, P.J. and Sisson, J.L. 2009. Managing environmental flows in an agricultural landscape: the Lower Gwydir floodplain. Third-year report to the Australian Government Department of the Environment, Water, Heritage and Arts. University of New England, Armidale. 67 pp. WRC. 1984. Proposed Water Management Work: Lower Gwydir River. Water Resources Commission. September 1984. Young, W.J. 2001. Rivers as ecological systems: the Murray–Darling Basin. CSIRO Land and Murray–Darling Basin Commission, Canberra. 325 pp.

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Appendix 1: Species names

Waterbird species recorded in the Gwydir Wetlands

Family Common name Scientific name 2007–08

Anatidae Australasian shoveler Anas rhynchotis * F

Australian shelduck Tadorna tadornoides *

Australian wood duck Chenonetta jubata * F

Black swan Cygnus atratus * F

Blue-billed duck Oxyura australis V *

Chestnut teal Anas castanea

Freckled duck Stictonetta naevosa V *

Grey teal Anas gracilis * F

Hardhead Aythya australis * F

Musk duck Biziura lobata * F

Pacific black duck Anas superciliosa * F

Pink-eared duck Malacorhynchus membranaceus * F

Plumed whistling duck Dendrocygna eytoni * F

Wandering whistling duck Dendrocygna arcuata *

Anhingidae Darter Anhinga melanogaster * F

Anseranatidae Magpie goose Anseranas semipalmata V *

Ardeidae Australasian bittern Botaurus poiciloptilus V

Black bittern Ixobrychus flavicollis V

Cattle egret Ardea ibis JC * F

Great egret Ardea alba JC * F

Intermediate egret Ardea intermedia * F

Little bittern Ixobrychus minutus *

Little egret Ardea garzetta * F

Rufous night heron Nycticorax caledonicus * F

White-faced heron Ardea novaehollandiae * F

White-necked heron Ardea pacifica * F

Burhinidae Bush stone-curlew Burhinus grallaarius *

Charadriidae Banded lapwing Vanellus tricolor *

Black-fronted dotterel Elseyornis melanops *

Final report on the Gwydir waterbird and fish habitat study 69

Family Common name Scientific name 2007–08

Double-banded plover Charadrius bicinctus

Inland dotterel Charadrius australis

Masked lapwing Vanellus miles * F

Oriental plover Chardrius veredus JR

Red-capped plover Charadrius ruficapillus

Red-kneed dotterel Erythrogonys cinctus * F

Ciconiidae Black-necked stork Ephippiorhynchus asiaticus E * F

Glareolidae Australian pratincole Stiltia isabella

Gruidae Brolga Grus rubicundus V * F

Jacanidae Comb-crested jacana Irediparra gallinacea V *

Laridae Caspian tern Sterna caspia C F

Common tern Sterna hirundo JCR

Gull-billed tern Sterna nilotica F

Silver gull Larus novaehollandiae F

Whiskered tern Chlidonias hybridus * F

White-winged black tern Chlidonias leucopterus JCR

Pelecanidae Australian pelican Pelecanus conspicillatus F

Phalacrocoracidae Great cormorant Phalacrocorax carbo * F

Little black cormorant Phalacrocorax sulcirostris * F

Little pied cormorant Phalacrocorax melanoleucos * F

Pied cormorant Phalacrocorax varius * F

Plataleidae Australian white ibis Threskiornis molucca * F

Glossy ibis Plegadis falcinellus C * F

Royal spoonbill Platalea regia * F

Straw-necked ibis Threskiornis spinicollis * F

Yellow-billed spoonbill Platalea flavipes * F

Podicipedidae Australasian grebe Tachybaptus novaehollandiae * F

Great-crested grebe Podiceps cristatus * F

Hoary-headed grebe Poliocephalus poliocephalus * F

Rallidae Australian spotted crake Porzana fluminea

Black-tailed native hen Gallinula ventralis * F

Dusky moorhen Gallinula tenebosa * F

Eurasian coot Fulica atra * F

70 Final report on the Gwydir waterbird and fish habitat study

Family Common name Scientific name 2007–08

Purple swamphen Porphyrio porphyrio * F

Spotless crake Porzana tabuensis

Recurvirostridae Banded stilt Cladorhynchus leucocephalus

Black-winged stilt Himantopus himantopus * F

Red-necked avocet Recurvirostra novaehollandiae

Rostratulidae Australian painted snipe Rostratula australis C E *

Scolopacidae Common greenshank Tringa nebularia JCR F

Common sandpiper Actitis hypoleucos JCR

Latham's snipe Gallinago hardwickii JCR F

Little curlew Numenius minutus JCR

Marsh sandpiper Tringa stagnatilis JCR

Ruff Philomachus pugnax JCR

Sharp-tailed sandpiper Calidris acuminata JCR

* Breeding recorded historically. F = species recorded during field surveys 2007–08. Taxonomic nomenclature follows Marchant and Higgins (1990; 1993) and Higgins and Davies (1996). Status: listing under international bird agreements [JAMBA (J), CAMBA (C) and ROKAMBA (R)]. V = listed as vulnerable, E = listed as endangered under TSC Act.

Fish species recorded in the Gwydir River catchment

Status^ Common name Scientific name Distribution NSW National Australian smelt F Retropinna semoni Lower Gwydir

Bony bream F Nematalosa erebi Upper & Lower Gwydir

Darling River hardyhead Craterocephalus amniculus Upper Gwydir

Eastern gambusia F Gambusia holbrooki* Upper & Lower Gwydir

European carp F Cyprinus carpio* Lower Gwydir

Freshwater catfish F Tandanus tandanus Upper & Lower Gwydir

Golden perch F Macquaria ambigua Upper & Lower Gwydir

Goldfish F Carassius auratus* Upper & Lower Gwydir

Lake’s carp gudgeon F Hypseleotris sp.2 Lower Gwydir

Midgeley’s carp gudgeon F Hypseleotris sp.1 Lower Gwydir

Mountain galaxias Galaxius olidus Upper Gwydir

Final report on the Gwydir waterbird and fish habitat study 71

Status^ Common name Scientific name Distribution NSW National Murray cod F Maccullochella peelii peelii Upper & Lower Gwydir V

Murray–Darling rainbowfish F Melanotaenia fluviatilis Lower Gwydir

Olive perchlet Ambassis agassizii Expected E

Redfin perch Perca fluviatilis* Upper Gwydir

River blackfish Gadopsis marmoratus Upper Gwydir

Silver perch Bidyanus bidyanus Upper & Lower Gwydir V

Spangled perch F Leiopotherapon unicolor Lower Gwydir

Unspecked hardyhead F Craterocephalus Lower Gwydir stercusmuscarum fulvus

Western carp gudgeon F Hypseleotris klunzingeri Upper & Lower Gwydir

* Alien species

^ The Lake’s carp gudgeon and Midgley’s carp gudgeon were grouped during field surveys.

F = species recorded during field surveys of the lower Gwydir in 2007–08.

Status: V = vulnerable, E = endangered under TSC Act.

The distribution of each fish species is based on a review of historical data for the Gwydir catchment (see Spencer 2010).

Freshwater turtles and invertebrates recorded during field surveys (2007–08)

Common name Species

Broad-shelled turtle Chelodina expansa

Eastern snake-necked turtle Chelodina longicollis

Freshwater prawns/shrimps Macrobrachium spp.

Yabby (freshwater crayfish) Cherax destructor

72 Final report on the Gwydir waterbird and fish habitat study

Appendix 2: Field site locations (2007–08)

Waterbird ground survey sites

River system Site name* Site^ Latitude Longitude no. Carole Creek Marshalls Pond Lagoon WH1 -29°19.705’ 149°48.127’ Laurella South FS1 -29°21.350’ 149°47.919’ Laurella North FS2 -29°19.996’ 149°47.422’ Sappa CH1 -29°23.867’ 149°52.696’ Sappa Remnant FP1 -29°23.863’ 149°52.740’ Beela North FS3 -29°23.697’ 149°52.168’ Beela South FS4 -29°24.257’ 149°52.852’ Gingham Tyreel Weir CH2 -29°26.123’ 149°46.690’ Talmoi WH2 -29°15.375’ 149°42.356’ Tillaloo WH3 -29°14.975’ 149°29.562’ Baroona WH4 -29°14.394’ 149°28.441’ Crinolyn (Ramsar) FP2 -29°12.981’ 149°07.971’ Jackson FP3 -29°19.352’ 149°32.079’ Bunnor FP4 -29°16.398’ 149°22.694’ Boyanga CH3 -29°12.567’ 149°14.321’ Goddard’s Lease (Ramsar) FP5 -29°15.483’ 149°22.597’ Lower Gwydir Old Dromana Overspill (Ramsar) WH5 -29°20.581’ 149°19.156’ Old Dromana Floodplain (Ramsar) FP6 -29°20.724’ 149°19.276’ Mehi River Mary Brand Park Lagoon CH4 -29°27.802’ 149°50.728’ Whittakers Lagoon WH6 -29°31.573’ 149°39.502’ Combadello Weir CH5 -29°33.408’ 149°39.535’ Telleraga CH6 -29°34.090’ 149°24.362’ Derra CH7 -29°31.736’ 149°16.086’

^ Site types: WH = floodplain waterhole; FS = farm storage; CH = channel; FP = floodplain. * See Figure 4 for site locations.

Final report on the Gwydir waterbird and fish habitat study 73

Fish survey sites

River system Site type Site name Site no. Latitude Longitude

Carole Creek Downstream Sappa CC1 -29°22.917’ 149°50.702’ Carole Creek Downstream Laurella CC2 -29°21.273’ 149°47.761’ Gwydir River Upstream Beela GW2 -29°24.919’ 149°52.078’ Gwydir River Upstream Redmill GW1 -29°25.326’ 149°58.103’ Gingham Downstream Boyanga GH2 -29°12.559’ 149°14.304’ Gingham Downstream Jackson GH1 -29°19.468’ 149°32.143’ Lower Gwydir Downstream Wearmatong LG1 -29°23.819’ 149°32.548’ Lower Gwydir Downstream Allambie LG2 -29°20.588’ 149°25.521’ Mehi River Downstream Derra West MH1 -29°30.779’ 149°14.687’ Mehi River Downstream Telleraga MH2 -29°34.088’ 149°24.361’ Mehi River Upstream Chinook MH3 -29°28.519’ 149°58.645’ Mehi River Floodplain waterhole Whittakers WH1 -29°31.573’ 149°39.502’ Gingham Floodplain waterhole Talmoi WH2 -29°15.375’ 149°32.356’ Gingham Floodplain waterhole Tillaloo WH3 -29°14.975’ 149°29.562’ Gingham Floodplain waterhole Baroona WH4 -29°14.394’ 149°28.441’ Lower Gwydir Floodplain waterhole Old Dromana WH5 -29°20.733’ 149°18.110’

* See Figure 5 for site locations (note that the five floodplain waterholes were mostly dry in October 2007 and were only sampled during surveys in March 2008).

74 Final report on the Gwydir waterbird and fish habitat study

Waterbird aerial survey sites

October 2007

Farm storage near the Lower Gwydir Gingham waterhole, Gingham River Watercourse (GH12)

Flooded areas on Old Dromana Ramsar Combadello Weir (MH40) on the site (LG26), Lower Gwydir River Mehi River channel

Dry floodplain areas on Crinolyn Ramsar Pear Paddock Lagoon (GH11), on the site (GH9) Gingham Watercourse See Figure 3 for site locations. (Credit R. Thomas)

Final report on the Gwydir waterbird and fish habitat study 75

Dry Baroona Waterhole (GH18) on the Tillaloo (GH19) Waterhole on the Gingham Watercourse Gingham Watercourse 8 October 2007. See Figure 3 for site locations. (Credit R. Thomas)

76 Final report on the Gwydir waterbird and fish habitat study

Waterbird ground survey sites

March 2008

Crinolyn Ramsar site (Gingham) Beela farm storage (Carole Creek)

Mary Brand Park Lagoon (Mehi River) Whittakers Lagoon (Mehi River)

Talmoi Waterhole (Gingham) Bunnor (Gingham) (Credit: K. Brennan)

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Jackson (Gingham) Goddard’s Lease Ramsar site (Gingham)

Old Dromana Ramsar site (overspill) Old Dromana Ramsar site (floodplain) (Lower Gwydir River) (Lower Gwydir River)

Marshall’s Pond Lagoon (Carole Creek) Baroona Waterhole (Gingham)

(Credit: K. Brennan)

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Fish sampling sites on the Carole, Gingham and Lower Gwydir River channels

March 2008

Carole Creek: Sappa (CC1) Carole Creek: Laurella (CC2)

Gingham Watercourse: Jackson (GH1) Gingham Watercourse: Boyanga (GH2)

Lower Gwydir River: Wearmatong (LG1) Lower Gwydir River: Allambie (LG2) (Credit: J. Spencer)

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Fish sampling sites on the Mehi and Gwydir River

March 2008

Mehi River: Derra West (MH1) Mehi River: Telleraga (MH2)

Gwydir River: Redmill (GW1) Gwydir River: Beela (GW2)

Mehi River: Chinook (MH3) (Credit: J. Spencer)

80 Final report on the Gwydir waterbird and fish habitat study

Appendix 3. Habitat requirements of selected waterbird species

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Open-water Australasian Common in Poorly known, Small areas of On water, in or Fringing or Aug–Apr Solitary or loose 0.9–1.3 27 1 56 84 foragers grebe seasonal resident eastern deep permanent near vegetation, patches of colonies swamps, dams Australia, open water with near steep banks emergent and semi- dispersive inland tall fringing or logs in water vegetation permanent aquatic vegetation (15–25 cm) wetlands Cattle egret Widespread Partial migrant, Regularly forage Trees or ground Dead or live Sept–Mar Colonies Maintain 31 42 14 87 and common most birds winter away from water vegetation near trees (eucalypts, foraging throughout in south-east on low-lying swamps casuarinas) in habitat NSW Australia and grasslands, or in dense woodland breed in south- shallow open, or beside east QLD and water meadows swamps, rivers north-eastern with low emergent or pools NSW vegetation (3–15 m) Darter Widespread, Dispersive when Prefer permanent Tree trunks, Trees or tall Nov–Apr Solitary or small 0.3 29–33 25–40 20 93 regularly found not breeding, bodies of open branches, stumps bushes growing loose colonies in areas of open sometimes over water, but in or posts for in or over water often with ibis or water and on great distances vegetated roosting and (>3.5 m) cormorants artificial (>2,000 km), wetlands forage perching waterbodies restricted to where aquatic breeding habitat vegetation sparse during summer Great Coastal and Nomadic with Deep permanent Solitary or Trees, bushes or Sept–Jan; Solitary or dense Maintain 29–33 49 28 110 cormorant permanent wide dispersal waterbodies and communal on tree reeds in or near Mar–Aug colonies foraging inland waters following dams trunks, branches, water (>2 m) habitat successful inland posts or islands breeding near water used for perching

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Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Open-water Great egret Common Dispersive, some Prefer permanent In trees in or near Trees (eucalypt, Sept – early Colonies, often Maintain ND 42 3–16 >98 foragers throughout regular seasonal waterbodies on wetlands casuarinas) May with other foraging (however, (continued) NSW, common movements, floodplains, semi- standing in water egrets, herons, habitat based on on artificial possibly migratory permanent (>7–15 m) spoonbills and other egret waterbodies, swamps with tall cormorants species most breeding emergent estimated to in MDB vegetation, be c. 30 days) sewage farms, channels and large farm dams Great-crested Common Local movements Prefer large open Open water, Inland lakes and Nov–Feb Loose colonies 1–2 28–36 2 ND ND grebe throughout between non- bodies of water, among surface large or solitary NSW, breeding winter with fringing vegetation or well- waterbodies, in especially on flocks and more vegetation floodd cover flooded weeds, artificial dispersed (Typha), shrubs or reeds, drooping impoundments breeding sites trees branches of trees Hoary-headed Common Poorly known, Prefer large open Grassy banks, Scattered Oct–Jan Colonies Insufficient 24–28 1 ND ND grebe throughout highly dispersive waterbodies but lignum, flooded sedges, reeds or data NSW, in drier parts of also found in trees or shrubs lignum (<5 mm) especially on range small waterbodies artificial after flooding with impoundments submerged vegetation Intermediate Widespread in Poorly known, Prefer to forage in Trees fringing Tree canopy Oct–Apr Dense, often Maintain >26 37––53 21 100 egret NSW mainly sedentary fresh water (<80 wetlands and farm (eucalypts) mixed colonies foraging but possibly mm deep), among storages standing in or with egrets, ibis, habitat migratory dense aquatic and near water spoonbills and emergent (>1.5–15 m) herons vegetation Little black Generally Dispersive, large Mainly open water Trees, stumps, Canopy of trees Insufficient Colonies with Maintain ND ND ND ND cormorant widespread movements after (>1 m) to allow posts, banks of in water (up to data, other cormorant foraging except in drought follows cooperative channels and 30 m) generally species, herons, habitat central west wet period inland feeding in large artificial structures spring– darter, ibis and and south-west lakes, artificial summer, darters, impoundments continuous in occasionally and swamps with favourable solitary open water conditions

82 Final report on the Gwydir waterbird and fish habitat study

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Open-water Little egret Widespread, Poorly Prefer shallow Trees, banks and In tree canopy Oct–Mar Solitary or mixed Maintain 20–25 32–46 ND >71 foragers but restricted understood, open water (0.1– artificial structures near wetlands, colonies, with foraging (continued) breeding sites nomadic and 0.5 m), but can often in standing ibis, egrets, habitat in coastal and some seasonal forage in deep water (3–7 m) herons and inland areas migration water and aquatic spoonbills vegetation Little pied Widespread Dispersive, Open water in Trees, stumps, Trees Insufficient Colonies with Maintain ND ND ND ND cormorant except in possibly migratory natural and rocks, earth banks (eucalypts, data, probably other foraging central west artificial wetlands, and artificial casuarinas) or continuous cormorants, ibis, habitat shallow margins structures bushes (lignum) herons and of lakes, pools in or near water spoonbills with wooded (>2.8 m) edges and semi- permanent swamps Rufous night Throughout Poorly Mainly nocturnal, Communal roosts, High parts of Spring– Large colonies, Maintain 23–24 42–49 ND >73 heron NSW, but most understood, soft substrate in dense cover in tree in dense summer often mixed with foraging common in generally wetlands, or slow leafy trees close to trees and shrubs other herons, habitat MDB, prefer nomadic, at least waterbodies with water, also in (1–20 m) egrets, ibis and permanent in winter, tall vegetation lignum and reed spoonbills waterholes sedentary in beds inland favourable habitat Pied Widespread in Largely sedentary, Large sheets of Islands, fringing or Live and dead Insufficient Colonies, with Maintain 35 47–60 80 175 cormorant NSW some juvenile open water, projecting tree trees (0.5–3.0 m) data, probably other cormorant foraging dispersal permanent lakes trunks, branches continuous species and habitat and dams and posts spoonbills White-faced Widespread in Poorly Prefer waterholes, Trees beside In wetlands with Aug–Mar Usually solitary, Maintain 24–26 46 18 90 heron NSW understood, floodplains, wetlands, fringing/flooded occasionally in foraging locally nomadic, freshwater communal or trees (2–25 m) mixed-species habitat congregate on meadows, tall solitary colonies remaining emergent wetlands during vegetation, drought regularly use farm dams

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Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Open-water White-necked Widespread, Disperse, irruptive Shallow Live or dead trees, In wetlands with Early Aug– Loose colonies Maintain 28–30 42–49 ND >79 foragers heron thought to be following floodwater (<70 usually solitary flooded or early Feb with other foraging (continued) more common availability of mm), artificial fringing trees, species, habitat inland ephemeral waterbodies, wet often in dead occasional wetlands grasslands, trees or living solitary aquatic vegetation eucalypts or casuarinas (1–40 m) Deep-water Black swan Common in Adults sedentary Terrestrial and Nest used for Emergent Continuous Solitary on small 0.3–0.6 45 1 150–170 >216 foragers southern and in permanent aquatic, shallow resting vegetation when waterbodies, eastern NSW wetlands, young or deep open (cumbungi), conditions large colonies and adults from water with flooded stumps, suitable on larger ephemeral submerged floating masses waterbodies habitats move far aquatic plants and of debris, bases and often emergent of trees in vegetation flooded woodlands (0.3 m) Blue-billed Widespread, Short-distance Deep permanent Solitary or Tall vegetation Generally Solitary Insufficient 29–31 1 56 88 duck mostly southern movements waterbodies communal, usually (cumbungi, Sept–Feb data MDB between breeding on open water lignum, spike and overwintering rush) over deep sites, long water distance dispersal (15–30 cm) in exceptional years Musk duck Widespread, Adults sedentary Deep permanent Not known, Tall, thick Sept–May Solitary 0.4–1.4 27 1 ND ND mostly MDB on permanent waterbodies probably on open vegetation waterbodies, water and nest (cumbungi, dispersive on during breeding reeds, rushes, ephemeral season lignum), wetlands occasionally clump of grass (0.25 m)

84 Final report on the Gwydir waterbird and fish habitat study

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Dabbling Australasian Widespread, Dispersive but Open water, soft Open water, banks Ground, open Aug–Nov Solitary Nest away 30–35 1 56–70 106 ducks shoveler most common poorly known, mud in fertile or low or other low paddocks or low from water in south-west relatively wetlands, prefer perches embankments, (100–200m) NSW, which is sedentary large deep close to water in breeding permanent lakes low-level stronghold and swamps vegetation (tussocks, reeds) Freckled duck Widespread, Dispersive from Shallow Banks, posts, Lignum, Jun–Dec Solitary Insufficient 33 1 63 97 mostly north- breeding sites in productive waters snags, sometimes re- data western NSW western NSW, or soft mud at occasionally on use old nests and MDB sedentary in wet wetland edges, open water from ibis and years, disperse densely vegetated swans widely in dry years swamps (15–60 cm) Grey teal Widespread Highly dispersive Terrestial Communal roosts Tree hollows in Jun–Feb Solitary Insufficient 31–37 1 46–64 102 from breeding wetlands, farm on logs, stumps large trees (river data sites, respond to dams, shallow and fallen red gum, black climatic changes open water (<1 m) branches or box) (3.5 m), with movements or flooded shoreline long grass, over large marginal lignum distances vegetation, occasionally deep water Pacific black Widespread Dispersive from Terrestrial Low perches on Hollows in trees Seasonal, Solitary Insufficient 36–42 1 52–66 108 duck inland areas in wetlands, shallow fallen timber, tree (river red gum), insufficient data summer, largely or deep waters, branches and disused nests data sedentary on often among posts permanent water aquatic vegetation, farm dams Pink-eared Widespread, Highly dispersive Terrestrial Edge of water, low Hollows, tops of Continuous Solitary 0.39–1.62 33 1 ND ND duck most common from inland, wetlands, open branches above logs and stumps when in MDB responding to water and soft water, open water (1–5 m) conditions water availability mud, prefer suitable shallow turbid water Grazing Australian Most common Migratory between Grasslands, Insufficient data Hollow live or Jul–Nov Solitary Insufficient 41 2 70 113 waterfowl shelduck in southern breeding and croplands and dead trees, or on data NSW moulting sites terrestrial ground (>1,000 km) wetlands, large open waterbodies

Final report on the Gwydir waterbird and fish habitat study 85

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Grazing Australian Widespread Highly dispersive Grasslands, Near water, banks Tree hollows, Jul–Dec Solitary Insufficient 38–44 1 71 116 waterfowl wood duck in ephemeral woodlands and and pasture, usually live in or data (continued) habitats, localised terrestrial sometimes perch near water movements in wetlands, shallow in trees favourable edges of wetlands conditions and farm dams Magpie goose Restricted, most Seasonal Floodplain Nocturnal Tall vegetation Aug–Mar Exclusive 0.3–0.8 35 1 141 177 common in movements, wetlands, deep communal roosts (cumbungi, colonies, central and based on food and waterbodies in dry in trees lignum) over occasionally north-eastern water availability season, (eucalyptus), deep water solitary NSW grasslands during the day (1.2 m) roost on dry banks near water or on water in deep wetlands Plumed Generally Migratory from Open grasslands, Open banks near On high ground Nov–Apr Solitary Nest away 40 ND ND ND whistling duck widespread permanent water shallow edges of waterbodies in grassland from water flocking sites to wetlands vegetation, (>1 km) widely dispersed under bushes or breeding sites in sapling trees wet season away from wetland Large Australian Generally Adults sedentary Shallow water and Trees, usually near Large branches Sept–Apr Solitary/mixed Insufficient 22–25 30 >22 77 wading birds white ibis widespread in south-eastern soft substrate water of trees (up to colonies with data except in Australia, partial margins of 30 m), or other ibis, central west migrants in south- waterbodies, wide flattened reeds, herons, and south-west western Australia, range of wetland lignum, rushes spoonbills and immatures types and cumbungi egrets dispersive, wetland dependent Black-necked Most common Largely sedentary, Open, semi- Edge of wetlands, Tall live or dead Insufficient Solitary Maintain ND 100–115 ND ND stork in north-eastern some immatures permanent rarely in trees trees, generally data foraging NSW, move large swamps with tall in or near habitat occasional distances vegetation, freshwater records south of shallow water swamps but can Sydney over grassland, be found in open freshwater paddocks meadows, small (>20 m) farm dams

86 Final report on the Gwydir waterbird and fish habitat study

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Large Brolga Along major Partly migratory, Terrestrial Nocturnal Shallow July–Mar Solitary 0.3–0.4 32–35 1–2 330 352 wading birds river systems in some dispersive wetlands, communal roosts, wetlands with (continued) north-west and movements,in grasslands and usually in shallow scattered trees, Riverina south-eastern woodlands, water among tussock Australia regularly cultivated grasses and move between paddocks and sedges, mounds breeding and non- impoundments above water breeding sites Glossy ibis Widespread but Migratory, Shallow water and Dead/living trees Flattened lignum Oct–Feb Solitary/mixed Insufficient ND 25 >14 >64 prefer inland breeding in south soft substrate often in or near or small trees colonies with data (however, ephemeral/ in summer and margins of water (0.1–0.5 m) other ibis, based on permanent wintering in waterbodies herons, other ibis wetlands northern Australia spoonbills and species egrets estimated to be c. 25 days) Royal Widespread, Sedentary in Permanent and Trees near feeding Tree canopy Oct–Mar Solitary/loose 0.5–1.5 20–25 ND ND ND spoonbill perhaps more coastal habitats, ephemeral or nesting sites, or (eucalypts) (1– colonies with common on some movements wetlands, wet banks near water 15 m), reeds, egrets, herons coast inland grasslands, lignum and and ibis, some shallow water rushes (0.5– site fidelity (<0.4 m), sewage 1.5 m), usually treatment works over water Straw-necked Generally Partial migrant, Grasslands, Communal, tall Flattened reeds, Spring– Solitary, or 1.0 c.25 28 14 67 ibis widespread, locally sedentary cultivated land, or trees, mainly lignum and summer mixed colonies, NSW is near breeding in aquatic nocturnal, but also cumbungi, trees usually with stronghold for sites, regular shallows (<0.25 rest near wetlands very occasionally other ibis breeding movements m) of permanent/ during day species, herons, between coast ephemeral spoonbills and and inland wetlands egrets breeding sites Yellow-billed Most common Poorly known, Forage in shallow Trees in or near Trees (river red Sept–Apr Solitary, or semi- Maintain 26–31 35 >14 80 spoonbill in inland NSW, some seasonal water (<0.4 m) in open water gums) (2–8 m), colonial, foraging breeding movements in terrestrial lignum or reeds sometimes habitat stronghold in response to inland wetlands, flooded associated with southern NSW rainfall grasslands, mixed colonies wetlands with of ibis, egrets, sparse or low cormorants and vegetation herons, some site fidelity

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Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Small Black-fronted Widespread Poorly known, Muddy margins of Muddy edges of Depression in Aug–Apr Solitary, site Nest away 29–34 1–2 49–57 93 waders dotterel mainly sedentary small waterbodies wetlands ground, often on faithful from water and artificial banks of sand, (29 m) habitats gravel, pebbles usually near water edge Black-winged Widespread Dispersive in Prefer shallow, Shallow water or Depression in Aug–Dec Colonies, Insufficient 27–30 1 28–34 65 stilt response to open wetlands banks in sheltered ground, or loose occasionally data rainfall and with short wetlands platform or solitary wetland emergent mound availability vegetation or wet (7–16 cm) mud Comb-crested Most common Dispersive in Deep permanent Nocturnal roosting Floating or Sept–Apr Solitary Insufficient 32 ND >65 ND jacana in north-eastern response to wetlands and in extra nests emergent data NSW wetland swamps, with vegetation availability aquatic vegetation, margins of wetlands Red-kneed Widespread, Dispersive in Exposed margins Shoreline or in Depression in Aug–Mar Solitary, small Insufficient ND 2 ND ND dotterel breed in MDB response to or shallow water vegetation ground on colonies data rainfall and (1–1.5 cm) of margins of wetland temporary and wetlands, dense availability permanent shrubs (lignum wetlands and grasses) (5 cm) Shoreline Black-tailed Widespread in Dispersive and Permanent and Nocturnal in long Near water, in Aug–Dec Solitary, small Insufficient 24–25 ND ND ND foragers native hen inland NSW highly irruptive, ephemeral grass and dense dense vegetation colonies data regular seasonal wetlands, farm vegetation, roost at (lignum, movements dams base of trees in saltbushes) day (0.3–0.8 m) Dusky Widespread, Poorly known, Permanent or Reed beds, fallen Ground or over Aug–Mar Cooperative Insufficient 36 3–4 28 68 moorhen but few records sedentary or ephemeral logs or stumps, water in fringing breeders in data from western dispersive, partly wetlands, open trees at wetland vegetation small groups NSW migratory water with fringing margin (reeds, rushes, and aquatic lignum, willows) vegetation, farm at wetland dams margin (1.8 m)

88 Final report on the Gwydir waterbird and fish habitat study

Functional Species Distribution in Movements Foraging habitat Roosting/ Nesting habitat Breeding Social Flooding Breeding duration (days)^ group* NSW perching habitat (nest height) season organisation depth (m) Laying and Nestling Post– Est. incubation period fledging total dependency time Shoreline Eurasian coot Throughout Dispersive, no Shallow, Nocturnal roosts in Floating or Aug–Feb Solitary, small Insufficient 38–41 23 35 99 foragers NSW large-scale permanent or emergent dense emergent colonies data (continued) seasonal ephemeral vegetation, open vegetation, movements wetlands with high water, grassy shrubs and trees diversity of margins of (25–275 cm) submerged and wetlands, mats of emergent aquatic floating vegetation, vegetation perch on trees, shrubs and rocks Purple Throughout, Some dispersive Wetlands and Perch in tree Reeds, isolated Aug–Dec Solitary, Insufficient 28–30 3 60 93 swamphen most common movements, move adjacent open canopy, nocturnal tussocks, communal data in east to inland to breed grasslands, with roosting on croplands, fallen breeding during floods fringing aquatic platforms in reeds logs (0–80 cm) vegetation

Sources: Marchant and Higgins (1990; 1993). *Functional groups adapted from Roshier et al. (2002). ^Total breeding duration (in days) relates to the time from commencement of nest building, through laying, incubation and hatching, the nestling period and extra care provided during the post-fledging period. Where the total time is stated, this figure only represents an estimate of the minimum time required for the successful completion of breeding. Most species also require a lag period before the commencement of laying and incubation in order to pair up and build up fat reserves before breeding commences. Note that limited information was available for the time required for nest building and egg laying for many species (ND = not determined). Note that information was only reviewed for 42 waterbird species which have been recorded breeding in the Gwydir Wetlands, but a further eight waterbird species have also historically bred in the Gwydir Wetlands including; hardhead, masked lapwing, whiskered tern, Australian painted snipe, banded lapwing, bush stone curlew, little bittern and wandering whistling duck (see Appendix 1).

Final report on the Gwydir waterbird and fish habitat study 89 www.environment.nsw.gov.au