Consultation Document on Listing Eligibility and Conservation Actions

Bidyanus bidyanus (Silver Perch)

You are invited to provide your views and supporting reasons related to:

1) the eligibility of Bidyanus bidyanus (Silver Perch) for inclusion on the EPBC Act threatened species list in the Endangered category; and

2) the necessary conservation actions for the above species.

Evidence provided by experts, stakeholders and the general public are welcome. Responses can be provided by any interested person.

Anyone may nominate a native species, ecological community or threatening process for listing under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) or for a transfer of an item already on the list to a new listing category. The Threatened Species Scientific Committee (the Committee) undertakes the assessment of species to determine eligibility for inclusion in the list of threatened species and provides its recommendation to the Australian Government Minister for the Environment and Energy.

Responses are to be provided in writing either by email to: [email protected] or by mail to:

The Director Marine and Freshwater Species Conservation Section Biodiversity Conservation Division Department of Agriculture, Water and the Environment PO Box 858 Canberra ACT 2601

Responses are required to be submitted by 12 March 2021. Contents of this information package Page General background information about listing threatened species 2 Information about this consultation process 3 Draft information about the common name and its eligibility for listing 4 Conservation actions for the species 24 References cited 26 Collective list of questions – your views 34

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General background information about listing threatened species The Australian Government helps protect species at risk of extinction by listing them as threatened under Part 13 of the EPBC Act. Once listed under the EPBC Act, the species becomes a Matter of National Environmental Significance (MNES) and must be protected from significant impacts through the assessment and approval provisions of the EPBC Act. More information about threatened species is available on the department’s website at: http://www.environment.gov.au/biodiversity/threatened/index.html.

Public nominations to list threatened species under the EPBC Act are received annually by the department. In order to determine if a species is eligible for listing as threatened under the EPBC Act, the Threatened Species Scientific Committee (the Committee) undertakes a rigorous scientific assessment of its status to determine if the species is eligible for listing against a set of criteria. These criteria are available on the Department’s website at: http://www.environment.gov.au/system/files/pages/d72dfd1a-f0d8-4699-8d43- 5d95bbb02428/files/tssc-guidelines-assessing-species-2018.pdf.

As part of the assessment process, the Committee consults with the public and stakeholders to obtain specific details about the species, as well as advice on what conservation actions might be appropriate. Information provided through the consultation process is considered by the Committee in its assessment. The Committee provides its advice on the assessment (together with comments received) to the Minister regarding the eligibility of the species for listing under a particular category and what conservation actions might be appropriate. The Minister decides to add, or not to add, the species to the list of threatened species under the EPBC Act. More detailed information about the listing process is at: http://www.environment.gov.au/biodiversity/threatened/nominations.html.

To promote the recovery of listed threatened species and ecological communities, conservation advices and where required, recovery plans are made or adopted in accordance with Part 13 of the EPBC Act. Conservation advices provide guidance at the time of listing on known threats and priority recovery actions that can be undertaken at a local and regional level. Recovery plans describe key threats and identify specific recovery actions that can be undertaken to enable recovery activities to occur within a planned and logical national framework. Information about recovery plans is available on the department’s website at: http://www.environment.gov.au/biodiversity/threatened/recovery.html.

Privacy notice The Department will collect, use, store and disclose the personal information you provide in a manner consistent with the Department’s obligations under the Privacy Act 1988 (Cth) and the Department’s Privacy Policy.

Any personal information that you provide within, or in addition to, your comments in the threatened species assessment process may be used by the Department for the purposes of its functions relating to threatened species assessments, including contacting you if we have any questions about your comments in the future.

Further, the Commonwealth, State and Territory governments have agreed to share threatened species assessment documentation (including comments) to ensure that all States and Territories have access to the same documentation when making a decision on the status of a potentially threatened species. This is also known as the ‘common assessment method’. As a result, any personal information that you have provided in connection with your comments may be shared between Commonwealth, State or Territory government entities to assist with their assessment processes.

The Department’s Privacy Policy contains details about how respondents may access and make corrections to personal information that the Department holds about the respondent, how respondents may make a complaint about a breach of an Australian Privacy Principle, and how

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the Department will deal with that complaint. A copy of the Department’s Privacy Policy is available at: http://environment.gov.au/privacy-policy .

Information about this consultation process Responses to this consultation can be provided electronically or in hard copy to the contact addresses provided on Page 1. All responses received will be provided in full to the Committee and then to the Australian Government Minister for the Environment.

In providing comments, please provide references to published data where possible. Should the Committee use the information you provide in formulating its advice, the information will be attributed to you and referenced as a ‘personal communication’ unless you provide references or otherwise attribute this information (please specify if your organisation requires that this information is attributed to your organisation instead of yourself). The final advice by the Committee will be published on the department’s website following the listing decision by the Minister.

Information provided through consultation may be subject to freedom of information legislation and court processes. It is also important to note that under the EPBC Act, the deliberations and recommendations of the Committee are confidential until the Minister has made a final decision on the nomination, unless otherwise determined by the Minister.

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Bidyanus bidyanus

Silver Perch

Taxonomy

Conventionally accepted as Bidyanus bidyanus (Mitchell 1838).

Species Information

Other Names

Black Bream, Silver Bream, Bream, Bidyan, Tcheri, Grunter.

Indigenous Names and Cultural Significance

Fish name in italics, likely Indigenous language group in brackets – Bidyan (Yuwaalaraay and/or Gamilaraay), Tooroo (Morunde), Teheree (Ngarrindjeri), Kooberry (Wiradjuri), Kupé (Ngunnawal), Bagguck, Karpa, Buruitjall, Bipe (all Jari Jari) (sources: Bennett 1834, Trueman 2011).

Sir Thomas Mitchell (aka Major Mitchell) recorded Silver Perch being referred to as Bidyan by the local Indigenous people (likely Yuwaalaraay or Gamilaraay people) in the Barwon River region (Mitchell 1838).

Description

The Silver Perch is a medium sized, deep-bodied, laterally compressed fish. It can reach lengths up to 61 cm and weights up to 8 kg (Mitchell 1838; Pollard et al., 1980; Merrick 1996; Allen et al., 2002; Lintermans 2007) though is typically 30-40 cm in length and up to 1.5 kg in weight (Mallen-Cooper & Stuart 2003). It is very similar, almost undistinguishable, to the only other described Bidyanus species – Bidyanus welchi (Welch’s Grunter), except the Silver Perch has a higher number of lateral line scales (Allen et al., 2002). Compared to other commonly referred to large ‘perch’ species of the Murray-Darling system, Macquaria ambigua (Golden Perch) and Macquaria australasica (Macquarie Perch), the Silver Perch has much smaller scales (Lintermans 2007). These other ‘perch’ species are members of the Percichthyidae family, whereas the Silver Perch is a member of the Terapontidae family, of which many of its species inhabit northern Australian freshwater systems and are commonly referred to as ‘grunter’ given the habit to emit an audible grunting sound when alarmed or stressed (e.g. during capture).

Silver Perch have a relatively small head and mouth, compared to other fish species of similar size (Merrick 1996; Allen et al., 2002; Lintermans 2007). The body ranges in colour from silvery- grey to olive-greenish to brown on the back to a lighter, sometimes whitish, belly (Merrick 1996; Allen et al., 2002; Lintermans 2007). Fins are dusky grey in colour and the tail is slightly forked (Merrick 1996; Allen et al., 2002; Lintermans 2007).

Distribution

Summary

The Silver Perch is endemic to the waters of the Murray-Darling Basin (Merrick 1996; Allen et al., 2002; Lintermans 2007). The species was once widespread and ubiquitous throughout most of the Murray-Darling Basin, common from the Lower Lakes at the Murray Mouth in South Australia to at least the slopes zone (200-400 m a.s.l.) of all major river valleys (Trueman 2011).

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In New South Wales and Queensland, the species was common in upland zones (400-700 m a.s.l.) and there are records of the species occurring in the montane zone (>700 m a.s.l.), especially in the Murrumbidgee River catchment (Trueman 2011). In Victoria, the species was rarely recorded in upland and montane zones of waterways (Trueman 2011). The species’ abundance in any given area, especially in upland and montane zones, was likely to be highly dependent on migrations of the species up- and downstream in waterways and connected tributaries (Pratt 1979; Trueman 2011). Observations in the upper Murrumbidgee River catchment tend to suggest a migration which occurred in spring and summer from deeper sections of downstream areas to upstream parts of the catchment (Pratt 1979). The migration downstream was reported to occur at the end of summer (Pratt 1979).

The very similar Silver Perch and Welch’s Grunter do not naturally co-inhabit the same waterways. The Silver Perch is naturally restricted to the Murray-Darling Basin, whereas the Welch’s Grunter is restricted to the Lake Eyre Drainage rivers and the Bulloo River (which is isolated from both the Lake Eyre Drainage and Murray-Darling Basin catchments) (Allen et al., 2002).

Historical distribution

The Silver Perch once had a widespread distribution throughout the Murray-Darling Basin and persisted in most locations until the 1950s following European settlement. The species remained relatively common in the Paroo River catchment in far west New South Wales and Queensland until the late-1980s (Gehrke et al., 1995; 1999; NSW DPI 2006). Within the Warrego and Balonne river catchments in Queensland, the species was once present in strong populations in the late-1800s/early-1900s (The Queenslander 1867; Catholic Press 1920; Longreach Leader 1944). Similarly, the species was also once very common in the waterways which make up the “Border Rivers” (Armidale Express 1874; The Critic 1904; Freeman’s Journal 1906; Warwick Daily News 1937; Balonne Beacon 1940) and the Gwydir, Namoi and Castlereagh river catchments in northern New South Wales (Sydney Mail 1904; Daily Observer 1917; AWW 1962).

Further south in New South Wales, the Silver Perch was once very common in the Bogan and Macquarie river catchments until at least the 1950s (SHM 1859; Evening News 1870; BFP 1890; DD&WI 1899; Nepean Times 1936; DL&MA 1950). The species was so common in the Lachlan River it is commercially harvested in the late-1800s (GH&C 1867; Sydney Mail 1874). Large catches were still being reported from Lake Burrinjuck on the Murrumbidgee River up until the mid-1980s (Canberra Times 1972; 1985) and the species has not been recorded in the ACT section of the Murrumbidgee River since 1988 (ACT Government 2018). Monitoring at two sites in Burrinjuck Reservoir in 2004 failed to locate any specimens (Gilligan 2005).

In Victoria, the species once occurred throughout most of the major river valley tributaries of the Murray River. The species was common in the Mitta Mitta, lower Kiewa, Ovens, Goulburn- Broken, Campaspe, Loddon river catchments in the late-1800s/early-1900s (O&M Advertiser 1882; 1883; The Australasian 1873; Bendigo Advertiser 1879; Leader 1886; The Argus 1908a; 1908b; Yackandandah Times 1917; The Age 1920; Advocate 1932)

In South Australia, Silver Perch were very common in Lake Alexandrina with reports of massive recreational hauls up until the 1950s (MDC 1952) and in the Lower Murray River in the early- 1900s (The Telegraph 1921).

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Current distribution

Current natural, wild, and self-sustaining populations of the Silver Perch have contracted from the majority of the Murray-Darling Basin, down to a region centred on the middle-Murray River. In the Murray River, a healthy, self-sustaining population of Silver Perch occurs from Mulwala Weir downstream to the South Australian border, including the Murray River anabranches of the Edward/Wakool system. The population now also extends into the Lower Murray in South Australia from the South Australian border to Lock 1 at Blanchetown, in comparatively very low numbers to historical reports (Zampatti et al., 2018). The species was considered to occur in the the Lower Darling River, from its junction with the Murray River to Menindee Lakes, however the continued existence of this population is unlikely given the impacts of fish kill events during the 2018/19 summer. Recent recordings of the Silver Perch in the lower Goulburn and Ovens rivers in Victoria suggest wild, self-sustaining populations may be re-establishing there. Another self- sustaining population exists outside its natural range in Cataract Reservoir in the Hawkesbury- Nepean catchment that is likely derived from a historical translocation.

Stocked populations supplemented by releases of hatchery-bred fingerlings occur in several reservoirs and a few rivers across southeastern Australia for the purpose of recreational fishing. In Queensland, hatchery-bred fingerlings are released into a number of man-made impounded water bodies including Lake Barambah (Barker/Burnett), Lake Boondooma (Boyle/Burnett), Lake Borumba (Yabba/Mary), Cania Reservoir (Three Moon/Burnett), Connolly Reservoir (Rosenthal/Condamine), Lake Coolmunda (MacIntyre/Dumaresq), Lake Dyer (Brisbane), Lake Leslie (Sandy/Condamine), Lake Maroon (Logan), Lake Moogerah (Reynolds/Brisbane), Lake Somerset (Brisbane) and waterways like Dogwood Creek (Balonne River catchment), Oakey Creek (Condamine) and the Condamine River itself.

In New South Wales, hatchery-bred fingerlings are released into a number of man-made impounded water bodies including Ben Chifley Reservoir (Campbells/Macquarie), Blowering Reservoir (Tumut/Murrumbidgee), Lake Burrendong (Macquarie), Lake Burrinjuck (Murrumbidgee), Lake Chaffey (Peel), Lake Copeton (Gwydir), Googong Reservoir (Queanbeyan/Murrumbidgee), Lake Keepit (Namoi), Split Rock Reservoir (Manilla/Namoi), Lake Windamere (Cudgegong/Macquarie), Lake Wyangala (Lachlan), Lake Glenbawn (Hunter), Lake St Clair (Glennies/Hunter) and rivers such as the Namoi River.

In Victoria, hatchery-bred fingerlings are released into a number of man-made impounded water bodies including Crusoe Reservoir (Coliban), Forest Lake (Coliban), Horseshoe Lagoon (Murray), Kings Billabong (Murray), Lake Lascelles (at Hopetoun), Melton Reservoir (Werribee), Neanger Lake (Coliban), Ouyen Lake (at Ouyen), Tchum Lakes (near Birchup), Taylors Lakes (Maribyrnong), Lake Victoria (Goulburn) and into the Wimmera River itself.

The success rate of released fingerlings in forming stocked populations is generally low, from being present in low numbers, to not being detectable at all. Despite many decades of impoundment stocking, no evidence of successful spawning and recruitment has been recovered from stocked impoundment populations and they show no indication of becoming self-sustaining populations. It suspected that all these populations would become extinct over time if stocking was ceased, and thus do not contribute to the species’ survival in the wild. The only exception to this is Cataract Reservoir, where it does appear that there is a self-sustaining population of Silver Perch derived from a historical translocation.

Self-sustaining populations of Silver Perch no longer occur in the following Murray-Darling Basin major river catchment valleys, where they once did: Paroo (Qld/NSW), Warrego (Qld/NSW), Balonne/Condamine (Qld/NSW), Moonie (Qld), Dumaresq/MacIntyre (Qld/NSW), Gwydir

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(NSW), Namoi (NSW), Castlereagh (NSW), Macquarie (NSW), Bogan (NSW), Lachlan (NSW), Murrumbidgee (NSW/ACT), Mitta Mitta (Vic), Kiewa (Vic), Loddon (Vic).

Figure 1 below provides a diagrammatic representation of the historical distribution of the Silver Perch in southeastern Australia, known current self-sustaining populations and translocated/stocked populations.

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4

6 2

7 5 1 8 3

9 10 11

12 13 14

15

21

16

17

18 20 19

*Selected river catchments: 1. Paroo 2. Warrego 3. Culgoa 4. Maranoa 5. Balonne 6. Condamine 7. Moonie 8. Dumaresq 9. MacIntyre 10. Gwydir 11. Namoi 12. Castlereagh 13. Macquarie 14. Bogan 15. Lachlan 16. Murrumbidgee 17. Upper Murray 18. Mitta Mitta 19. Goulburn 20. Loddon 21. Lower Murray

Figure 1: Current and historical distribution of Silver Perch (Bidyanus bidyanus) in southeastern Australia.

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Relevant Biology/Ecology

The Silver Perch is typically an incredibly hardy, widely tolerant, native fish species (Rowland & Allan 1994). The species can withstand a wide range of environmental conditions and can survive in water temperatures between 2–37°C, albeit only for a few hours at the extreme ends of that range (Lake 1978). The species tends to form large schools and is often observed near the surface in clear water (Lake 1978).

Silver Perch spawn in the spring and summer months between October and February (Clunie & Koehn 2001b), with measurements of egg densities suggesting that peak spawning occurs at night between 9pm and 1am (Tonkin et al., 2007). Eggs have a propensity to drift in higher densities near shore and at the bottom of the water column (Tonkin et al., 2007). Spawning generally occurs following an upstream migration of large schools, and a rise in water level and temperature (Merrick 1996; Clunie & Koehn 2001b). Hatching occurs rapidly after fertilisation, in under 36 hours (NSW DPI 2006). The larvae are relatively small upon hatching in comparison to other native species such as the Macquarie Perch (Macquaria australasica), averaging at approximately 3.6 mm in length (Lake 1967b). Silver Perch eggs and newly developed larvae disperse using downstream drift in river and stream currents (King et al., 2005; Koehn & Harrington 2005).

A Silver Perch individual recorded from the translocated population at Cataract Reservoir was aged at 27 years (440 mm long individual, 1.2 kg in weight) (Mallen-Cooper & Stuart 2003) demonstrating the potential maximum age for the species. However, the oldest specimen aged from the natural riverine population in the Murray River was 17 years (424 mm long individual) (Mallen-Cooper & Stuart 2003). Age at first sexual maturity varies between sexes; males at three years and females at five years. Growth slows dramatically in both sexes immediately before sexual maturity (Merrick 1996; Mallen-Cooper & Stuart 2003).

Adults are omnivorous, with main food items being zooplankton, aquatic insects, molluscs, small crustaceans (Paratya and Macrobrachium shrimps) and worms as well as algae (Pollard et al., 1980; Merrick 1996; Clunie & Koehn 2001b; NSW DPI 2006). Unlike many other native freshwater species, Silver Perch are not cannibalistic of their young (Rowland & Allan 1994). The Silver Perch shares the traits of partial herbivory and dietary plasticity with the northern Australian species of Terapontidae fishes (Davis et al., 2011), which is less common, however, with the larger-bodied native fish species of Murray-Darling Basin. It could be argued that European Carp (Cyprinus carpio) have replaced the trophic role Silver Perch once occupied across the majority of the Murray-Darling Basin, given the dietary overlap (Fletcher 1986).

The Silver Perch is known to undertake long-distance movements along waterways (Trueman 2011). For example, an adult Silver Perch was Passive Integrated Transponder (PIT) tagged and found to have moved 897 km between Lock 9 and Torrumbarry Weir on the Murray River between October 2016 to January 2017 (MDBA 2017). Both juveniles and adults are known to move large distances. Juveniles move upstream between October to April, while adults move upstream over a shorter timeframe between November to February (Mallen-Cooper et al., 1995, cited in Clunie & Koehn 2001b).

Given the Silver Perch’s historically widespread distribution, it is fair to assume that the species is capable of inhabiting a wide variety of habitats, from meandering alluvial lowland reaches to clear, rocky upland habitats. It has consistently been observed that the species prefers faster flowing, open waters, where there are rapids, runs and races (Clunie & Koehn 2001b; Trueman 2011). The species’ habitat associations with components such as woody debris, aquatic vegetation and riparian vegetation are largely unknown (Clunie & Koehn 2001b). However, Silver Perch do not appear to be dependent on coarse woody snags in the same manner Bidyanus bidyanus (Silver Perch) consultation document Page 9 of 36

Golden Perch and Murray Cod appear to be. Resnagging projects in the middle-Murray River have not reported any response for Silver Perch (Lyon et al., 2019; Raymond et al., 2019). Similarly, mesocosm experiments by Hutchison et al. (2019) found Silver Perch displayed no preference for structure (in this case, rock) over open sand but their results did suggest that the loss of macrophyte habitats caused by European Carp may have had impacts on juvenile Silver Perch. In upland zones where the species was recorded in the past, individuals were generally reported from main river channels rather than tributary creeks (Trueman 2011).

Threats

The primary threats to the Silver Perch include: competition with, and predation by, invasive introduced fish species (Clunie et al., 2002; Vilizzi et al., 2014); barriers to movement causing habitat loss and fragmentation (Clunie & Koehn 2001b; Mallen-Cooper & Stuart 2003), and; altered flow regimes due to water regulation (Walker 1985; Kingsford 2000; Tonkin et al., 2017). Commercial fishing is likely to have impacted the species in the past but has been banned in all jurisdictions of the Murray-Darling Basin since the late-1990s/early-2000s (NSW DPI 2006). Recreational fishing is a likely current threat to the species through incidental capture while targeting other species (Clunie & Koehn 2001b; NSW DPI 2006). It is also highly likely that disease and parasites have impacted heavily upon the wild Silver Perch population across the Murray-Darling Basin (Langdon 1989a; Trueman 2011).

Table 1: Threats impacting the Silver Perch in approximate order of severity of risk, based on available evidence

Number Threat factor Threat Evidence base type and status

1.0 Invasive introduced fish species

1.1 Competition with known After the ‘Boolarra Strain’ of European Carp European Carp past and (Cyprinus carpio) were introduced to a property current near Boolarra, Victoria from Germany in the 1950s and subsequently to the Murray River near Mildura, the species has now spread to almost all parts of the Murray-Darling Basin and is the dominant species in most parts (Wharton 1971; Shearer & Mulley 1978; Rhodes 1999; Koehn et al., 2000; Koehn 2004; Davies et al., 2012). European Carp account for at least 80 percent of fish biomass in many river reaches of the Murray-Darling Basin (Harris & Gehrke 1997; Rolls 2005; Davies et al., 2008; 2012) and in many wetlands the proportion is even higher (Nichols & Gilligan 2004). Dietary analysis for European Carp in Victoria showed that its major food items were similar to those of Silver Perch (Fletcher 1986). Given the current dominance of European Carp within Murray-Daring Basin fish communities, it is highly probable

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populations of medium to large bodied native fish species have been highly impacted.

Other associated impacts of the European Carp on the Murray-Darling Basin include the propensity of the species to disturb native fish habitats by raising turbidity and destroying submergent macrophytes (Roberts et al., 1995; Roberts & Sainty 1996; Vilizzi et al., 2014). European Carp larvae is known to feed upon similar prey items as larvae of two other species of native fish, Maccullochella peelii (Murray Cod) and Macquaria ambigua (Golden Perch) (Tonkin et al., 2006), it is therefore likely that the same competition exists with Silver Perch larvae.

1.2 Predation by known Redfin (Perca fluviatilis) were introduced to the Redfin past and Australian mainland in the 1860s and is known current to prey on many small and juvenile native fish (Clunie et al., 2002). Redfin is also known to facilitate the spread and transmission of Epizootic Haematopoietic Necrosis Virus (EHNV) which is likely to be detrimental to Silver Perch populations (discussed in greater details under Threat 3.1 below).

While Redfin are generally not common in flowing, riverine habitats of the middle-Murray River where the last remaining self-sustaining Murray-Darling Basin population of Silver Perch occurs, they are abundant in many of the Basin’s impoundments where Silver Perch populations are maintained by stocking of juvenile hatchery-raised fish.

2.0 Habitat loss and fragmentation

2.1 Barriers to fish known There have been over 10 000 barriers to fish movement past and movement constructed in the Murray-Darling current Basin for irrigation and drinking water supplies since European settlement (Baumgartner et al., 2014). These structures limit or prevent movement of native fish species. Silver Perch, are known to undergo long-distance movements of up to 900 km and move upstream to spawn (Reynolds 1983; MDBA 2017), barriers to movement therefore represent a substantial threat to the species.

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It is likely that Silver Perch eggs rely on substantially long stretches of uninterrupted river course, to maintain successful drifts while eggs mature and hatch, and then to deliver eggs/larvae into amenable riverine edge habitats in good ecological condition (Clunie & Koehn 2001b; Mallen-Cooper & Stuart 2003). This is likely why the middle-Murray River supports the last clearly self-sustaining population of Silver Perch. The Silver Perch’s eggs are only marginally buoyant and sink to the substrate in the absence of significant current (Lake 1967a; b). Barriers such as dams and weirs may trap drifting eggs and recently hatched larvae, possibly leading to settlement in unfavourable habitat such as anoxic silt of dam/weir pools (Clunie & Koehn 2001b).

3.0 Altered flow regime

3.1 Water storage, known In their natural state, Murray-Darling Basin diversion and past and rivers were characterised by variable flow extraction current patterns and reasonably consistent cyclic increases and decreases in temperature seasonally. Native species such as Silver Perch have adapted to these flow and thermal patterns. Large impoundments and water diversion/extraction have significantly altered these natural flow and temperature patterns (Walker 1985; Kingsford 2000; Lintermans 2013).

Recent research has found that Silver Perch movements in the Murray River are at their highest during periods of high magnitude and extended flooding (Tonkin et al., 2017). Such natural flood events have been largely eliminated by river regulation and the capture of water in slope-zone (200-400 m a.s.l.) by man-made impoundments constructed in most major river valleys across the Murray-Darling Basin.

The importance of appropriate water regimes for the Silver Perch is demonstrated in the positive response recorded following the provision of environmental water over the past decade; such as the higher numbers of young of year fish reported in the Edward-Wakool

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anabranch following delivery of environmental water in 2015/16 (MDBA 2017).

4.0 Disease and parasites

4.1 Epizootic suspected In Australia, the ranavirus EHNV was first Haematopoietic past and isolated in a fish species in 1984, a juvenile Necrosis Virus current Redfin sourced from Lake Nillahcootie near (EHNV) Benalla in Victoria (Langdon et al., 1986). However, from as early as 1972 there were unexplained spring-time fish kills of Redfin in Victoria (Langdon & Humphrey 1987). EHNV is characterised by sudden high mortalities of fish displaying necrosis of the renal haematopoietic tissue, liver spleen and pancreas (Langdon & Humphrey 1987). In laboratory trials, Silver Perch, along with other species of native fish, were found to be highly susceptible to in-water transmission of EHNV and once Silver Perch were infected it resulted in 100 percent fatality rates (Langdon 1989a). It is suspected that the virus contributed to the serious population declines of Silver Perch, and other native fish species, in the decades leading up to the 1980s (Langdon 1989a). EHNV is currently endemic to southeastern Australia.

The collapse of the strong Silver Perch population in the upper Murrumbidgee River (incl. Burrinjuck Reservoir) in the 1980s coincides with the general establishment of the introduced species Redfin (primary vector of EHNV). Eye-witness reports have recalled that in the late-1960s, large numbers of Silver Perch died, exhibiting red skin ulcers, in the river stretch from Canberra downstream past Burrinjuck Reservoir to Berembed Weir (between Wagga Wagga and Narrandera in New South Wales) (Trueman 2011).

The possibility of other ranaviruses or closely related megalocytiviruses being present in Australia cannot be discounted.

4.2 Parasitic suspected Currently, the main suspected parasitic Invertebrates past and invertebrates known to pose threat to Silver current Perch are Lernaea spp. (a.k.a. anchor worm) and Asian Fish Tapeworm.

Lernaeidae (anchor worms) are parasitic copepods which are found infesting freshwater

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fishes worldwide. The females are morphologically highly modified and adapted to a parasitic lifestyle (Ahnelt et al., 2018). These copepods cause the disease Lernaeosis, which can result in serious pathogenic impacts to the host fish (Lester & Hayward 2006).

One species in particular, Lernaea cyprinacea, has been spread globally by human-facilitated introductions of European or Common Carp (Cyprinus carpio) and Goldfish (Carrasius auratus) (Kabata 1979; Langdon 1989b), including to Australia (Rowland & Ingram 1991). This species is known to parasitise native fish species, such as Silver Perch, in southern Australia (Ashburner 1978; Rowland & Ingram 1991; Hassan et al., 2008). Heavy infections with Lernaea resulted in mortalities of Silver Perch broodstock in aquaculture ponds (Callinan 1988).

Asian Fish Tapeworm (Schyzocotyle acheilognathi) is a highly successful parasitic flatworm with broad environmental tolerances and is reported in a wide spectrum of freshwater fishes (Kuchta et al., 2018). European Carp, Goldfish or Eastern Gambusia (Gambusia holbrooki) have been implicated as the source of, and a vector for, the introduced tapeworm Schyzocotyle acheilognathi which has been recorded in a number of native fish species (Dove et al., 1997; Dove & Fletcher 2000) but not yet confirmed in Silver Perch. Given the Asian Fish Tapeworm’s low host specificity, it potentially is threatening Silver Perch populations and has been shown to be most pathogenic (causing disease) in fish species to which have newly become hosts in Australia and other parts of the world where it has been introduced (Kutcha et al., 2018).

Silver Perch are susceptible to other parasitic infestations in aquaculture conditions, and the extent to which these threaten the species in the wild is unclear. Some of these include monogeans (skin and gills flukes) such as Lepidotrema bidyana and the copepod parasite Ergasilus spp. (Gill Lice)

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4.3 Parasitic suspected The parasitic protozoans, Chilodonella protozoans past and hexasticha and Ichthyophthirius multifiliis current (causes the disease commonly known as white spot or ich), infect surface tissues and gills of fish and are known to have caused mass mortalities of Silver Perch in aquaculture operations in Australia (Callinan 1988). Outbreaks attributed to either Chilodonella or Icthyophthirius protozoans have been recorded as the cause for Australian native freshwater fish kills in the wild (Callinan 1988). The ciliate Ambiphyra spp. is a problem for Silver Perch in aquaculture, it is currently unclear whether this species represents a threat to wild individuals.

5.0 Fishing

5.1 Commercial Suspected There are varying reports indicating that fishing past historically, Silver Perch was a significant component of total commercial fish catch in the Murray-Darling Basin (Cadwallader 1977). It is generally considered that there was a significant commercial catch of Silver Perch in New South Wales and South Australia, with a smaller catch in Victoria (Clunie & Koehn 2001a). Between 1961-75, Silver Perch were the fourth most important commercially exploited inland freshwater species (Pollard et al., 1980). Commercial fishing for this species did not occur in Queensland (Clunie & Koehn 2001a). J.O. Langtry’s surveys in 1949-50 noted the species was a mobile, unpredictable target for commercial fishers, and were caught in large numbers when migrating (Cadwallader 1977).

Commercial fishing catches of Silver Perch across the Murray-Darling Basin declined from the early 1960s to the 1980s (Clunie & Koehn 2001a). In New South Wales, following the collapse of the Silver Perch stocks in the mid- 1980s, fishers introduced a voluntary ban on landing the species in 1993 (NSW DPI 2006). In 1998, NSW Fisheries banned the capture and sale of silver perch from riverine habitats and by September 2001, commercial fishing for all inland native fish species in New South Wales was banned (NSW DPI 2006). Commercial harvest of Silver Perch was also

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phased out in South Australia in 1997, and in Victoria in 1998 (NSW DPI 2006).

Commercial fishing is therefore a suspected past contributing threat to the decline of Silver Perch in the Murray-Darling Basin (NSW DPI 2006) 5.2 Incidental capture Suspected Although recreational fishing pressure may not in recreational past, have been a key threat to Silver Perch before fishing current the historic declines in the species’ abundance and future and distribution occurred, the species is expected to have become more vulnerable to recreational fishing pressure due to its more recent range and population contraction (Clunie & Koehn 2001b). Now that the species’ wild, self-sustaining population is mainly concentrated within the middle-Murray River, where considerable recreational fishing pressure exists for other native fish species such as Murray Cod and Golden Perch, recreational fishing poses a threat to the species, which is caught and released incidentally (NSW DPI 2006). Depending upon handling practices, the species is likely suffering a continuing level of post-release mortality (NSW DPI 2006). Another potential impact of incidental capture in recreational fishing on Silver Perch, is the incidental catch and release of fish before or during the species’ breeding cycle, which may result in failure of those released fish to breed (NSW DPI 2006); due to egg resorption and other physiological impacts caused by the stress of capture.

6.0 Climate change associated events

6.1 Increased Suspected Bushfires experienced during the 2019/20 intensity/frequency current bushfire season burnt more than 10 million of bushfire and future hectares of land in southern Australia (CSIRO 2020). While climate change does not directly cause bushfire, it has caused an increase in the occurrence of extreme fire weather and in the length of the fire season across large parts of Australia since the 1950s (CSIRO 2020). In 2019, the annual national mean temperature was 1.52°C above average (BOM 2020).

Climate change has driven longer, more intense fire seasons and an increase in the

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average number of elevated fire weather days, as measured by the Forest Fire Danger Index (FFDI) (CSIRO 2020). The highest annual accumulated FFDI was recorded in 2019 (CSIRO 2020).

Bushfire can adversely affect stream habitat by increasing water temperature, altering water chemistry (Lyon & O’Connor 2008), and creating sediment/ash runoff ‘slugs’ that can form in waterways following rainfall on burnt areas (Lyon & O’Connor 2008; Alexandra & Finlayson 2020). Sediment slugs have been found to impact aquatic ecosystems up to 80 km downstream of burnt areas (Lyon & O’Connor 2008).

In 2019-20, following years of drought (DPI 2020), catastrophic bushfire conditions culminated in fires that covered an unusually large area of eastern and southern Australia. In many places, the fires burnt with high intensity. While the full impact of the 2019-20 bushfires is yet to be determined, initial analysis estimates that impacts to areas where Silver Perch occur are currently low (DAWE 2020). Bushfire seasons of this intensity and scale are likely to increase as a result of climate change (CSIRO 2020).

6.2 Changing rainfall Suspected Freshwater ecosystems are particularly patterns current vulnerable to climate change because they are and future isolated and fragmented within a terrestrial landscape (Morrongiello et al., 2011). Surface water, which determines the quality and availability of aquatic habitat, depends heavily on rainfall and temperature regimes which are predicted to drastically change under climate change predictions (Carpenter et al., 1992; Hobday & Lough 2011). Climate change projections for the Murray-Darling Basin predict increases in temperature and evaporation and less rainfall and snowfall, which will likely result in reduced runoff to rivers and wetlands especially in the southern Basin (CSIRO 2008; Dunlop & Brown 2008; Morrongiello et al., 2011). Median runoff is predicted to decline by up to 12% and flood frequency is predicted to decrease (Balcombe et al., 2011). Extreme events such as storms (and associated floods) and droughts are projected to rise in frequency

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and/or intensity under climate change (Aldous et al., 2011; Hobday & Lough 2011).

Given that the remaining Silver Perch population remains concentrated in the middle- Murray River, there is a high likelihood that severe impacts to the species if there is regional changing rainfall patterns driven by climate change to the southern Murray-Darling Basin.

Assessment of available information in relation to the EPBC Act Criteria and Regulations

Criterion 1. Population size reduction (reduction in total numbers) Population reduction (measured over the longer of 10 years or 3 generations) based on any of A1 to A4 Critically Endangered Endangered Vulnerable Very severe reduction Severe reduction Substantial reduction A1 ≥ 90% ≥ 70% ≥ 50% A2, A3, A4 ≥ 80% ≥ 50% ≥ 30% A1 Population reduction observed, estimated, inferred or suspected in the past and the causes of the reduction (a) direct observation [except A3] are clearly reversible AND understood AND ceased. A2 Population reduction observed, estimated, inferred (b) an index of abundance appropriate to or suspected in the past where the causes of the the taxon reduction may not have ceased OR may not be based understood OR may not be reversible. (c) a decline in area of occupancy, extent on any of occurrence and/or quality of habitat A3 Population reduction, projected or suspected to be of the met in the future (up to a maximum of 100 years) [(a) following cannot be used for A3] (d) actual or potential levels of exploitation A4 An observed, estimated, inferred, projected or (e) the effects of introduced taxa, suspected population reduction where the time period hybridization, pathogens, pollutants, must include both the past and the future (up to a competitors or parasites max. of 100 years in future), and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible.

Evidence:

Given known records for maximum age of Silver Perch is 27 years in a translocated population and 17 years in a natural wild population (Mallen-Cooper & Stuart 2003), it is estimated that 22 years (half way between these points) may be used as a conservative yet plausible theoretical maximum age potential for the wild population. The age at first sexual maturity has been recorded at five years for females in the wild population (Mallen-Cooper & Stuart 2003). Using these estimates, the generation length for Silver Perch is estimated to be approximately between 12-15 years. This was determined using the IUCN Red List Guidelines prescribed formula: age of first reproduction+ z*(length of reproductive period) with z between 0.4-0.6 (IUCN S&PS 2017). The IUCN guidance notes that z is usually less than 0.5 and the higher values are where the relative fecundity is skewed towards older age classes. However for relatively long-lived fish species, where fecundity output increases with age and body size, z may be higher than 0.5. A range between 0.4 and 0.6 for z is therefore considered the most plausible estimate, (noting an argument could be made for an even higher z value). Three

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generations is therefore estimated to be 36-45 years. The timeframe for assessment against Criterion A2 is therefore from between 1974-1983 to 2019.

The inference of Tonkin et al. (2017) that the maximum age of Silver Perch was only 7 years were much less than those of Mallen-Cooper & Stuart (2003) on fish sampled in the same region. It is unclear whether the extreme blackwater events which occurred in the southern Murray-Darling Basin between 2010-2012 may have influenced the findings of Tonkin et al. (2017) regarding the maximum age potential of Silver Perch in the wild.

The conditions required to apply criterion A1 are not met as the causes (i.e. threats) of the Silver Perch reduction in numbers have not ceased and are still impacting the species. Some causes remain not completely understood, namely the presence of introduced fish species, habitat fragmentation, and disease and parasites. Assessment against A2 presents the most valid subcriterion, given population reduction is estimated based on observations of presence and absence and the causes of decline have not ceased.

While there is evidence that the naturally-occurring Silver Perch population declined in numbers from being very abundant and widespread in the early-1900s to the early 1980s (see above under ‘Historical distribution’), since the early-1980s the decline has intensified and the population has been reduced to primarily occur in the middle reach of the Murray River between Mulwala Weir downstream to the South Australian border (Mallen-Cooper & Stuart 2003; Tonkin et al., 2017). Despite this stretch of the Murray River being the last remaining stronghold for the species, recent research has found that there is a lack of individuals aged greater than seven years in the population (Tonkin et al., 2017), which is alarming given the species’ potential maximum age in the wild is at least 17 years and is likely to be higher (given a 27 year old individual was recorded from the translocated population in Cataract Reservoir). This finding may indicate that the effective length of time in which each mature Silver Perch can contribute to breeding and recruitment has been shortened.

In the past three generations, since 1983 (36 years ago), self-sustaining local populations of Silver Perch, which had been persisting, have become functionally extinct in the Paroo, Warrego, and Barwon-Darling (i.e. Darling River upstream of Menindee) river catchments (Gehrke et al., 1995; 1999; Clunie & Koehn 2001b; NSW DPI 2006). Recent large-scale fish kill events in the Lower Darling River downstream from Menindee, including considerable numbers of Silver Perch (Vertessy et al., 2019), suggest that numbers of Silver Perch which had persisted in this stretch until 2019 may have now declined significantly. Recent sampling in the Lower Darling River from the town of Pooncarie upstream to Menindee only found five Silver Perch individuals (out of the 3345 fish caught) (MDBA pers. comm., 2019), indicating that the viability of this population is precarious. Based on these survey results, the long-term viability of this population is questionable, and the fish kill events which occurred during the 2018/19 summer may have further impacted any remaining Silver Perch population in this region.

Commercial fishing catch of Silver Perch of the South Australian fishery operating in the Lower Murray River crashed in the mid-1980s to very low levels (Hammer et al., 2009) but there are indications from recent surveys that the species has recovered slightly (Giri & Hall 2015; Zampatti et al., 2018). Most Silver Perch caught by recreational fishers are released in South Australia, given the species’ protected status in that jurisdiction (Giri & Hall 2015).

It is likely that any remaining local populations previously reported by recreational fishers over the past 36 years in the Bogan, Macquarie, Castlereagh, Gwydir, Culgoa-Narran catchments, which collectively represent large areas and likely supported substantial numbers of Silver Perch, have gone extinct. Since 2002 no individuals have been recorded from these areas (Gilligan in prep. 2012, cited in TSSC 2013). In the Murrumbidgee River upstream of Burrinjuck Bidyanus bidyanus (Silver Perch) consultation Page 19 of 36

Reservoir, the local population of Silver Perch is considered to have declined substantially between 1984 and 1988 and ongoing monitoring has not detected the species since (Lintermans 2000; 2002; ACT Government 2018). The species is now considered functionally extinct in this region, and any recent sightings or captures are assumed displaced individuals from the stocked population occurring in Googong Reservoir (ACT Government 2018). Similarly, monitoring in 2004 within Burrinjuck Reservoir failed to detect any Silver Perch (Gilligan 2005) despite large catches previously reported in this reservoir by recreational fishers in 1985 (Canberra Times 1985).

In Victoria, recent records of small numbers of juveniles indicate that there has been some recovery and recruitment may be occurring into tributaries of the Murray River where the stronghold local population remains. A breeding population of Silver Perch exists in the lower Goulburn River, albeit in low numbers (Koster et al., 2012). Juvenile Silver Perch were recorded at monitoring sites in the lower Campaspe River in 2017 for the first time in ten years (Shepparton News 2017; Vic DELWP 2018).

In summary, the available evidence indicates localised functional extinctions within multiple river valleys across the Murray-Darling Basin and suspected significant declines from fish kill events during the summer of 2019-20. There is however evidence of some recovery in Silver Perch populations in the very lower reaches of the Victorian tributaries of the Murray River, such as the Goulburn River. There is no evidence that stocked impoundment populations are self-sustaining and are therefore considered to not contribute to the viability of the wild population. The currently available information on Silver Perch populations is provided in Table 2, below.

Table 2: Summary of Silver Perch population information across the Murray-Darling Basin in the past three generations (i.e. 36-45 years).

Population Trend Evidence Source Paroo 100% decline Self-sustaining local populations of Silver Gehrke et al. (1995), Perch, which had been persisting in the (1999), Clunie & Koehn 1980s, have become functionally extinct. (2001b), NSW DPI (2006)

Warrego 100% decline Self-sustaining local populations of Silver Gehrke et al. (1995), Perch, which had been persisting in the (1999), Clunie & Koehn 1980s, have become functionally extinct. (2001b), NSW DPI (2007)

Barwon-Darling 100% decline Self-sustaining local populations of Silver Gehrke et al. (1995), (1999) Perch, which had been persisting in the Clunie & Koehn (2001b), 1980s, have become functionally extinct. NSW DPI (2008)

Lower Darling Not specified, Recent large-scale fish kill events in the Vertessy et al. (2019), possibly 50- Lower Darling River downstream from MDBA pers. comm. (2019) 95% decline Menindee, including considerable numbers of Silver Perch, suggest that populations which had persisted in this stretch until 2019 may have now declined significantly. Recent sampling in the Lower Darling River from the town of Pooncarie upstream to Menindee only found five Silver Perch individuals (out of the 3345 fish caught).

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Population Trend Evidence Source Lower Murray Stable or Commercial fishing catch of Silver Perch of Giri & Hall (2015), Zampatti increase the South Australian fishery operating in the et al. (2018) Lower Murray River declined in the mid- 1980s to very low levels (Hammer et al., 2009), but there are recent indications from recreational fishing surveys in 2013/14 that the species is slightly recovering in this area.

Bogan 100% decline Catchment once supported substantial Gilligan in prep. (2012), numbers of Silver Perch, but since 2002 no cited in TSSC (2013) individuals have been recorded from these areas.

Macquarie 100% decline Once supported substantial numbers of Gilligan in prep. (2012), Silver Perch downstream of Lake cited in TSSC (2013) Burrendong, but since 2002 no individuals have been recorded from these areas.

Castlereagh 100% decline Large areas of catchment likely supported Gilligan in prep. (2012), substantial numbers of Silver Perch, but cited in TSSC (2013) since 2002 no individuals have been recorded from these areas

Gwydir 100% decline Large areas likely supported substantial Gilligan in prep. (2012), numbers of Silver Perch, but since 2002 no cited in TSSC (2013) individuals have been recorded from these areas Culgoa-Narran 100% decline Large areas likely supported substantial Gilligan in prep. (2012), numbers of Silver Perch, but since 2002 no cited in TSSC (2013) individuals have been recorded from these areas

Murrumbidgee 100% decline Silver Perch is considered to have declined Lintermans (2000), (2002), River upstream substantially in the Murrumbidgee River in ACT Government (2018) of Burrinjuck the river stretch upstream from Burrinjuck Reservoir Reservoir to within the ACT between 1984 and 1988 and ongoing monitoring has not detected the species since.

Burrinjuck 100% decline Monitoring in 2004 failed to detect any Silver Canberra Times (1985), Reservoir Perch in Burrinjuck Reservoir despite large Gilligan (2005) catches still being previously reported in abundant numbers this reservoir by recreational fishers in 1985. Lower Goulburn Stable A breeding population of Silver Perch exists, Koster et al. (2012) River albeit in low numbers.

Lower Stable or Juvenile Silver Perch were recorded at Shepparton News (2017), Campaspe River increase monitoring sites in 2017, likely derived from Vic DELWP (2018) the middle-Murray population, for the first time in ten years.

It appears therefore that overall, the national wild Silver Perch population has undergone a severe reduction of greater than or equal to 50 percent in the past 36-45 years (i.e. since between 1974-1983). The data presented above appear to demonstrate that the species is eligible for listing as Endangered under the relevant elements of this criterion (A2,(a),(c),(e)). However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

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Criterion 2. Geographic distribution as indicators for either extent of occurrence AND/OR area of occupancy Critically Endangered Vulnerable Endangered Restricted Limited Very restricted B1. Extent of occurrence (EOO) < 100 km2 < 5,000 km2 < 20,000 km2 B2. Area of occupancy (AOO) < 10 km2 < 500 km2 < 2,000 km2 AND at least 2 of the following 3 conditions indicating distribution is precarious for survival: (a) Severely fragmented OR Number = 1 ≤ 5 ≤ 10 of locations (b) Continuing decline observed, estimated, inferred or projected in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals (c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations;( iv) number of mature individuals

Evidence:

The extent of occurrence (EOO) is estimated to be 53,450 km2, and the area of occupancy (AOO) is estimated to be 7024 km2 (DAWE 2021). The EOO was calculated using a minimum convex hull while the AOO was based on the mapping of point records since 1999, obtained from state governments, museums and CSIRO, and extrapolating those point records along river networks known to contain a self-sustaining wild population using 2x2 km grid cell method (based on the IUCN Red List Guidelines 2019). Therefore, neither EOO nor AOO appears to classify as limited, restricted or very restricted.

The data presented above appear to demonstrate the species is not eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 3. Population size and decline

Critically Endangered Vulnerable Endangered Low Limited Very low Estimated number of mature individuals < 250 < 2,500 < 10,000 AND either (C1) or (C2) is true C1 An observed, estimated or projected Very high rate High rate Substantial rate continuing decline of at least (up to 25% in 3 years or 1 20% in 5 years or 2 10% in 10 years or 3 a max. of 100 years in future) generation generation generations (whichever is longer) (whichever is (whichever is longer) longer) C2 An observed, estimated, projected or inferred continuing decline AND its geographic distribution is precarious for its survival based on at least 1 of the following 3 conditions: (i) Number of mature individuals in ≤ 50 ≤ 250 ≤ 1,000 each subpopulation (a) (ii) % of mature individuals in one 90 – 100% 95 – 100% 100% subpopulation = (b) Extreme fluctuations in the number of mature individuals

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Evidence:

The data presented above appear to be insufficient to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 4. Number of mature individuals

Critically Endangered Vulnerable Endangered Very Low Low Extremely low

Number of mature individuals < 50 < 250 < 1,000

Evidence:

The data presented above appear to be insufficient to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 5. Quantitative Analysis

Critically Endangered Endangered Vulnerable Immediate future Near future Medium-term future ≥ 50% in 10 years or ≥ 20% in 20 years or Indicating the probability of extinction in 3 generations, 5 generations, ≥ 10% in 100 years the wild to be: whichever is longer whichever is longer (100 years max.) (100 years max.)

Evidence:

Population viability analysis appears not to have been undertaken, there are insufficient data to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Conservation Actions

Recovery Plan

A revised decision about whether there should be a recovery plan for the Silver Perch has not yet been determined. Currently, there is a decision to have a recovery plan for this species. A recovery plan has not been implemented yet, postponed while a review of the species’ conservation status was undertaken. The purpose of this consultation document is to elicit additional information to help inform this decision.

Primary Conservation Actions

The middle-Murray population of Silver Perch is protected and impacts from river regulation and recreational fishing are minimised.

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New, self-sustaining populations of Silver Perch are established through conservation stocking and translocations in multiple locations throughout the Murray-Darling Basin.

Conservation Actions

Conservation and Management priorities

• Invasive introduced fish species

o Implement programs to reduce populations of European Carp and Redfin in areas where Silver Perch occur or in areas where conservation stockings are planned for.

• Habitat loss and fragmentation

o Implement management and engineering solutions to physical barriers to fish movement, such as dams, weirs, culverts to improve the connectivity of waterways Silver Perch utilise. Focus should be given to solving fish passage up- and downstream across the tall dam barriers located in the slope zones (200-400 m a.s.l.) of major river valleys in the Murray-Darling Basin.

o Avoid the construction of new structures which form a barrier to fish movement at any life stage (egg, larvae, juvenile, adult).

o Avoid installing ‘undershot’ weirs that kill drifting native fish larvae, and modify current undershot weirs to an ‘overshot’ design

• Altered flow regime

o Use environmental water allocations to optimise natural flood events to promote Silver Perch spawning and recruitment.

o Manage regulated waterways so that there is a river rise in level and flow in the spring season.

• Disease and parasites

o Develop and implement appropriate hygiene protocols for all fish stocking and translocation activities so that the remaining Silver Perch population is protected from further outbreaks of Epizootic Haematopoietic Necrosis Virus (EHNV) and other viruses and parasites.

o Investigate control measures for Lernaea (aka ‘anchor worm’) and Asian fish tapeworm.

o Investigate other diseases, bacteria and fungi that are common in an aquaculture setting and their potential risk in the wild or researching their effects on silver perch, especially if some of the agents are emerging.

Stakeholder Engagement

• Engage with private landholders and land managers responsible for the land adjacent to waterways where Silver Perch populations occur and encourage these key stakeholders to support conservation of the species.

• Produce and disseminate educational materials amongst recreational fishing groups, community organisations, Indigenous groups, agricultural groups and resource

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management groups about the historical distribution and abundance of the species, and the continued threats to survival it faces.

• Engage with commercial hatcheries producing Silver Perch so there is potential for involvement in conservation stockings to increase the numbers available, given that government hatchery production has been limited to date.

Survey and Monitoring priorities

• Implement a long-term, monitoring program focussed on Silver Perch which is able to record the size and importance of natural, self-sustaining populations and stocked populations.

• Investigate the fate of released hatchery-produced fingerlings and translocated individuals.

Information and Research priorities

• Increase understanding of the recruitment ecology of Silver Perch, and the potential for managed flow events (both flood and within-channel) to facilitate spawning and recruitment.

• Research genetic structuring in Silver Perch, including within wild, translocated and stocked populations occurring throughout southeastern Australia.

• Better understand competition and predation upon Silver Perch by all introduced fish species of the Murray-Darling Basin.

• Improve knowledge about the Silver Perch’s life cycle and how it relates to its broadscale movements. Identify the triggers, and barriers, for such movement, and best habitats for spawning in and outside the species’ current extent of occurrence to inform future management.

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References

Advocate (1932). In Defence of the Kelly Gang. Advocate newspaper, Burnie, Tasmania. Wednesday 19 October 1932, p. 9. Aldous, A., Fitzsimons, J., Richter, B., & Bach, L. (2011). Droughts, floods and freshwater ecosystems: evaluating climate change impacts and developing adaptation strategies. Marine and Freshwater Research 62, 223-231. Alexandra, J., & Finlayson, C.M. (2020). Floods after bushfires: rapid responses for reducing impacts of sediment, ash, and nutrient slugs. Australasian Journal of Water Resources 19, 1-3. Allen, G.R., Midgley, S.H., & Allen, M. (2002). Field Guide to the Freshwater Fishes of Australia. Western Australian Museum, Perth. Anhelt, H., Konecny, R., Gabriel, A., Bauer, A., Pompei, L., Lorenzoni, M., & Sattmann, H. (2018). First report of the parasitic copepod Lernaea cyprinacea (Copepoda: Lernaeidae) on gobioid fishes (Teleostei: Gobonellidae) in southern Europe. Knowledge & Management of Aquatic Ecosystems 419 (34), 1-6. Armidale Express (1874). Squatting in the North. Armidale Express and New England General Advertiser newspaper, New South Wales. Friday 8 May 1874, p. 7. Ashburner, L.D. (1978). Management and diseases of hatchery fish. In: Reynolds, L.F. (ed.) (1978). Proceedings No. 36 of Course for Veterinarians: Fauna Part B. pp. 387-449. Australian Capital Territory Government (ACT Government) (2018). Silver Perch Bidyanus bidyanus Action Plan. In: ACT Aquatic and Riparian Conservation Strategy and Action Plans, Part B, pp. 205-219. Australian Women’s Weekly (AWW) (1962). Golden Age of a Sheep Station. The Australian Women’s Weekly magazine, Sydney, New South Wales. Wednesday 27 June 1962, p. 16-18, 75. Balcombe, S.R., Sheldon, F., Capon, S.J., Bond, N.R., Hadwen, W.L., Marsh, N., & Bernays, S.J. (2011). Climate-change threats to native fish in degraded rivers and floodplains of the Murray-Darling Basin, Australia. Marine and Freshwater Research 62, 1099-1114. Balonne Beacon (1940). Golden Carp, Does It Harm Murray Cod. Balonne Beacon newspaper, St. George, Queensland. Thursday 8 August 1940, p. 6. Bathurst Free Press & Mining Journal (BFP) (1890). Nyngan. The Bathurst Free Press and Mining Journal semiweekly newspaper, Bathurst, New South Wales. Saturday 11 January 1890, p. 2. Baumgartner, L., Zampatti, B., Jones, M., Stuart, I., & Mallen-Cooper, M. (2014). Fish passage in the Murray-Darling Basin, Australia: Not just an upstream battle. Ecological Management & Restoration 15, 28-39. Bendigo Advertiser (1879). The Bendigo Advertiser. The Bendigo Advertiser daily newspaper, Bendigo, Victoria. Wednesday 26 November 1879. p. 2. Bennett, G. (1834). Wanderings in New South Wales, Batavia, Pedir Coast, Singapore, and China; Being the Journal of a Naturalist in those Countries, during 1832, 1833, and 1834. Richard Bentley, London. Bureau of Meteorology (BOM) (2020). 2019 annual climate facts and events. Australian Government Bureau of Meteorology, Viewed: 26 June 2020 Available on the Internet at: http://www.bom.gov.au/climate/current/annual/aus/ Bidyanus bidyanus (Silver Perch) consultation Page 26 of 36

Cadwallader, P.L. (1977). J.O. Langtry’s 1949–50 Murray River Investigations. Fisheries and Wildlife Paper No. 13. Fisheries and Wildlife Division, Victoria. Callinan, R.B. (1988). Diseases of Australian native fish. In: Fish Diseases: Post Graduate Committee in Veterinary Science. Refresher Course for Veterinarians, University of Sydney. Canberra Times (1972). Changed laws announced for NSW areas. The Canberra Times daily newspaper, Australian Capital Territory. Friday 17 March 1972, p. 17. Canberra Times (1985). Perch ‘committing suicide’ at Burrinjuck Dam. The Canberra Times daily newspaper, Australian Capital Territory. Thursday 17 October 1985. p. 29. Carpenter, S.R., Fisher, S.G., Grimm, N.B., & Kitchel, J.F. (1992). Global change and freshwater ecosystems. Annual Review of Ecology and Systematics 23, 119-139. Catholic Press (1920). The Maranoa District (South-Western Queensland), Its Wonderful Pastoral and Agricultural Resources and its Illimitable Possibilities. The Catholic Press weekly newspaper, Sydney, New South Wales. Thursday 2 December 1920, p. 12. Clunie, P., & Koehn, J. (2001a). Silver Perch — A Recovery Plan, Volume 1. Murray Darling Basin Commission, Canberra. Clunie, P., & Koehn, J. (2001b). Silver Perch — A Resource Document, Volume 2. Murray Darling Basin Commission, Canberra. Clunie, P., Stuart, I., Jones, M., Crowther, D., Schreiber, S., McKay, S., O’Connor, J., McLaren, D., Weiss, J., Gunasekera, L., & Roberts, J. (2002). A risk assessment of the impacts of pest species in the riverine environment in the Murray-Darling Basin. Department of Natural Resources and Environment, Arthur Rylah Institute for Environmental Research, Heidelberg. CSIRO (2008). Water Availability in the Murray-Darling Basin. A report from CSIRO to the Australian Government. CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 67pp. CSIRO (2020). The 2019-20 bushfires: a CSIRO explainer. February 2020. Viewed: 26 June 2020 Available on the Internet at: https://www.csiro.au/en/Research/Environment/Extreme-Events/Bushfire/preparing-for- climate-change/2019-20-bushfires-explainer Daily Observer (1917). Notice to Fisherman. The Daily Observer daily newspaper, Tamworth, New South Wales. Saturday 24 February 1917. p. 1. Davies, P.E., Harris, J.H., Hillman, T.J., & Walker, K.F. (2008). SRA Report 1: A Report on the Ecological Health of Rivers in the Murray–Darling Basin, 2004–2007. Prepared by the Independent Sustainable Rivers Audit Group for the Murray– Darling Basin Ministerial Council. Davies, P.E., Stewardson, M.J., Hillman, T.J., Roberts, J.R., & Thoms, M.C. (2012). Sustainable Rivers Audit 2: The ecological health of rivers in the Murray–Darling Basin at the end of the Millennium Drought (2008–2010). Prepared by the Independent Sustainable Rivers Audit Group for the Murray-Darling Basin, Murray-Darling Basin Authority, Canberra. Davis, A.M., Pearson, R.G., Pusey, P.J., Perna, C., Morgan, D.L., & Burrows, D. (2011). Trophic ecology of northern Australia’s terapontids: ontogenetic dietary shifts and feeding classification. Journal of Fish Biology 78, 265-286.

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Department of Agriculture, Water and the Environment (DAWE) (2020). Revised provisional list of animals requiring urgent management intervention. Australian Government Department of Agriculture, Water and the Environment, Canberra. Viewed: 29 June 2020 Available on the Internet at: https://www.environment.gov.au/biodiversity/bushfire-recovery/priority-animals Department of Agriculture, Water and the Environment (DAWE) (2021). Area of Occupancy and Extent of Occurrence for Bidyanus bidyanus (Silver Perch) 1999 – 2019. Unpublished report, Australian Government Department of Agriculture, Water and the Environment, Canberra. Dove, A.D.M., Cribb, T.H., Mockler, S.P., & Lintermans, M. (1997). The Asian Fish Tapeworm, Bothriocephalus acheilognathi, in Australian freshwater fishes. Marine and Freshwater Research 48(2), 181-183. Dove, A.D.M., & Fletcher, A.S. (2000). The distribution of the introduced tapeworm Bothriocephalus acheilognathi in Australian freshwater fishes. Journal of Helminthology 74, 121-127. Dubbo Dispatch and Wellington Independent (DD&WI) (1899). Warren. Dubbo Dispatch and Wellington Independent semiweekly newspaper, Dubbo, New South Wales. Friday 19 May 1899, p. 3. Dubbo Liberal and Macquarie Advocate (DL&MA) (1950). Gilgandra was “Invaded” on Saturday. The Dubbo Liberal and Macquarie Advocate daily newspaper, Dubbo, New South Wales. Tuesday 30 May 1950, p. 2. Dunlop, M., & Brown, P.R. (2008). Implications of climate change for Australia’s National Reserve System: A preliminary assessment. Report to the Department of Climate Change, February 2008. Department of Climate Change, Canberra, Australia. Evening News (1870). Bathurst to Tambaroora. The Evening News daily newspaper, Sydney, New South Wales. Tuesday 2 August 1970, p. 4. Fletcher, A.R. (1986). Effects of introduced fish in Australia. In: De Deckker, P., & Williams, W.D. (eds.) Limnology in Australia. CSIRO and Dr. W. Junk Publishers, Melbourne. pp. 231- 238. Freeman’s Journal (1906). The Bush Fisherman. Freeman’s Journal newspaper, Sydney, New South Wales. Saturday 15 December 1906, pp. 66-67. Gehrke, P.C., Brown, P., Schiller, C.B., Moffatt, D.B., & Bruce, A.M. (1995). River regulation and fish communities in the Murray-Darling River System, Australia. Regulated Rivers: Research & Management 11, 363-375. Gehrke, P.C., Schiller, C.B., & Brown, P. (1999). Native Fish and River Flows: The Paroo Perspective. In: Kingsford, R.T. (ed.) (1999). A Free-flowing River: The Ecology of the Paroo River. National Parks and Wildlife Service, Sydney, p. 201-222. Gilligan, D.M. (2005). Fish Communities of the Murrumbidgee catchment: Status and trends. Fisheries Final Report Series No.75. New South Wales Department of Primary Industries. Giri, K., & Hall, K. (2015). South Australian Recreational Fishing Survey. Fisheries Victoria Internal Report Series No. 62. Goulburn Herald and Chronicle (GH&C) (1867). Marsden, Bland. The Goulburn Herald and Chronicle semiweekly newspaper, New South Wales. Saturday 8 June 1867, p. 5. Günther, A. (1859). Catalogue of the Acanthopterygian fishes in the collection of the British Museum, vol. 1: Gasterosteidae, Berycidae, Percidae, Aphredoderidae, Pristipomatidae, Mullidae, Sparidae. Taylor and Francis, Fleet Street, London. 524 pp.

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Hammer, M., Wedderburn, S., & van Weenen, J. (2009). Action Plan for South Australian Freshwater Fishes. Native Fish Australia (SA) Inc., Adelaide and Department of Environment and Natural Resources, Government of South Australia. Harris, J.H., & Gehrke, P.C. (eds.) (1997). Fish and rivers in stress: The New South Wales Rivers Survey. NSW Fisheries Department, Cooperative Research Centre for Freshwater Ecology, NSW Resource and Conservation Assessment Council. Hassan, M., Beatty, S.J., Morgan, D.L., Doupe, R.G., & Lymbery, A.J. (2008). An introduced parasite, Lernaea cyprinacea L., found on native freshwater fishes in south west Western Australia. Journal of the Royal Society of Western Australia 91, 149-153. Hobday, A.J., & Lough, J.M. (2011). Projected climate change in Australian marine and freshwater environments. Marine and Freshwater Research 62, 1000-1014. Hutchison, M., Norris, A., & Nixon, D. (2019). Habitat preferences and habitat restoration options for small-bodied and juvenile fish species in the northern Murray-Darling Basin. Ecological Management and Restoration 21, 51-57. International Union for Conservation of Nature (IUCN) Standards and Petitions Subcommittee (IUCN S&PS) (2017). Guidelines for Using the IUCN Red List Categories and Criteria, Version 13. Prepared by the Standards and Petitions Subcommittee. Available online at http://www.iucnredlist.org/documents/RedListGuidelines.pdf Kabata, Z. (1979). Parasitic copepoda of British fishes. Ray Society, London. 468 pp. Kingsford, R.T. (2000). Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia. Austral Ecology 25, 109-127. Koehn, J.D. (2004). Carp (Cyprinus carpio) as a powerful invader in Australian waterways. Freshwater Biology 49, 882-894. Koehn, J., Brumley, A., & Gehrke, P. (2000). Managing the Impacts of Carp. Bureau of Rural Sciences, Department of Agriculture, Fisheries and Forestry, Canberra. Koster, W., Crook, D., Dawson, D., & Moloney, P. (2012). Status of fish populations in the lower Goulburn River (2003-2012). Arthur Rylah Institute for Environmental Research Unpublished Client Report for Goulburn Broken Catchment Management Authority, Department of Sustainability and Environment, Heidelberg, Victoria. Kutcha, R., Choudhury, A., & Scholz, T. (2018). Asian fish tapeworm: the most successful invasive parasite in freshwaters. Trends in Parasitology 34, 511-523. Lake, J.S. (1967a). Rearing experiments with five species of Australian freshwater fishes. I. Inducement to spawning. Australian Journal of Marine and Freshwater Research 18, 137-153. Lake, J.S. (1967b). Rearing experiments with five species of Australian freshwater fishes. II. Morphogenesis and ontogeny. Australian Journal of Marine and Freshwater Research 18, 155-173. Lake, J.S. (1978). Australian Freshwater Fishes. Thomas Nelson Australia Pty Ltd, Melbourne, Australia. Langdon, J.S. (1989a). Experimental transmission and pathogenicity of epizootic haematopoietic necrosis virus (EHNV) in Redfin Perch Perca fluviatilis L., and 11 other teleosts. Journal of Fish Diseases 12(4), 295-310. Langdon, J.S. (1989b). Prevention and control of fish diseases in the Murray-Darling Basin. In: Proceedings of the workshop on native fish management, Canberra, 16-18 June 1988. Murray-Darling Basin Commission, Canberra. Langdon, J.S., & Humphrey, J.D. (1987). Epizootic haematopoietic necrosis, a new viral disease in redfin perch, Perca fluviatilis L., in Australia. Journal of Fish Diseases 10(4), 289-297.

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Langdon, J.S., Humphrey, J.D., Williams, L.D., Hyatt, A.D., & Westbury, H.A. (1986). First virus isolation from Australian fish: an iridovirus-like pathogen from redfin perch, Perca fluviatilis L. Journal of Fish Diseases 9, 263-268. Leader (1886). Angling. Murray Fishing. Leader weekly newspaper, Melbourne, Victoria. Saturday 25 December 1935, p. 23. Lester, R.G., & Hayward, C.J. (2006). Phylum Arthropoda. In: Woo, P.T.K. (ed.) (2006). Fish Diseases and Disorders, Volume 1: Protozoan and Metazoan Infections, 2nd Edition. Wallingford and CABI Publishing, pp. 466-565. Lintermans, M. (2000). The Status of Fish in the Australian Capital Territory: A Review of Current Knowledge and Management Requirements. Technical Report 15. Wildlife Research & Monitoring Branch, Environment ACT, Canberra. Lintermans, M. (2002). Fish in the Upper Murrumbidgee Catchment: A Review of Current Knowledge. Environment ACT, Canberra. 92 pp. Lintermans, M. (2007). Fishes of the Murray-Darling Basin: An introductory guide. Murray-Darling Basin Commission Publication No. 10/07. Lintermans, M. (2013). Chapter 12 - Conservation and Management. In: Humphries, P., & Walker, K. (eds.) (2013). Ecology of Australian Freshwater Fishes. CSIRO Publishing, Collingwood. pp. 283-316. Lyon, J.P., Bird, T.J., Kearns, J., Nicol, S., Tonkin, Z., Todd, C.R., O’Mahony, J., Hackett, G., Raymond, S., Lieschke, J., Kitchingman, A., & Bradshaw, C.J.A. (2019). Increased population size of fish in a lowland river following restoration of structural habitat. Ecological Applications 29(4), e01882. 10.1002/eap.1882 Longreach Leader (1944). More Fish Yarns, Fish Bite at Shadow. The Longreach Leader weekly newspaper, Queensland. Saturday 8 July 1944, p. 5. Lyon, J.P., & O’Connor, J.P. (2008). Smoke on the water: Can riverine fish populations recover following a catastrophic fire-related sediment slug? Austral Ecology 33, 794-806. Mallen-Cooper, M., Stuart, I.G., Hides-Pearson, F., & Harris, J. (1995). Fish migration in the Murray River and assessment of the Torrumbarry fishway. Final report for Natural Resource Management Strategy Project N002. NSW Fisheries Research Institute and the Cooperative Research Centre for Freshwater Ecology. Mallen-Cooper, M., & Stuart, I.G. (2003). Age, growth and non-flood recruitment of two potamodromous fishes in a large semi-arid/temperate river system. River Research and Applications 19, 697-719. Merrick, J.R. (1996). Family Terapontidae: Freshwater grunters or perches. In: McDowall, R.M. (1996). Freshwater Fishes of South-Eastern Australia. Reed Books, Chatswood, New South Wales. Mitchell, T.L. (1838). Three expeditions into the interior of eastern Australia, with descriptions of recently explored region of Australia Felix, and of the present colony of New South Wales. T. & W. Boone, London. Volume 1: 1-351. Morrongiello, J.R., Beatty, S.J., Bennett, J.C., Crook, D.A., Ikedife, D.N.E.N., Kennard, M.J., Kerezsy, A., Lintermans, M., McNeil, D.G., Pusey, B.J., & Rayner, T. (2011). Climate change and its implications for Australia’s freshwater fish. Marine and Freshwater Research 62, 1082-1098. Mount Barker Courier (MDC) (1952). Rare Catch by Local Fisherman. The Mount Barker Courier and Onkaparinga and Gumeracha Advertiser weekly newspaper, Mount Barker, South Australia. Thursday 31 January 1952, p. 8. Murray-Darling Basin Authority (MDBA) (2017). Native fish 2017 Basin Plan Evaluation, December 2017. MDBA publication no: 42/17. Murray-Darling Basin Authority, Canberra. Bidyanus bidyanus (Silver Perch) consultation Page 30 of 36

Murray-Darling Basin Authority (MDBA) (2019). Personal communication by email, 4 November 2019. Murray-Darling Basin Authority, Canberra. Nepean Times (1936). Aboriginal Notes – Primitive Method of Catching Fish. Nepean Times weekly newspaper, Penrith, New South Wales. Saturday 15 February 1936, p. 8. New South Wales Department of Primary Industries (NSW DPI) (2006). Threatened species recovery planning program - Silver Perch (Bidyanus bidyanus) NSW recovery plan. NSW Department of Primary Industries, Port Stephens, 43 pp. Nichols, S., & Gilligan, D. (2004). What about the fish? Improving fish passage through wetland flow control structures in the lower River Murray. Australian Landscape Trust, Melbourne. Ovens and Murray Advertiser (O&M Advertiser) (1882). Bright. The Ovens and Murray Advertiser weekly newspaper, Beechworth, Victoria. Saturday 21 January 1882, p. 1. Ovens and Murray Advertiser (O&M Advertiser) (1883). The Proposed Exhibition. The Ovens and Murray Advertiser weekly newspaper, Beechworth, Victoria. Saturday 25 March 1883, p. 2. Pollard, D.A., Llewellyn, L.C., & Tilzey, R.D.J. (1980). Management of freshwater fish and fisheries. In: Williams, W.D. (ed.) An Ecological Basis for Water Resource Management. Australian National University Press, Canberra. pp. 227-270. Pratt, B.H. (1979). The Canberra Fisherman. Australian National University (ANU) Press, Canberra. Raymond, S., Koehn, J., Tonkin, Z., Todd, C., Stoessel, D., Hackett, G., O’Mahony, J., Berry, K., Lyon, J., Sharley, J., & Moloney, P. (2019). Differential responses by two closely related native fishes to restoration actions. Restoration Ecology 27, 1463-1472. 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. Rhodes, J.O. (1999). Heads and tales: recollections of a fisheries and wildlife officer. The Australian Deer Research Foundation. Melbourne, Victoria. Roberts, J., Chick, A., Oswald, L., & Thompson, P. (1995). Effects of carp, Cyprinus carpio, an exotic benthivorous fish, on aquatic plants and water quality in experimental ponds. Marine and Freshwater Research 46, 1171-1180. Roberts, J., & Sainty, G. (1996). Listening to the Lachlan. Geoff Sainty and Associates, Potts Point, NSW. Rolls, R. (2005). Patterns in fish communities in the presence and absence of carp (Cyprinus carpio) in slope and upland regions of the Murray–Darling Basin. B.Sc.(Honours) Thesis, Charles Sturt University, Wagga Wagga, NSW, Australia. Rowland, S.J., & Allan, G.L. (1994). Development of Techniques for the Commercial Aquaculture of the Freshwater Fish Silver Perch (Bidyanus bidyanus). Final Report to the Fisheries Research and Development Corporation, Project No. 90/71. pp. 76. Rowland, S.J., & Ingram, B.A. (1991). Diseases of Australian native freshwater fishes with particular emphasis on the ectoparasitic and fungal diseases of Murray cod (Maccullochella peeli), golden perch (Macquaria ambigua) and silver perch (Bidyanus bidyanus). Fisheries Bulletin 4, July 1991, NSW Fisheries, Sydney, NSW, Australia. Shearer, K.D., & Mulley, J.C. (1978). The introduction and distribution of the carp, Cyprinus carpio Linnaeus, in Australia. Australian Journal of Marine and Freshwater Research 29, 551-63. Shepparton News (2017). Monitoring reveals fish numbers rising. Shepparton News website, 12 May 2017, source: https://www.sheppnews.com.au/2017/05/12/88390/monitoring- reveals-fish-numbers-rising

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Sydney Mail (1874). Bound West – Parkes to Forbes. The Sydney Mail and New South Wales Advertiser weekly magazine, Sydney, New South Wales. Saturday 26 September 1874, p. 407. Sydney Mail (1904). Fishing. The Sydney Mail and New South Wales Advertiser weekly magazine, New South Wales. Wednesday 29 June 1904, p. 1654. Sydney Morning Herald (SMH) (1859). Wellington. Sydney Morning Herald daily newspaper, Sydney, New South Wales. Friday 9 December 1859, p. 3. The Age (1920). Omeo. The Age daily newspaper, Melbourne, Victoria. Tuesday 21 September 1920, p. 9. The Argus (1908a). Nature Notes and Queries. The Argus daily newspaper, Melbourne, Victoria. Friday 15 May 1908, p. 9. The Argus (1908b). Nature Notes and Queries. The Argus daily newspaper, Melbourne, Victoria. Friday 20 November 1908, p. 7. The Australasian (1873). Fishing and Shooting Notes on the Goulburn. The Australasian weekly newspaper, Melbourne, Victoria. Saturday 5 April 1873, p. 12. The Critic (1904). Pages from a Swagman’s Diary. The Critic weekly magazine, Adelaide, South Australia. Wednesday 18 May 1904, p. 13. The Telegraph (1921). Nile of Australia: Naturalists on the Murray. The Telegraph daily newspaper, Brisbane, Queensland. Saturday 16 April 1921. p. 14. The Queenslander (1867). News of the Week. The Queenslander weekly newspaper, Brisbane, Queensland. Saturday 9 February 1867, p. 5. Threatened Species Scientific Committee (TSSC) (2013). Conservation Advice Bidyanus bidyanus (silver perch). Commonwealth Threatened Species Scientific Committee Canberra, Department of the Environment. Available online at http://www.environment.gov.au/biodiversity/threatened/species/pubs/76155-conservation- advice.pdf Tonkin, Z.D., Humphries, P., & Pridmore, P.A. (2006). Ontogeny of feeding in two native and one alien fish species from the Murray-Darling Basin, Australia. Environmental Biology of Fishes 76, 303 – 315. Tonkin, Z., King, A., Mahoney, J., & Morrongiello, J. (2007). Diel and spatial drifting patterns of silver perch Bidyanus bidyanus eggs in an Australian lowland river. Journal of Fish Biology 70, 313-317. Tonkin, Z., Stuart, I., Kitchingman, A., Jones, M., Thiem, J., Zampatti, B., Hackett, G., Koster, W., & Koehn, J. (2017). The effects of flow on silver perch population dynamics in the Murray River. Arthur Rylah Institute for Environmental Research. Technical Report Series No. 282. Victoria State Government Department of Environment, Land, Water and Planning Heidelberg, Victoria. Trueman, W.T. (2011). True Tales of the Trout Cod. River Histories of the Murray-Darling Basin. Murray-Darling Basin Authority Publication No. 215/11. Murray-Darling Basin Authority, Canberra. Vertessy, R., Barma, D., Baumgartner, L., Mitrovic, S., Sheldon, F., & Bond, N. (2019). Final report of the Independent Assessment of the 2018-19 fish deaths in the lower Darling. Report written by Independent Panel for the Australian Government. Available online at https://www.mdba.gov.au/publications/mdba-reports/independent-panel-assess-fish- deaths-lower-darling Victorian Department of Environment, Land, Water and Planning (Vic DELWP) (2018). Delivering Water for Victoria Progress Report. The State of Victoria Department of Environment, Land, Water and Planning. Bidyanus bidyanus (Silver Perch) consultation Page 32 of 36

Vilizzi, L., Thwaites, L.A., Smith, B.B., Nicol, J.M., & Madden, C.P. (2014). Ecological effects of common carp (Cyprinus carpio) in a semi-arid floodplain wetland. Marine and Freshwater Research 65, 802-817. Walker, K.F. (1985). A Review of the Ecological Effects of River Regulation in Australia. Hydrobiologia 125, 111-129. Warwick Daily News (1937). Golden Carp. Letter to the Editor, Warwick Daily News daily newspaper, Queensland. Saturday 8 May 1937, p. 6. Wharton, J.C.F. (1971). European carp in Victoria. Fur, Feathers and Fins 130, 3-11. Yackandandah Times (1917). A Trip to Tawonga. The Yackandandah Times weekly newspaper, Yackandandah, Victoria. Thursday 4 January 1917, p. 2. Zampatti, B.P., Strawbridge, A., Thiem, J., Tonkin, Z., Maas, R., Woodhead, J., & Fredberg, J. (2018). Golden perch (Macquaria ambigua) and silver perch (Bidyanus bidyanus) age demographics, natal origin and migration history in the River Murray, Australia. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2018/000116-1. SARDI Research Report Series No. 993. 64 pp.

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Collective list of questions for Silver Perch (Bidyanus bidyanus) – your views

SECTION A GENERAL

1. Provide a general summary of your views on the eligibility of Silver Perch across its entire national extent for inclusion on the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) threatened species list in the Endangered, or any other, category. If you consider the species to be eligible for threatened species listing, detail what you think are the necessary conservation actions.

2. Can you provide additional data or information relevant to the assessment, especially any collected in recent years?

PART 1 – INFORMATION TO ASSIST LISTING ASSESSMENT

SECTION B DO YOU HAVE ADDITIONAL INFORMATION ON THE ECOLOGY OR BIOLOGY OF THE SPECIES?

Biological and taxonomic information

3. Can you provide any additional or alternative information or estimates for the Silver Perch’s longevity (27 years in Cataract Dam, 17 years in the Murray-Darling Basin), age-at-maturity (males – three years, females – five years) and generation length (12 years) with supporting references? If you consider that the Cataract Dam estimate is inappropriate for using in estimates of generation length, please provide the scientific logic for doing so, along with referenced information to support your stance.

4. Do you have any additional information regarding the ecology or biology of the species not in the current assessment?

SECTION C ARE YOU AWARE OF THE STATUS OF THE TOTAL POPULATION OF THE SPECIES?

Population size

5. Can you provide estimates of the current population size of mature adults in the natural, self-sustaining population occurring in the middle-Murray River? Importantly, for the purposes of the assessment against the listing criteria, is it likely that the population is greater or less than 10 000 individuals? Please provide any supporting justification or other information.

SECTION D ARE YOU AWARE OF TRENDS IN THE OVERALL POPULATION OF THE SPECIES?

Evidence of total population size change

6. Does the estimated rate of decline over the past 36 years used in the assessment seem reasonable? If not, please provide justification of your response including supporting references.

7. Please provide additional evidence which shows any population is stable, increasing or declining.

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SECTION E ARE YOU AWARE OF INFORMATION ON THE TOTAL RANGE OF THE SPECIES?

Current Distribution/range/extent of occurrence, area of occupancy

8. Do you agree with the estimates of the current extent of occurrence (EOO) and area of occupancy (AOO) in the advice (see under Criterion 2 (page 11) and Figure 1 (page 15))? If not, can you provide an alternative estimate with supporting information?

9. Is the distribution described in the assessment accurate? If not, please provide justification for your response and provide supporting information.

SECTION F ARE YOU AWARE OF TRENDS IN THE TOTAL RANGE OF THE SPECIES?

Past Distribution/range/extent of occurrence, area of occupancy

10. Do you consider that the way the historic distribution of the Silver Perch has been estimated is appropriate? Please provide justification for your response.

11. Can you provide estimates of historic EOO and AOO for Silver Perch across its former range for the 1.) national extent, and 2. Murray-Darling Basin? Please provide justification for your response.

PART 2 – INFORMATION FOR CONSERVATION ADVICE ON THREATS AND CONSERVATION ACTIONS

SECTION G DO YOU HAVE INFORMATION ON THREATS TO THE SURVIVAL OF THE SPECIES?

12. Do you consider that all threats to Silver Perch have been identified and described adequately?

a. Competition and predation by the invasive introduced fish species, European Carp (Cyprinus carpio) and Redfin (Perca fluviatilis). b. Habitat loss and fragmentation caused by barriers to movement. c. Altered flow regime due to water storage, diversion and extraction. d. Disease and parasites such as Epizootic Haematopoietic Necrosis Virus and parasitic invertebrates.

13. Can you provide additional or alternative information on threats, past, current or potential that may adversely affect Silver Perch at any stage of its life cycle, with supporting references?

SECTION H DO YOU HAVE INFORMATION ON CURRENT OR FUTURE MANAGEMENT FOR THE RECOVERY OF THE SPECIES?

14. a. What planning, management and recovery actions are currently in place supporting protection and recovery of Silver Perch?

b. To what extent have they been effective?

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15. Can you recommend any additional or alternative specific threat abatement or conservation actions that would aid the protection and recovery of Silver Perch?

SECTION I DO YOU HAVE INFORMATION ON STAKEHOLDERS IN THE RECOVERY OF THE SPECIES?

16. a. Are you aware of other knowledge (e.g. traditional ecological knowledge) or individuals/groups with knowledge that may help better understand population trends/fluctuations, or critical areas of habitat for Silver Perch?

b. Are you aware of any cultural or social importance or use that Silver Perch has?

17. What individuals or organisations are currently, or potentially could be, involved in management and recovery of Silver Perch?

18. How aware of the Silver Perch are land managers where it is found?

PART 3 – ANY OTHER INFORMATION

19. Do you have comments on any other matters relevant to the assessment of Silver Perch?

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