Marron cainii (Austin) in Victoria – a Literature Review

David Bryant and Phil Papas

2007

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167

Marron (Austin) in Victoria – a literature review

David Bryant and Phil Papas

Arthur Rylah Institute for Environmental Research 123 Brown Street, Heidelberg, Victoria 3084

November 2007

Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment. Heidelberg, Victoria.

Report produced by: Arthur Rylah Institute for Environmental Research Department of Sustainability and Environment PO Box 137 Heidelberg, Victoria 3084 Phone (03) 9450 8600 Website: www.dse.vic.gov.au/ari

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Citation

Bryant, D. and Papas, P. (2007). ‘Marron Cherax cainii (Austin) in Victoria – a literature review’. Arthur Rylah Institute for Environmental Research Technical Report Series No. 167. (Department of Sustainability and Environment: Heidelberg).

ISBN 978-1-74208-219-6 (Print) ISBN 978-1-74208-220-2 (Online) ISSN 1835-3827 (Print) ISSN 1835-3835 (Online)

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Contents

List of figures and tables...... ii Acknowledgements...... iii Summary ...... iv 1 Introduction ...... 1 2 Biology and ecology of marron...... 1 2.1 ...... 1 2.2 Habitat...... 2 2.3 Biology...... 2 2.4 Environmental tolerances ...... 4 3 Marron translocations...... 7 3.1 Translocations outside Victoria...... 7 3.2 Translocations within Victoria...... 8 3.2.1 History of marron in Victoria ...... 8 3.2.2 Known and established populations...... 9 3.2.3 Unconfirmed populations following reports of marron...... 10 3.2.4 Other known occurrences of marron in Victoria ...... 11 3.2.5 Summary of marron observations in Victoria...... 11 4 Potential distribution of marron...... 12 4.1 Predicting the potential distribution of marron ...... 12 4.2 The potential distribution of redclaw within Victoria ...... 13 5 Potential impacts of marron in Victoria...... 14 5.1 Disease ...... 14 5.2 Competitive interactions between ...... 14 6 Knowledge gaps and future considerations...... 16 6.1 Predicting the potential spread of marron in Victoria ...... 16 6.2 Presence of marron in private waters ...... 16 6.3 The impact of marron on endemic crayfish ...... 16 7 References...... 17 Appendix 1. Climex climactic matching...... 20

i

List of figures and tables Figure 1. Marron (Cherax cainii) characters for identification, from Fisheries Western (2004)...... 3

Figure 2. Yabby (Cherax destructor/albidus) characters for identification, from Fisheries WA (2004)...... 4 Figure 3. Map showing distribution of marron in (courtesy of Fisheries Western Australia)...... 8 Figure 4. Confirmed marron populations on the Mornington Peninsula, southeast of Melbourne...... 10

Figure 5. Timeline of marron observations in Victoria...... 11 Figure 6. The area of Australia potentially suitable for marron farming (from Lawrence (1998)). Note that the claim that marron farming is not permitted in Victoria is not accurate. If the proposed activity is consistent with NAS policy statement, an aquaculture licence and NAS permit can be issued for farming of marron (Paul Mainey, Fisheries Victoria, pers. comm. 2007)...... 12

Figure 7. Climate zones of Australia (from the Bureau of Meteorology)...... 12 Figure 8. Current production area for redclaw (Cherax quadricarinatus) within Australia (from Jones (1998))...... 13

Table 1. Environmental tolerances for marron (Cherax cainii)...... 5 Table 2. Environmental tolerances for the yabby (Cherax destructor/albidus) and redclaw (Cherax quadricarinatus)...... 6 Table 3. Summary of the environmental tolerances for the marron (Cherax cainii), the yabby (Cherax destructor/albidus) and redclaw (Cherax quadricarinatus). Values are the means from tables 1 and 2...... 7

ii

Acknowledgements Funding for the review was provided by Melbourne Water. The following people are thanked for their comments on the draft: Louise Galli (Fisheries Victoria, Department of Primary Industries), Paul Mainey (Fisheries Victoria, Department of Primary Industries), Bill O’Connor (Biodiversity and Ecosystem Services, Department of Sustainability and Environment), Vin Pettigrove (Melbourne Water), Tarmo Raadik (Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment), Ed Tsyrlin (Melbourne water) and Matt Ward (Fisheries Victoria, Department of Primary Industries).

iii

Summary Marron (Cherax cainii), a freshwater crayfish endemic to Western Australia, is a declared noxious species within Victoria. The species has been translocated into Victoria with two self sustaining populations known on the Mornington Peninsula, southeast of Melbourne. Both populations occur in artificial waterbodies – Devilbend reservoir and OT Dam. It is suspected that attempts to translocate marron sourced from these populations have been made. The true extent of the marron population in Victoria is unknown as private waters (farm dams for example) have not been surveyed.

Tolerance data for marron indicate that the spread of marron in Victoria would not be constrained by water temperature. The impact of marron on native freshwater crayfish in Victoria is unknown. Further study on the distribution of marron in Victoria, its physiological tolerances under Victorian conditions and its interaction with native freshwater crayfish is required before an adequate assessment of the impact of the species on the freshwater ecology of Victorian waters can be confidently ascertained.

iv Marron Cherax cainii (Austin) in Victoria – a literature review

1 Introduction Marron, Cherax cainii (Austin 2002), formerly (Smith 1912) are endemic to the south-west of Western Australia (WA). In recent times, its distribution in Australia has been widely extended by the commercial aquaculture and recreational fishing industries in WA (Morrissy 1978, Horwitz 1990b, Arthington and McKenzie 1997); the aquaculture industry in (Zeidler 2000), Queensland and New South Wales (Merrick and Lambert 1991); and aquaculture overseas (Smith 1988), Avenant-Oldewage 1993). There have been several unconfirmed reports of marron in Victoria over the past 30 years. The only survey conducted specifically to establish the presence of marron in Victoria was undertaken in 1996-1997 by the Freshwater Ecology Section of the Arthur Rylah Institute (ARI) in response to a report of marron on and near the Mornington Peninsula. Two populations of marron were confirmed in that region: Devilbend Reservoir and OT Dam. Little attention has been given to the presence of marron in Victoria since the initial survey. Marron were declared noxious in Victoria in 1986 due to concerns they may become established in Victorian waters, impacting on local biota and introducing novel disease organisms not present at the time in Victoria (Victorian Fisheries Notes 1988). Overseas examples of exotic crayfish establishment are numerous including reporting of local extinctions and population decline of endemic crayfish (Hill and Lodge 1999, Usio et al. 2001), hence the concern would seem justified. This literature review compiles information on the distribution of marron in Victoria, investigates the likelihood of its further spread using climatic modeling and investigates the impacts of such a spread on other freshwater biota. Knowledge gaps in these areas are identified. Issues raised in this review may also be applicable to another Cherax species, Cherax quadricarinatus, commonly referred to as redclaw, which is briefly covered in the review.

2 Biology and ecology of marron 2.1 Taxonomy Marron can be readily distinguished from other Cherax species by the presence of five keels on the dorsal surface of their head and two small spines on the telson (Figure 1). Yabbies (Cherax destructor/albidus), the other Cherax species within Victoria, in contrast have four keels along the head with only two easily discernible, no spines on the telson and have elongate and large chelipeds (Figure 2). There are two discrete forms of marron, a smooth form and hairy form. They were considered to be sub species (Austin and Knott 1996) until 2002 when allozyme evidence indicated these forms were distinct species (Austin and Ryan 2002). The hairy form, restricted to the Margaret River system in WA, maintained the name Cherax tenuimanus (Smith), while the smooth and widely translocated form was given the name Cherax cainii (Austin). This name change is being disputed and is currently before the International Commission on Zoological Nomenclature (Case No. 3267). The Victorian populations are both assumed to be Cherax cainii based on the results of

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 1 Marron Cherax cainii (Austin) in Victoria – a literature review

DNA analysis of marron from the Mornington Peninsula, reported by Nguyen et al. (2002). Described only as being from an inundated quarry near Arthur’s Seat State Park it is assumed the marron sourced for analysis were from Devilbend Reservoir. As such, unless stated otherwise ‘marron’ in this review refers to Cherax cainii.

2.2 Habitat In their natural environment, marron inhabit the clear, deep water reaches of permanently flowing rivers (Merrick and Lambert 1991, Mosig 1998, Wingfield 1998), preferring sandy reaches with structure (e.g. snags and rocks) for shelter (Molony et al. 2004). Marron are not considered to be burrowers but do excavate short unbranched burrows under structures (Clunie et al. 2002). Mosig (1998) however, reports that burrowing may occur in the banks of dams where refuge habitat is limiting. In Devilbend Reservoir, marron have been observed using multi entranced burrows in soft mud banks and under timber debris (T. Raadik, Department of Sustainability and Environment, pers.comm. 2006). Marron farming has proven to be extremely successful in clay bottomed farm dams and aquaculture ponds (Morrissy 1976, Fisheries and Wildlife 1977, Morrissy et al. 1990, Merrick and Lambert 1991, Lawrence 1998, Mosig 1998, Wingfield 1998). Habitat in the form of tyres, rope fibre, piping or other materials is often added to the dams to provide refuge. In natural waters where marron have been translocated, they have been successful in streams that are seasonally reduced to isolated pools with large fluctuations in turbidity (Mosig 1998). Marron are predated upon by cormorants, water rats, tortoises and fish (Mosig 1998, Tay et al. 2007). They are also subject to cannibalism by larger marron (Merrick and Lambert 1991), making the availability of refuge habitat is especially important for young individuals.

2.3 Biology The biology and behavior of marron is largely similar to the yabbie and well documented (e.g. Mosig 1998, Merrick and Lambert 1991). This review does not attempt to incorporate all this information, rather a brief overview of biology and behaviour is provided. Marron are the third largest freshwater crayfish species in the world and largest Cherax species, reaching a length of 380 mm and weighing up to 2.7 kg (Merrick and Lambert 1991, Molony et al. 2004). Maturity under favorable conditions can be reached in two years, although is commonly three years (Merrick and Lambert 1991). Breeding occurs annually in spring, triggered by water temperature and day length (Mosig 1998). Females have been reported to carry between 95 and 900 berries (Merrick and Lambert 1991) but generally average 150 (Mosig 1998). Growth rate and early development is similar to the yabbie with marron continuing to grow well beyond that for the yabbie.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 2 Marron Cherax cainii (Austin) in Victoria – a literature review

a

b c

Figure 1. Marron (Cherax cainii) characters for identification, from Fisheries Western Australia (2004). a) Five keels along their head, b) two small spines on the telson, and c) narrow, pincer- like chelipeds.

In order to reduce the risk of predation, greatest activity is observed at night when marron commonly move to shallower water to feed (Merrick and Lambert 1991). During daylight hours marron seek refuge under available habitat or in deeper water (Merrick and L ambert 1991, Mosig 1998). Marron are opportunistic feeders, consuming largely plant material but also carrion and small where available (Merrick and Lambert 1991). Mosig (1998) reports “they will eat just about anything you put in front of them”. Beatty (2006) demonstrated in the Hutt River in WA that marron assimilated mostly matter in the form of the exotic fish, Gambusia holbrooki, abundant in the river system. In reference to aquaculture ponds, Lawrence (1998) reports that ponds should have a perimeter fence to stop marron crawling out and water rats or other predators from getting in. This infers that marron are capable of moving across land to some degree in search of other waters. This behavior is known in other freshwater crays including species of Euastacus and yabbies and as such would not be unexpected (Tarmo Raadik, Department of Sustainability and Environment, pers. com. 2007).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 3 Marron Cherax cainii (Austin) in Victoria – a literature review

a

b c

Figure 2. Yabby (Cherax destructor/albidus) characters for identification, from Fisheries WA (2004). a) Four keels on head but only two obvious, b) no spines on the telson, c) chelipeds elongated and quite large.

2.4 Environmental tolerances The interest in marron for aquaculture purposes has led to their environmental tolerances to basic physico-chemical water parameters being relatively well known under aquaculture conditions. No tolerance data was found relating to specific conditions in the natural environment. Tolerance data presented in this review is for aquaculture conditions and as such may not accurately represent tolerances in natural waters. Tolerance data is likely to provide an accurate prediction of the likely success of a marron population at any particular site. This will be particularly true for artificial water bodies from which the tolerance data was derived. Using tolerance data to predict habitat suitability over a broader spatial scale is limited due to the variability in physico- chemical parameters between different waterbodies and reaches, even within the same region.

Marron have a greater tolerance to salinity than the yabby (Cherax destructor/albidus) and redclaw (Cherax quadricarinatus) (Table 1 and 3). This may be due to Western Australia’s comparatively high natural (background) salinity concentrations. Their endemic home range occurs within flowing water (i.e. typically higher oxygen levels) habitat, which may explain why they have the least tolerance to low dissolved oxygen concentrations of the three species. Like members of Euastacus, marron have been observed to leave unfavorable conditions by physically removing themselves from the water (Morrissy 1978).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 4 Marron Cherax cainii (Austin) in Victoria – a literature review

Marron is the cooler climate species of the three, having a lower optimal temperature of 17.5°C and an upper optimal temperature of 24.5°C (Table 3). Morrissy (1990) reports water temperature extremes of 8 and 26oC in the central part of the marron’s natural distribution, where its abundance is highest. Survival for short periods (50% survival over 2 – 3 days) at temperatures as low as 4oC has however been stated (D, Sampey, Marron Growers Association, WA, pers.comm. 2007). In contrast, redclaw, endemic to northern Queensland and the north of the Northern Territory (Jones 1990), tolerate high water temperatures and lower oxygen levels (Table 2 and 3). The yabby displays the greatest tolerance range (Table 2) of the two southern species (marron and yabby (Table 3)) attributing to the success of the Yabby in aquaculture across Australia.

Table 1. Environmental tolerances for marron (Cherax cainii).

Dissolved pH Water Temperature (oC) Salinity (ppm) Oxygen (ppm) Source of informatiom optimal distress death Low High optimal Min Min for growth Max for growth Growth impaired Max Max (Shipway 6.5 2.0 0.9 1951) (Lawrence >6000- 6 3 7 8.5 30 12.5 24 15000 1998) 8000 (Morrissy et 12- 30 24 al. 1990) 13 Merrick and Lambert ≥6 7 8 17-25 17000 (1991) Fisheries >6 25 31 17000 NSW (2006) Mossig >6 18-24 (1998) 4 (for D. Sampey, short Marron periods, Growers 2-3 days, Association, 18-24 50% 26 12 WA survival) (pers.comm, 8 (for 2007) prolonged periods) 8 26 Morrissy (Exposure (Exposure

(1990) in in endemic endemic range) range) 17.5- Mean >6 2.5 0.9 7 8.25 >4 28.6 12.3 24 7000 16333 24.5

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 5 Marron Cherax cainii (Austin) in Victoria – a literature review

Table 2. Environmental tolerances for the yabby (Cherax destructor/albidus) and redclaw (Cherax quadricarinatus).

Dissolved Oxygen pH Water Temperature (oC) Salinity (ppm) (ppm)

Source of information optimal distress Low High optimal Min Max Min for growth Stress Growth impaired Max death Morrissy et al 6000- 14000- Yabby 15 22000 .(1990) 8000 15000 Merrick and 25- Lambert ≥4 7.5 8.5 >6000 28 (1991) Mills (1983) 28 15 34 >5000 16000 20- Mosig (1998) 6 9 1 35 26 Fisheries NSW 22- >4 7.5 10.5 1 36 15 17000 25000 (2005) 28 Yabbie Growers 5-7 2 7 7.5 Association (1992) 22- Mean 5 2 7 8.9 1 35.5 15 34 6000 15750 21000 27.5 23- Redclaw Jones (1998) 10 36 31 Merrick and Lambert 6.5 8 (1991) 23- Mosig (1998) >5 1 10 35 12000 18000 28 Fisheries NSW 28 34 17000 (2005) 20- Jones (1990) 18000 34 22- Mean >5 1 6.5 8 10 35.5 34 12000 18000 31

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 6 Marron Cherax cainii (Austin) in Victoria – a literature review

Table 3. Summary of the environmental tolerances for the marron (Cherax cainii), the yabby (Cherax destructor/albidus) and redclaw (Cherax quadricarinatus). Values are the means from tables 1 and 2.

Dissolved Oxygen pH Water Temperature (oC) Salinity (ppm) (ppm) optimal optimal distress death Low High Lower Upper Min Max Min for growth Max for growth Stress Growth impaired Max death

>6 2.5 0.9 6.8 8 17.5 24.5 8 28.6 12.5 24 7000 17250 Marron Yabby 5 2 7 8.9 22 27.5 1 35.5 15 34 6000 15750 21000

>5 1 6.5 8 22 31 10 35.5 12000 18000 Redclaw

Key Lowest tolerance of the three species Intermediate tolerance of the three species Highest tolerance of the three species Insufficient data to draw comparisons

3 Marron translocations 3.1 Translocations outside Victoria International and domestic interest in marron farming has seen marron translocated domestically and internationally. Marron farming has been trialed with varying success in Queensland (Jones 1990, Merrick and Lambert 1991, Mosig 1998), New South Wales (Merrick and Lambert 1991) and South Australia (Lawrence 1988, Mosig 1998, Zeidler 2000). Overseas, marron have been translocated to America (Merrick and Lambert 1991, Lawrence and Morrissy 2000), South Africa (Avenant-Oldewage 1993, Lawrence and Morrissy 2000), New Zealand (McDowall 1988), Japan, Zimbabwe, China, Chile and the Caribbean (Lawrence and Morrissy 2000). Initial translocation of marron within Australia occurred in WA (Figure 3) where its range was extended as far as the Chapman River, north of Geraldton (Morrissy 1978), Esperance in the east (Merrick and Lambert 1991) and as far inland as Kalgoorlie (Fisheries and Wildlife 1977).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 7 Marron Cherax cainii (Austin) in Victoria – a literature review

Figure 3. Map showing distribution of marron in Western Australia (courtesy of Fisheries Western Australia).

Jones (1990) reports the introduction of marron into southeast Queensland in 1979. Marron farming expanded in the area until 1986 when a particularly hot summer resulted in water temperatures exceeding the lethal limit for the species, resulting in mass mortality. Similarly, marron introduced into northeastern NSW, also suffered high mortality in the same summer (Fisheries NSW). Redclaw has since largely replaced marron in this area due to its tolerance of higher water temperatures. Marron were introduced onto Kangaroo Island, South Australia (SA) in the early 1980’s. They quickly became established in the natural waterways and now reside in many of the permanent waters on the island (Zeidler 2000).

3.2 Translocations within Victoria

3.2.1 History of marron in Victoria Documented information on the presence of marron in Victoria is scarce. The earliest documents sourced are applications for fish culture permits for marron, one submitted in 1978 (Narracan, Gippsland) and the other 1982 (Kangaroo Ground, outer Melbourne) – both applications were refused. Reference to the ‘probable’ presence of marron in Victoria was made in 1987 in a letter published in the Austasia Aquaculture Magazine. The letter referred to the inspection of several dams in the Stawell area for marron by Fisheries Inspectors and Police (Tayler 1988).

In 1996, a verbal report by a member of the public, Ben Scullun (Ben Scullun, pers. comm. 2007), was made to the Arthur Rylah Institute, inferring marron were present in waterways on the Mornington Peninsula (T. Raadik, Department of Sustainability and Environment pers. comm. 2007) including Devilbend Reservoir and OT Dam. A survey following up on this report led to the first documented presence of marron in Victorian

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 8 Marron Cherax cainii (Austin) in Victoria – a literature review waters. The only other marron specimen known from Victorian waters was handed in by a fisherman in the south-west of the state to the Department of Sustainability and Environment and later identified to be Cherax cainii (Chris Austin, Charles Darwin University, pers. comm. 2007).This specimen was reported as being caught in the Merri River at Warnambool.

3.2.2 Known and established populations

Devilbend Reservoir Devilbend Reservoir is located on the Mornington Peninsula, between Mount Martha on Port Phillip Bay and Hastings on Western Port Bay (Figure 4). The reservoir was constructed in 1964 and primarily served as a backup supply of drinking water for the Mornington Peninsula during peak summer demand (Melbourne Water 2000). The Reservoir was decommissioned in 2000 as a consequence of an upgrade of Melbourne Water’s supply system on the Mornington Peninsula (Melbourne Water 2001). The reservoir has a surface area of 3 km2 with water depth ranging from a 3 m fringing ledge to a main body of 10-20 m (McGuckin 2001). It has a capacity of 14,600 ML (Department of Water Resources 1989). After extensive consultation between Melbourne Water, the public, and government authorities, it was decided that the reservoir and the surrounding land, 1057 hectares in total, would be maintained as public parkland following decommissioning. Parks Victoria assumed management of the area in March 2007 and is currently finalizing a management plan for the area (due in mid 2008).

Two surveys have confirmed the presence of marron within the Reservoir. The first was conducted in 1996-1997 by the Freshwater Ecology group of the Arthur Rylah Institute using spot-lighting and electrofishing techniques (O’Connor 1997). The second, undertaken in October 2001, was a fish survey conducted as part of the decommissioning process (McGuckin 2001). In both surveys, Cherax cainii was the only crayfish species recorded in Devilbend Reservoir although weir keepers claim Cherax destructor/albidus was present in earlier years (O’Connor 1997). Public access to the Reservoir is currently restricted and fishing is not permitted.

OT Dam O.T. Dam is situated within the Arthur’s Seat State Park between Dromana and Red Hill (Figure 4) and managed by Parks Victoria. The dam was constructed in 1922 by OT Cordial to provide water for fruit tree irrigation. The dam is comprised of a 12.5 m high, 115 m long, earth-fill embankment and has a capacity of 75 ML (B. Brinkman, Parks Victoria, pers. comm., 2007). The dam no longer serves any commercial function and is accessible by walkers and management vehicles only. The presence of marron in O.T. Dam was confirmed on the 1996–1997 survey by ARI when both marron and yabbies were recorded (O’Connor 1997). It is suggested marron were introduced into OT Dam around the same time as they were into Devilbend Reservoir, sometime in the 1970’s (pers. comm. A. Kidd, Parks Victoria, 2007). Fishing within the dam is permitted with and abiding by a current Recreational Fishing License.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 9 Marron Cherax cainii (Austin) in Victoria – a literature review

Devilbend Reservoir

OT Dam

Figure 4. Confirmed marron populations on the Mornington Peninsula, southeast of Melbourne.

3.2.3 Unconfirmed populations following reports of marron

French Island The following information was derived from email correspondence between Fisheries Victoria and ARI. In late 2000, information was received by Fisheries Victoria that marron had been stocked into dams on French Island. In response, Fisheries Victoria, in conjunction with Parks Victoria, and after consultation with ARI, conducted a survey of nine dams using opera house and drop nets to determine the validity of these claims. Yabbies were caught in three of the nine dams with no marron recorded in the survey. No further trapping was conducted and it was concluded that marron were not present. Discussions with French Island residents during the time of the survey revealed that some locals referred to large blue yabbies as marron, while others refer to them as “Queensland Blues”. This may possibly explain the initial report of marron to Fisheries Victoria. It should be noted that the opera house nets were set and collected in daylight hours, while marron are known to be most active at night. Marron are also harder to coax into nets than yabbies, not responding as well to conventional baits (B. Scullen pers. comm., 2007).

Merri River A crayfish reported as being captured in 2000 at Bromfield Street Weir, on the Merri River in Warnambool, was confirmed by Chris Austin (Charles Darwin University) to be C. cainii. The specimen, caught by a fisherman was submitted to the local Department of Sustainability and Environment for identification and is now lodged with the Museum of Victoria. Further sampling by Chris Austin subsequent to the capture failed to record any other specimens, although a Glenelg Spiny Freshwater Crayfish (Euastacus bispinosis) was captured at the site (Chris Austin, Charles Darwin University, pers. comm. 2007). The capture of two non-endemic crayfish at this site in 2000 would suggest there was an

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 10 Marron Cherax cainii (Austin) in Victoria – a literature review attempt to establish crayfish in this area at the time. No further specimens of Cherax cainii are known to have been recorded in the area and it is assumed the species did not become established at the site.

3.2.4 Other known occurrences of marron in Victoria

Restaurants Fisheries Victoria recently intercepted an import of live marron intended for the restaurant trade. A newspaper reported in late 2006 (Dubecki 2006) that the import was destined for two Melbourne restaurants, and was seized under the Fisheries Act. At the time of writing this report, Fisheries Victoria’s policy position changed such that permits can now be issued for the restaurant trade of live marron (Paul Mainey, Fisheries Victoria, pers. comm. 2007).

3.2.5 Summary of marron observations in Victoria Marron observations in Victoria date back to the late 1970’s (Figure 8). Confirmation of their establishment was not officially made until 1996 after the verbal report was followed up by ARI. Public access restrictions to the established populations have been their management to date.

1978 • Application for marron farming permit received from Narracan, Gippsland and refused by Fisheries and Wildlife. • Suspected time frame for introduction of marron into Devilbend Reservoir and OT Dam. 1982 Application for marron farming permit received and refused (Kangaroo Ground, outer Melbourne).

1986 Marron declared noxious by Fisheries Department.

1987 Inspection of dams in Stawell area for marron by Fisheries inspectors.

Verbal report of marron on and around the Mornington Peninsula made to ARI.

1996 Survey undertaken by ARI for marron on and around the Mornington Peninsula. Two populations confirmed on the Mornington Peninsula. 1996-1997 • Devilbend Reference Group formed to discuss future use of Devilbend 2000 Reservoir. Marron an item for discussion. • Marron reported from Merri River in the southwest of Victoria. 2001 • Melbourne Water contract a fish survey of Devilbend and Bittern reservoirs as part of decommissioning process. • Report of marron on French Island received. Survey performed with no marron recorded.

• Parks Victoria take over management of Devilbend Reservoir and surrounding land. 2007 Management plan for Devilbend Reservoir and surrounding parkland. 2008

Figure 5. Timeline of marron observations in Victoria.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 11 Marron Cherax cainii (Austin) in Victoria – a literature review

4 Potential distribution of marron 4.1 Predicting the potential distribution of marron Lawrence (1998) predicted the area of Australia potentially suitable for marron farming (Figure 6). The predicted range covers approximately the southern half of the eastern band of New South Wales, the southern half of Victoria and the eastern coastal band of South Australia. Based on air temperature the predicted range is, not surprisingly, similar to climatic zone maps of Australia (Figure 7). The range was not extended further north along the east coast due to aquaculture failures in this area (C. Lawrence, Fisheries Western Australia, pers. comm. 2007).

Figure 6. The area of Australia potentially suitable for marron farming (from Lawrence (1998)). Note that the claim that marron farming is not permitted in Victoria is not accurate. If the proposed activity is consistent with NAS policy statement, an aquaculture licence and NAS permit can be issued for farming of marron (Paul Mainey, Fisheries Victoria, pers. comm. 2007).

Figure 7. Climate zones of Australia (from the Bureau of Meteorology).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 12 Marron Cherax cainii (Austin) in Victoria – a literature review

The minimum water temperature tolerance of marron (Table 1) is likely to exclude marron from colonizing the higher altitude and smaller lowland streams in Victoria. The majority of studies relating to water temperature tolerances of marron has been performed in Western Australia, where the focus has been on upper tolerance levels. Hence, caution is needed when extrapolating this information to Victorian conditions. Accurate determination of the marron’s lower temperature threshold is yet to be determined and is an area for further research. Climate matching using CLIMEX software (Sutherst et al. 1999) was performed to identify areas with suitable environmental conditions for marron in Victoria (see Appendix). Based on the matching of air temperature, CLIMEX not unexpectedly predicted a range very similar to that illustrated by Lawrence (1998). The relationship between air temperature and water temperature has previously been shown to be weak (Hawkins et al. 1995) and as such predicted ranges must be treated with caution. This was also reported by Koehn (2004) who used CLIMEX to predict the potential spread of Carp (Cyprinus carpio) in Australia. As previously stated, mapping water temperature extremes may provide a more useful picture but was beyond this review.

4.2 The potential distribution of redclaw within Victoria Current redclaw production is restricted to northern Western Australia, the Northern Territory, Queensland and the north eastern part of NSW (Figure 8). Sites chosen for CLIMEX climatic matching north of the northern NSW border showed no matches within Victoria. It would seem winter water temperatures in Victoria would make the establishment of redclaw in Victorian natural waters unlikely. The predicted warming of southern Australia due to climate change may make Victoria more favorable for redclaw in the future.

Figure 8. Current production area for redclaw (Cherax quadricarinatus) within Australia (from Jones (1998)).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 13 Marron Cherax cainii (Austin) in Victoria – a literature review

5 Potential impacts of marron in Victoria There are many overseas examples of exotic and translocated freshwater crayfish impacting on endemic biota (Horwitz 1990b, Arthington and McKenzie 1997, Westman et al. 2002). Overseas translocations of freshwater crayfish have led to the displacement of native species, competition with endemic crayfish and other biota (Hill and Lodge 1999, Lodge et al. 2000, Usio et al. 2001), habitat alteration (Nystroem and Strand 1996, Rodriguez et al. 2005) and the spread of disease (Horwitz 1990b). Given the numerous examples of impacts on native biota from introduced crayfish, there is cause for concern regarding the impact on Victorian species from marron.

5.1 Disease Australian freshwater crayfish are relatively free of diseases (Horwitz 1990b, Merrick and Lambert 1991, Mosig 1998) such as the North American crayfish plague (Aphanomyces astaci), which has devastated European crayfish populations (Arthington and McKenzie 1997, Mosig 1998). Endemic diseases of Cherax species include bacterial, fungal, protozoan and nematode infections; however, outbreaks are largely a result of intensive aquaculture where unnaturally high densities of crayfish occur (Mills 1983, Merrick and Lambert 1991). Merrick and Lambert (1991) present a summary report of pathogens, parasites and commensal organisms for the three Cherax aquaculture species. Spread of marron within Victoria is likely to occur from the translocation of marron sourced from Devilbend Reservoir or OT Dam. As these marron are likely to have originated from a single introduction, the likelihood of an introduced disease associated with the population is reduced. Diseases that threaten the marron aquaculture industry in WA appear to already occur within the native yabbie population in Victoria and only pose a threat in high density aquaculture. It is likely that other endemic Victorian decapods have also been exposed to these diseases. The Mornington Peninsula marron populations would seem to pose little disease threat to endemic decapod species; however, the absence of yabbies in Devilbend Reservoir where marron are present, is cause for some concern and investigation.

5.2 Competitive interactions between crayfish Literature on the competitive interaction between marron and other freshwater crayfish is scant. In WA, where yabbies are an invasive species, they pose a threat to marron. Competition for food resources between marron and yabbies has been reported in the Hutt River in WA (Beatty 2006) but no account of changes in overall population numbers were presented and it would appear these populations have coexisted for a relatively extended period of time (Sampey, D. Marron Growers Association of Western Australia, pers.comm. 2007). In areas of the Western Australian wheatbelt, yabbies have reportedly replaced marron as the dominant crayfish in many dams. This occurred following a heavy rain event in the region, which washed large organic loads into many dams leading to population declines in freshwater crayfish. Yabbies re-established quicker than marron and have

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 14 Marron Cherax cainii (Austin) in Victoria – a literature review dominated since (C. Lawrence, Fisheries Western Australia, pers. comm. 2007). The disappearance of yabbies from Devilbend Reservoir following the introduction of marron (O’Connor 1997), may be due to competition and is cause for some concern and investigation. In Victoria, other genera of freshwater crayfish (ie. Euastacus spp.) may be more vulnerable than the yabbie to the increased competition from the establishment of marron. Some Euastacus species can take up to nine years to reach breeding maturity (Honan and Mitchell 1995, Merrick 1997), compared to two to four years for marron and one to two years for yabbies (Merrick and Lambert 1991). Additionally, many Euastacus species have restricted distributions (Horwitz 1990a), making them more vulnerable to environmental disturbance than yabbies. Two of Victoria’s Euastacus species (E. crassus and E. diversus) are listed as internationally endangered and three (E. armatus, E. bispinosus, E. neodiversus) as vulnerable (International Union for Conservation of Nature and Natural Resources). The same species are listed under the Victorian Flora and Fauna Guarantee Act as species of conservation significance. No Euastacus have been recorded near the present marron populations; however, the Yarra Spiny Cray (E. yarraensis) is found immediately north of the Mornington Peninsula, the Central Highlands Spiny Cray (E. woiwuru) to the northeast and the Gippsland Spiny Cray (E. kershawi) to the east. E. bispinosus occurs in the west of the state and may be prone to impacts from translocations from South Australia.

The impact on Victoria’s lesser known crayfish genera, Engaeus, Geocharax and Gramastacus is unknown. While Engaeus and Geocharax (commonly known as land yabbies) would be expected to utilize dissimilar habitats, Engaeus are regularly recorded in stream systems (T. Raadik, Department of Sustaianbility and Environment, pers. comm. 2007) and could interact with the marron. Six Engaeus and one Gramastacus species are currently listed under the Victorian Flora and Fauna Guarantee Act as species of conservation significance.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 15 Marron Cherax cainii (Austin) in Victoria – a literature review

6 Knowledge gaps and future considerations

To date, two known populations of marron have become established in Victorian waters. The potential for further spread remains unknown. Our knowledge on the distribution of marron in Victoria is incomplete as no data has been collected from private waters. The consequences of the spread of marron in Victoria are largely unknown but potentially significant. Key knowledge gaps are as follows:

6.1 Predicting the potential spread of marron in Victoria Very few studies have been undertaken to accurately determine the lower temperature threshold for marron survival and breeding. Existing studies have been performed under aquaculture conditions. By accurately determining this lower temperature threshold and overlaying this information with Victorian water temperature data, the potential range of marron in Victoria could be ascertained. Additionally, there is little information on the mobility of marron out of water. A study to track the movement would provide valuable data enabling us to determine the potential of marron to spread from one waterbody to the next.

6.2 Presence of marron in private waters Anecdotal reports suggest marron may be established in private waters (dams) on the Mornington Peninsula. To gain a better understanding of the actual population of marron in Victoria, information on the stocking and distribution of marron in such dams is required. Possible means of obtaining this information include:

• Consulting landholders about the presence of marron in their dams, which may be done by a survey questionnaire and/or interview.

• Survey landholders’ dams with their consent.

6.3 The impact of marron on endemic crayfish This is the greatest concern with respect to the presence of marron in Victoria. More information on the likely impacts is required. This may be obtained through:

• Controlled laboratory experiments observing interactions. • Consultation with the aquaculture industry (which may have first hand experience of interactions between yabbies and marron).

• Establishing a working group to provide advice on approaches for minimizing risk of translocations.

• Undertaking public education – through community groups such as Waterwatch, Landcare and/or schools.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 16 Marron Cherax cainii (Austin) in Victoria – a literature review

7 References

Arthington, A. H., and McKenzie, F. (1997). ‘Review of Impacts of Displaced/Introduced Fauna Associated with Inland Waters. Central Queensland University Publishing Unit: Canberra).

Austin, C. M., and Knott, B. (1996). Systematics of the freshwater crayfish genus Cherax Erichson (: Parastachidae) in South Western Australia: electrophoretic, morphological and habitat variation. Australian Journal of Zoology 44, 223-258.

Austin, C. M., and Ryan, S.G. (2002). Allozyme evidence for a new species of freshwater crayfish of the genus Cherax Erichson (Decapoda: Parastachidae) from the south-west of Western Australia. Invertebrate Systematics 16, 357-367.

Avenant-Oldewage, A. (1993). Occurrence of Temnocephala chaeropsis on Cherax tenuimanus imported into South Africa, and notes on its infestation of an indigenous crab. South African Journal of Science 89, 427-428.

Beatty, S. J. (2006). The diet and trophic positions of translocated, sympatric populations of Cherax destructo and Cherax cainii in the Hutt River, Western Australa: evidence of resource overlap. Marine and Freshwater Research 57, 825-835.

Clunie, P., Stuart, I., Jones, M., Crowther, D., Schreiber, S., McKay, S., O’Connor, J., McLaren, D., Weiss, J., Gunasekera, L., and Roberts, J. (2002). ‘A Risk Assessment of the Impacts of Pest Species in the Riverine Environment in the Murray Darling Basin’. (Murray Darling Basin Commission: Canberra).

Department of Water Resources (1989). ‘Water Victoria - A Resource Handbook’. (Department of Water Resources: Melbourne).

Dubecki, L. (2006).Fisheries Raids Take Marron off the Menu in ‘The Age’. (Fairfax: Melbourne).

Department of Fisheries (2004). http://www.fish.wa.gov.au/ Department of Fisheries: Perth).

Fisheries and Wildlife (1977). ‘Marron of Western Australia’. (Fisheries and Wildlife: Perth).

Government of Victoria (1988). ‘Fisheries Notes Policy Statement: Noxious Fish - Marron’. (Department of Primary Industries: Victoria).

Hawkins, C, Hogue, J., Decker, L. and Feminella, W. (1995). Morphology, water temperature, and assemblage structure of stream insects. Journal of the North American Entomological Society 16, 728-743.

Hill, A. M., and Lodge, D.M. (1999). Replacement of resident by an exotic crayfish: the roles of competition and predation. Ecological Applications 9, 678-690.

Honan, J. A., and Mitchell, B.D. (1995). Reproduction of Euastacus bispinosus Clark (Decapoda: ), and trends in the reproductive characteristics of freshwater crayfish. Marine and Freshwater Research 46, 485-499.

Horwitz, P. (1990a). The conservation status of Australian freshwater crustacea. Australian National Parks and Wildlife Service Report Series No 14. (Australian National Parks and Wildlife Service : Canberra).

Horwitz, P. (1990b). The translocation of freshwater crayfish in Australia: potential impact, the need for control and global relevance. Biological Conservation 54, 291-305.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 17 Marron Cherax cainii (Austin) in Victoria – a literature review

International Union for Conservation of Nature and Natural Resources (2006). ‘International Union for Conservation of Nature and Natural Resources List’. International Union for Conservation of Nature and Natural Resources.

Jones, C.M. (1990). ‘The biology and aquaculture potential of the tropical freshwater crayfish Cherax quadricarinatus’. Information Series vol. Q190028. (Queensland Department of Primary Industries: Brisbane ).

Jones, C. M. (1998). The New Rural industries, a handbook for Farmers and Investors. pp 127-133. (Rural Industries and Research Development Corporation: Barton).

Lawrence, C. (1998). Marron. in ‘The New Rural industries, a handbook for Farmers and Investors’. pp 114-119. (Rural Industries and Research Development Corporation: Barton).

Lawrence, C. S., and Morrissy, N.M. (2000). Genetic improvement of maron Cherax tenuimanus Smith and yabbies Cherax spp. in Western Australia. Aquaculture Research 31, 69-82.

Lodge, D. M., Taylor, C.A., Holdich, D.M. and Skurdal, J. (2000). Nonindigenous crayfishes threaten North American freshwater biota: Lessons from Europe. Fisheries 25, 7-20.

McDowall, R. M. (1988). New Zealand marron. Letter to the Editor. Austasia Aquaculture Magazine 3, 18.

McGuckin, J. (2001). ‘Fish Survey of Devilbend and Bittern Reservoirs, Devilbend and Tuerong Creeks’. (Streamline Research: Eltham).

Melbourne Water (2000). ‘Devilbend Future Use Strategy: Summary of Findings of Baseline Studies’. (Melbourne Water: Melbourne).

Melbourne Water (2001). ‘Devilbend. Development of a Future Use Strategy for Devilbend Reservoir’. (Melbourne Water: Melbourne).

Merrick, J. R. (1997). Conservation and field management of the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney Region, Australia. Proceedings of the Linean Society of New South Wales 118, 217-225.

Merrick, J. R., and Lambert, C.N. (1991). ‘The Yabby, Marron and Red Claw: Production and Marketing’. (J.R. Merrick Publications: Artarmon).

Mills, B. J. (1983). ‘A Review of Diseases of Freshwater Crayfish, with Particular Reference to the Yabbie, Cherax destructor’. (Department of Fisheries: South Australia).

Molony, B., Bunn, J., Bryce, C. and Durrant, B. (2004). ‘Identifying Freshwater Crayfish in the South West of Western Australia’.

Morrissy, N. M. (1976). Aquaculture of Marron, Cherax tenuimanus (Smith). Part 1 Site Selection and the Potential of Marron for Aquaculture. Fisheries Research Bulletin of Western Australia 17, 1-27.

Morrissy, N. M. (1978). The past and present distribution of marron, Cherax tenuimanus (Smith), in Western Australia. Fisheries Research Bulletin of Western Australia 22, 1-38.

Morrissy, N. M., Evans, L. and Huner, J.V. (1990). Australian freshwater crayfish: aquaculture species. World Aquaculture 21, 113-120.

Mosig, J. (1998). ‘Australian Yabby Farmer’. (CSIRO Publishing: Collingwood).

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 18 Marron Cherax cainii (Austin) in Victoria – a literature review

New South Wales Department of Primary Industries (2005). ‘Aquaculture Prospects for Freshwater Crayfish. (Department of Primary Industries: Orange).

Nguyen, T. T. T., Meewan, M., Ryan, S. and Austin, C.M. (2002). Genetic diversity and translocation in the marron, Cherax tenuimanus (Smith): implications for management and conservation. Fisheries Management and Ecology 9, 163-173.

Nystroem, P., and Strand, J.A. (1996). Grazing by a native and an exotic crayfish on aquatic macrophytes. Freshwater Biology 36, 673-682.

O’Connor, J. (1997). ‘A Survey of the Mornington Peninsula and Surrounding Areas in Search of the Noxious Species Cherax tenuimanus’. Arthur Rylah Institute for Environmental Research, Marine and Freshwater Resources Institute, Heidelberg.

Rodriguez, C. F., Becares, E., Fernandez-alaez, M., and Fernandez-alaez, C. (2005). Loss of diversity and degradation of wetlands as a result of introducing exotic crayfish. Biological Invasions 7, 75-85.

Shipway, B. (1951). The natural history of the marron and other freshwater crayfishes of south Western Australia. Western Australian Naturalist 3, 7-12; 27-34.

Smith, A. (1988). Marron in the Unites States Many questions to be answered. Austasia Aquaculture Magazine 2, 13-14.

Sutherst, R. W., Maywald, G.F., Yonow, T. and Stevens, P.M. (1999). ‘CLIMEX: Predicting the Effects of Climate on Plants and Animals’. (CSIRO Publishing: Collingwood).

Tay, M., Lymbery, A., Beatty, S., and Morgan, D. (2007). Predation by rainbow trout (Oncorhynchus mykiss) on a Western Australian icon: marron (Cherax cainii). New Zealand Journal of Marine and Freshwater Research 41, 197-204.

Tayler, D. (1988). South Australia and Victoria get tougher on marron imports. Austasia Aquaculture Magazine 2, 17-19.

Usio, N., Konishi, M. and Nakano, S. (2001). Species Displacement Between an Introduced and a ‘vulnerable’ Crayfish: The Role of Aggressive Interactions and Shelter Competition. Biological Invasions 3, 179-185.

Westman, K., Savolainen, R. and Julkumen, M. (2002). Replacement of the native crayfish Astacus astacus by the introduced species Pacifastacus leniusculus in a small, enclosed Finnish lake: a 30 year study. Ecography 25, 53-73.

Wingfield, M. (1998). ‘An Overview of Production Techniques Practiced in the Australian Crayfish Farming Industry’. (Freshwater Fisheries and Aquaculture Centre, Queensland Department of Primary Industries: Queensland).

Yabbie Growers Association Inc. (1992). ‘An Introduction to Yabbie Farming’. (Yabbie Growers Association Inc.).

Zeidler, W. (2000). Note on the origin of freshwater crayfish occurring on Kangaroo Island. Records of the South Australian Museum 33,71-72.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 19 Marron Cherax cainii (Austin) in Victoria – a literature review

Appendix 1. Climex climatic matching.

a) Manjimup b) Pemberton

c) Esperance d) Dwellingup

e) Kingscote f) Mornington

CLIMEX climatic matching (Match level = 70%+) for endemic marron sites a) Manjimup, b) Pemberton; extended WA range c) Esperance, d) Dwellingup; and interstate translocated populations, e) Kingscote and f) Mornington.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 20 Marron Cherax cainii (Austin) in Victoria – a literature review

0-24 25-49 50-75 75-100

CLIMEX climatic matching for Mornington with matching requirements reduced to 0%.

Arthur Rylah Institute for Environmental Research Technical Report Series No. 167 21

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