ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES &

RECOMMENDATIONS FOR IMPROVING

FRESHWATER ECOSYSTEM HEALTH

Report to:

MW Klunzinger, SJ Beatty, DL Morgan, MG Allen & AJ Lymbery Centre for Fish & Fisheries Research Murdoch University ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSEDecember 2011 TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Report to:

Lowlands Conservation Association Serpentine River Group Western Australian Government

This report should be referenced as: Klunzinger, M.W., Beatty, S.J., Morgan, D.L., Allen, M.G. & Lymbery, A.J. (2011). Ecology of aquatic fauna in the Serpentine River in response to land use practices & recommendations for improving freshwater ecosystem health. Murdoch University, Centre for Fish & Fisheries Research, Report to Lowlands Conservation Association, Serpentine River Group and the Government of Western Australia.

Authors: Acknowledgements: MW Klunzinger, SJ Beatty, MG Allen, This project was funded by the state Natural DL Morgan & AJ Lymbery Resource Management regional and Centre for Fish & Fisheries Research, community groups program 2009-2010 through

Murdoch University the government of Western Australia. We would like to thank Mark Angeloni (Lowlands December 2011 Conservation Association Chairman) for project co-ordination. Thanks to Midge Richardson (Lowlands Conservation Association), Rupert Richardson (Serpentine River Group), Bill Richardson (Riverlea), SJ Shire, James Keleher, students of Central Institute of Technology, Gun Dolva, Kerry Trayler, Julie Robert and others for supporting the study.

Frontispiece: from top to bottom - Western minnow (Galaxias occidentalis) photo: Mark Allen; Serpentine River within Lowland’s conservation block (Bush Forever site 368) photo: Michael Klunzinger; Carter’s freshwater mussel (Westralunio carteri) photo: Michael Klunzinger.

2 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Summary The Serpentine River is situated 60 km south of Perth, Western Australia, with headwater streams converging and flowing in the Serpentine Dam above the Darling Scarp, which continues westward through the Pipehead Dam, over Serpentine Falls in an uncleared national park, through agricultural land with a brief interruption of uncleared bush within Lowlands Bush Forever Site 368 before flowing through Lowlands/Riverlea cattle property and turning southward where it converges with Birrega Drain. Birrega Drain flows into a series of lakes that empty into the Peel-Harvey Estuary. This project addressed three investment priorities from the WA State NRM Program 2009/10 funding round including 1) Biodiversity, 2) Biosecurity and 3) Water Quality within the Serpentine River in Lowlands Bush Forever Site 368, Lowlands/Riverlea livestock properties and the Birrega Drain.

1) Biodiversity: • Baseline surveys revealed that native freshwater fishes, crayfishes and well- developed tadpoles were generally more abundant in the heavily vegetated areas with complex habitats which included sandy/silty sediments overlain with woody debris, macrophytes and overhanging riparian vegetation. • Degraded sites, which included two gauging stations and areas formerly impacted by cattle housed fewer of the Vulnerable Priority 4 Carter’s Freshwater Mussel (Westralunio carteri) and native fishes and had an increased density of feral fishes as well as the presence of feral crayfishes (The Yabby: Cherax destructor). • Glochidia (larval W. carteri) were more prevalent in native than feral fish and were more prevalent within the Bush Forever sites which contained more freshwater mussels/m2 than the degraded sites. 2) Biosecurity: • The feral Eastern Gambusia dominated the fish fauna and reached plague proportions in the late spring and early summer, more so in the degraded sites downstream of the Lowlands Gauging Station, but upstream habitats also housed the pest species in reasonably large numbers. This species was probably responsible for the extreme fin nipping observed on juvenile Western Pygmy Perch and may have been responsible for the relative rarity of this native fish in the area. • Goldfish were restricted primarily to a turbid breeding pool in the Birrega Drain and below the Lowlands Gauging Station weir within the Serpentine River. Electro-fishing and seine netting was successful in reducing the species in terms of both subsequent size captures and number of fishes captured.

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3) Water Quality: • The exceptionally dry year in 2010 adversely affected native freshwater fauna such as Carter’s Freshwater Mussel (Westralunio carteri) populations through mortality from extreme drying within the Birrega Drain, but populations within the Lowlands Bush Forever Site 368 were more resilient due to up to seven degrees (°C) cooler water temperatures, moist sediments and shading from riparian vegetation and woody debris. • The Serpentine River remained fresh (<1.0 ppt salinity), but the Birrega Drain became salinised (>1.0 ppt salinity) with the onset of hot, dry weather and evaporation. Had salinities risen much above 2.0 ppt, more Carter’s Freshwater Mussels could have perished. • Regular water sampling revealed that Total Phosphorus concentrations rose as water levels receded and indicated that the system is essentially eutrophic for much of the year. • During rainfall events, the water from the Serpentine River leaving Lowlands was visually far less turbid than that of the Birrega Drain. • Flow was noticeably greater in 2011 than in the previous year which probably assisted with more prevalent aquatic macrophytes such as Triglochin and the upstream migration of gravid native freshwater fishes in August 2011.

Recommendations 1) Install a bridge at the cattle crossing over Serpentine River on the Lowlands/Riverlea property to reduce erosion, sedimentation and nutrient inputs from cattle and enhance the river with woody debris to encourage native freshwater fish and freshwater mussel re-colonisation and follow-up monitoring. 2) Re-plant native riparian vegetation, especially shading sedge, shrubs and trees in degraded sites including the cattle crossing (post bridge construction) and impacted areas downstream from Lowlands Gauging Station and within the Birrega Drain. 3) Re-planting native riparian vegetation and trees lining the Birrega Drain and placing more large woody debris within the stream should allow recolonisation of native freshwater fish, crayfish, mussels and other fauna and improve water quality by reducing ambient and thus water temperature as well as surface water evaporation. 4) Providing adequate supplies of good freshwater, low in contaminants and chemicals, particularly during times of hot, dry weather will help maintain aquatic ecosystem integrity through flows that will allow the system to remain perennial, maintain deep refuge pools and maintain water supplies for river users.

4 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Contents

Summary and Recommendations……………………………………………..……………………………………. 3 Introduction……………………………………………………………………………..……………………………………. 6 Study area……….……………………………………………………………..…………………………………...... 6 Bush Forever………………………………………………………………………………………….……………...... 6 Aquatic freshwater biodiversity of south-western Australia...... 8 Aims of the study…………………………………………………………………………………………...... 13 Methodology………………………………….………………………………………………………………………………. 14 Sampling sites………………………………………………………………………………………………...... 14 Habitat characterization and riparian vegetation surveys…………………………………...... 14 Freshwater fish and crayfish sampling………………………………………………………………...... 15 Freshwater mussel sampling…………………..…………………………………………………………...... 19 Water quality sampling methods………………………………………………………………………...... 19 Statistical analysis……………………………..………………………………………………………………...... 20 Results and discussion………….…………………………………..……………………………………………………. 21 Habitat characterization and riparian vegetation surveys……..…………………………...... 21 Environmental variables of water quality………………………..……..…………………………...... 27 Summary of fish, crayfish and other fauna captures……….……..…………………………...... 35 Patterns of fish migration………………………………………………..……..…………………………...... 37 Distribution patterns and population structure of native fishes……..……………………...... 43 Distribution, movement patterns and population structure of freshwater crayfishes...... 75 Distribution patterns, population structure and eradication of feral fishes……..………...... 87 Distribution, abundance, population structure and host-fish of Carter’s Freshwater Mussel..………. 101 Conservation significance and management recommendations…………..……………….………. 113 References…………………………………………………………………………………………………..…………….…….115 Appendices…………….…………………………………………………………………………………..…………….……. 121 Extension of this study……….…………………………………………………………………………...... 121 Characteristic riparian vegetation observed during this study……………………………...... 127 Lowlands and the Serpentine River – Then and now…………….……………………………...... 138

5 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Introduction

Study area

The Serpentine River, located 60 km south of Perth, WA, drains into the Peel-Harvey Estuary. The first order streams in the upper catchment converge and flow into the Serpentine Dam, which was completed in 1961. Below the Serpentine Dam is the Pipehead Dam which was completed in 1957. The Serpentine River continues to flow through Lowlands (Bush Forever Site 368) and Riverlea properties (Figure 1) before converging with the channelized Birrega Drain which flows into a series of lakes that empty into the Peel-Harvey Estuary. The study area of the Serpentine River and Birrega Drain is classified as freshwater with salinities typically less than 1 g/L (Pen 1999). The study area includes Lowlands Bush Forever site 368, Riverlea and Lowlands cattle properties and a short section of the Birrega Drain adjacent to Dog Hill Gauging Station (AWRC 614030).

Bush Forever

Bush Forever is a strategic plan to protect ca. 51,200 hectares of regionally significant vegetation complexes of the natural vegetation of the Swan Coastal Plain, or, if altered, still represents the structure and floristics of natural vegetation which provides the necessary habitat for native fauna (WAPC 2000). Bush Forever site 368 is located within the Eastern Block of the Lowlands property, Peel Estate, which is owned by the Richardson family and managed as a conservation area by Lowlands Conservation Association.

6 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

5 3 2 4 1 6

1 2 3 4

5 6

Figure 1. Sites sampled for freshwater fishes, crayfishes and mussels in the Serpentine River catchment during this study. Images adapted from GoogleMaps™. Red represents ‘Degraded’ sites and green represents ‘Natural’ sites.

7 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Aquatic freshwater biodiversity of south-western Australia

Freshwater fishes

The freshwater fishes of the South West Coast Drainage Division of Western Australia (WA) belong to four families and are few in terms of number of species, but highly endemic with nine of the 11 being found nowhere else (Morgan et al. 1998, Allen et al. 2002Morgan et al. 2011). In fact, this drainage division has the highest proportion of endemic freshwater fishes of any of Australia’s 11 major drainage divisions (Morgan et al. 1998). None of the south-west freshwater fishes is shared with the other two WA divisions; the Pilbara and Kimberley (Morgan et al. 1998, 2011; Allen et al. 2002). Two species are listed federally under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999): the Western Trout Minnow (Galaxias truttaceus), Australia’s only Critically Endangered freshwater fish, and Balston’s Pygmy Perch (Nannatherina balstoni) listed as Vulnerable. A few species, including those mentioned above and the Western Mud Minnow (Galaxiella munda), are listed as Schedule 1 (rare or likely to become extinct and in need of special protection) under State legislation (Wildlife Conservation Act 1950).

While the fishes of the Peel-Harvey estuaries have been well studied (e.g. Potter et al. 1983, Lenanton et al. 1984, Loneragan et al. 1986, McComb & Humphries 1992, Potter & Hyndes 1994, Lavery et al. 1999, Veale et al. 2010), the freshwater fishes of its major tributaries, namely the Serpentine River, have received far less research attention. Apart from a technical report by Davis et al. (1988), there appears to have been no focused studies on the freshwater fishes and other fauna in the Serpentine River. Elsewhere in SWWA however, a large body of research has done much to increase our understanding of the biology and ecology of the freshwater fishes and crayfishes of the region (Morgan et al. 2011 and references therein).

Recent studies have quantified the salinity tolerances of some of SWWA’s endemic freshwater fish species and found that Western Minnow (Galaxias occidentalis) and Western Pygmy Perch (Nannoperca vittata) are negatively affected by salinities greater than 14 g/L and the federally listed Vulnerable Balston’s Pygmy Perch (Nannatherina balstoni) is more sensitive to salt with salinities above 8 g/L producing ill effects (Beatty et al. 2011). Beatty et al. (2010) showed the importance of groundwater contribution in maintaining freshwater fish populations.

The presence of an introduced parasitic crustacean Lernaea on freshwater fishes in the Canning River by Marina et al. (2008) also raises species conservation concerns. Watts et al. (1995) examined the genetics and morphology of the Western Minnow (Galaxias occidentalis). There are also a number of unpublished technical reports and theses on fishes in the region. For the Swan Coastal Plain some examples include studies reported by Aquatic Research Laboratory (1988), Morrison (1988), Hewitt (1992), Bamford et al. (1998), Morrissy (2000), Morgan et al.

8 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

(2000), Morgan & Beatty (2003a, b, c), Beatty et al. (2003), Maddern (2003), Tay (2005), Molony et al. (2005), Beatty & Morgan (2006), Morgan & Beatty (2006), Morgan & Beatty (2007), Morgan et al. (2007), Beatty & Morgan (2008), Morgan et al. (2008), Morgan et al. (2009), Beatty et al. (2010a,b), and Beatty et al. (2011).

In light of the lack of published data and/or technical reports detailing the freshwater fishes of the Serpentine River, it is important to note that there is a large unpublished data set of fishes in the ‘freshwaters’ of the catchments of SWWA (>1800 sites), which is maintained by the Freshwater Fish Group in the Centre for Fish & Fisheries Research, Murdoch University.

Freshwater crayfishes

Each of the 11 freshwater crayfish species is endemic to the south-west region. This includes six species in the genus Cherax; the most widely distributed freshwater crayfish genus in Australia (Austin & Knott 1996; Austin & Ryan 2002). The long period of separation of south- western Australia from the rest of the continent, has led to the native Western Australian Cherax species being monophyletic (Crandall et al. 1999). The Cherax species are perhaps best known for the iconic Smooth Marron (Cherax cainii), a favoured recreational species managed by the WA Department of Fisheries, and a delicacy for seafood connoisseurs. The species is farmed by licensed WA aquaculturalists, sold locally and exported live to North Asian and European markets (Alonso 2009). Other species include the more common and widespread Gilgie (Cherax quinquecarinatus) and Koonac (Cherax preissii) as well as the less common Restricted Gilgie (Cherax crassimanus) from Margaret River to Denmark and Glossy Koonac (Cherax glaber), restricted to the extreme south-western corner between Dunsborough and Windy Harbour (Morgan et al. 2011). Listed as Critically Endangered under the EPBC Act 1999, the Hairy Marron (Cherax tenuimanus) is now found only in the upper reaches of Margaret River (TSSC 2004; Morgan et al. 2011). There are also five native species of obligate burrowing freshwater crayfish that belong to the endemic genus Engaewa (Horwitz & Adams 2000), with three of these recently being listed under the EPBC Act 1999 as Critically Endangered (Dunsborough Burrowing Crayfish (Engaewa reducta) and Margaret River Burrowing Crayfish (Engaewa pseudoreducta)) or Endangered (Engaewa walpolea). Another decapod crustacean, the South-west Glass Shrimp (Palaemonetes australis) is common and widespread throughout the region, an important food source for other aquatic species (Horwitz 1995; Morgan et al. 2011) and has been suggested as being important in the release of glochidia from freshwater mussels (Klunzinger 2011).

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Freshwater mussels

Freshwater mussels are benthic bivalve molluscs, which play important functional roles in aquatic ecosystems through biological filtration of water, contributing to clarity; through their burrowing movements, they oxygenate sediments; their shells provide structure and refuge for other organisms such as juvenile fishes and crayfishes; they provide food for predators and were traditionally used as a food source by indigenous peoples (e.g. McNally 1960; Vaughn and Hakenkamp 2001; Walker et al. 2001; Strayer 2008; Bettink 2011; Morgan et al. 2011). Freshwater mussels are sensitive to environmental changes (Ponder & Walker 2003) and, like freshwater fish fauna, can be considered important bioindicators of aquatic ecosystem condition.

The region’s only freshwater mussel: Carter’s Freshwater Mussel (Westralunio carteri) is endemic to the south-west (McMichael & Hiscock 1958; Walker 2004). This bivalve has a unique life cycle in which its larvae, known as ‘glochidia’ must attach to a host, which is generally a fish to complete its development to the juvenile mussel stage. This interaction is thought to serve as a dispersal mechanism (Bauer & Wächtler 2001; Strayer 2008). Until recently, little was known of the species biology, reproductive development, ecology and its host fishes (Lymbery et al. 2008; Klunzinger et al. 2011a). Kendrick (1976) documented the disappearance of W. carteri from the Avon River, presumably as a result of secondary salinisation. In recent years, the species has undergone population contractions in parts of its range, also presumed to be linked with salinisation of waterways within the south-west agricultural zones (Keighery et al. 2004) and was listed as ‘Vulnerable’ under international conservation criteria (IUCN 2011). The species is categorized as ‘Priority 4’ fauna under an interdepartmental listing by the Western Australian Department of Environment and Conservation (DEC 2011), meaning that the species is in need of monitoring. Recent work by Klunzinger et al. (2010) has shown that the species is intolerant of salinities above 3.0 g/L, dehydration can cause localized population reductions (Klunzinger et al. 2011b) and field reports have shown that low dissolved oxygen (<20%) also causes mortality (Klunzinger et al., unpublished data).

Fauna declines

These aquatic fauna have undergone major declines in population range due to a combination of habitat change, such as riparian vegetation degradation and secondary salinisation of inland reaches of the major rivers (Morgan et al. 1998, 2003) and impacts of introduced species such as Eastern Gambusia (Gambusia holbrooki) and Goldfish (Carassius auratus) (e.g. Morgan et al. 1998, 2002, 2004, Gill et al. 1999). The major impact on the distribution of these populations

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has been dryland secondary salinisation of inland areas, which has resulted in only ~44% of flow in the largest 30 rivers in the south-west of WA being fresh (Mayer et al. 2005).

Exacerbating these impacts on our unique aquatic fauna is the continuing decline in rainfall. Average annual rainfall in the south-west of WA has declined by 10% since 1970. The ranges of predicted future average annual rainfall declines are: by 2030 between 3-22% and 0- 22% for the extreme south-west and the remainder of the region, respectively (Suppiah et al. 2007). By 2070, models predict annual average rainfall to decline by 7-70% and 0-70% for the extreme south-west and the remainder of the region, respectively (Suppiah et al. 2007). The reduction in stream flow and groundwater recharge due to the continued decline in rainfall has considerable implications in sustainably managing surface and groundwater resources.

The freshwater fishes of the region have recently been identified as important bioindicators of water quality decline (such as salinisation, Beatty et al. 2011) and, being at the top of the aquatic food chain, play an important role in the structuring of aquatic food webs (Beatty & Morgan 2010). Freshwater mussels have also been shown to be bioindicators of aquatic ecosystem condition for their propensity to bioaccumulate contaminants, are relatively long lived (>20 years), limited mobility and are sensitive to environmental changes in water quality (Storey & Edward 1989; Mutvei & Westermark 2001). These freshwater fauna should, therefore, be a key consideration in developing and monitoring the success of river management plans.

Feral freshwater species

Several ‘waves’ of non-endemic (feral) fish introductions to the south-west have occurred since the 1870s (Figure 2). Brown Trout (Salmo trutta), Rainbow Trout (Onchorhynchus mykiss), Silver Perch (Bidyanus bidyanus) and Redfin Perch (Perca fluviatilis) were introduced as game fish between the 1870s and early 1900s. Several populations of these large predatory fishes have established self-maintaining populations within freshwater rivers, lakes and reservoirs of the region and government stocking programs often continue to this day (Morgan et al. 2004, 2011). These feral species have been shown to deplete local stocks of the much smaller endemic native freshwater fishes and can have a devastating effect on the iconic Marron (see Morgan et al. 2004, Tay et al. 2007).

During the 1930’s, Eastern Gambusia were introduced in great numbers to control mosquito infestations throughout Australia by the government health department with the aim to reduce mosquito-borne human and livestock diseases; it was thought that the tremendous breeding capacity of this species, bearing live offspring, would control mosquito populations (Morgan et al. 2004). In reality, native freshwater fishes, such as Western Pygmy Perch have been shown to be more effective in control nuisance insects (Gill et al. 1999). Gambusia are

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very territorial and often outcompete native species for habitat and through their aggressive habit of fin-nipping (Morgan et al. 2004).

Since the 1970’s, the new wave of feral fishes has been steadily increasing with the introduction of ornamental fishes such as Goldfish and Koi Carp (Cyprinus carpio) and, more recently, the introduction of Pearl Cichlid (Geophagus brasiliensis), amongst others. These fishes negatively impact aquatic habitats through bioturbation of sediments, stimulation of cyanobacterial growth and re-suspension of nutrients, preying on native molluscs, native fish eggs and native fish larvae (Morgan et al. 2004; de Graaf & Coutts 2010; Beatty et al. 2010a).

The freshwater crayfish Yabby (Cherax destructor) was introduced into WA as an aquaculture species, but has escaped from farm dams into local waterways where they have taken up residence and often out compete other native freshwater crayfishes such as Marron or Gilgies due to their life-history traits and greater tolerance to environmental water quality extremes, such as higher temperatures and hypoxic conditions during summer (Morrissy et al. 1984; Horwitz 1990; Beatty et al. 2005a).

16

14

12

10

8

6

4

Numberestablished species 2

0 1860 1880 1900 1920 1940 1960 1980 2000

Year Figure 2. History of exotic fish species introductions in Western Australia (1870-2010).

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Aims of the study

Given that very little is known about the aquatic fauna of the lower Serpentine River, the current study aimed to collect information required to assess the current and future health of the aquatic ecosystems of this river. The aims of this study, therefore, were to:

• Establish and classify habitats present within the study area. • Determine the distribution and population structure of fish, decapods and freshwater mussels in Lowlands Bush Forever Site 368, Riverlea and Lowlands agricultural properties. • Monitor water quality, fishes, decapods and freshwater mussels and to quantify any differences in these fauna between sites. • Eradicate feral fish species. • Identify priorities for management adaptation.

Carter’s freshwater mussel and Western pygmy perch, two of south-western Australia’s freshwater bioindicators of river health. (photographs M. Klunzinger and M. Allen)

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Methodology

Sampling sites

A total of six sites were assessed using qualitative (presence/absence) and quantitative (abundance and density) methods to provide details of the freshwater fishes, crayfishes and mussels within a 7 km section of the Serpentine River within Lowlands Bush Forever Site 368 and Riverlea and Lowlands cattle grazing properties as well as a section of the Birrega Drain (Figure 1). When sites were accessible, sampling occurred every 4-8 weeks from June 2010 to September 2011. Sampling was discontinued when either (1) water levels were too high and flow was too strong or (2) the river was too dried out to sample. Riparian vegetation surveys were used to assist in site classifications.

In order to provide an overall summary of the previously known distribution of fishes in the Serpentine catchment, the Freshwater Fish Group (Murdoch University) distributional database was accessed and the distribution of each species in this catchment were then mapped and included in the species synopses. Additional information was accessed from Western Australian Museum records and technical reports from other researchers.

Habitat characterisation and riparian vegetation surveys

Habitats within each site were subjectively characterised as either ‘Degraded’ or ‘Natural’. Degraded sites were those which were heavily influenced by disturbance from livestock or human activity. Natural sites were those in which disturbance was less evident and habitats more closely resembled a typical undisturbed riparian zone. We are careful to point out, however, that no site was truly undisturbed because they had, at one time or another, been either impacted by human activity and/or influenced by livestock at some point in the family history of the property (see appendix for examples).

Baseline information was collected on the riparian vegetation communities at the six sites along the Serpentine River and Birrega Drain. An approximate percentage cover of vegetation comprising the over-, middle- and under-storey for a distance up to 20 metres either side of the stream line was estimated visually for each site and the most dominant species comprising each vegetation layer recorded. In cases where identification of taxa could not be determined on site, a voucher specimen was collected, pressed and dried for subsequent identification at the Western Australian Herbarium using the collection and various botanical identification references (e.g. Marchant 1987, Wheeler et al. 2002, Hussey & Keighery 2007).

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Freshwater fish and crayfish sampling

A variety of sampling techniques were deployed during the study, depending on the type of in- stream habitat present at each site. The use of such a variety of specialised sampling techniques helped to ensure that all species present at each site were recorded. Fyke nets (0.8 m height, 5 m wide wings, 1.2 m wide opening, 5 m long pocket with two funnels all comprised of 2 mm woven mesh) were set at a number of sites for a 24 hr period, ensuring an adequate proportion of the funnel was above the water surface to ensure survival of any incidentally captured air-breathing animals such as reptiles, birds and mammals (Figure 3). A Smith-Root (Model LR20) backpack electro-fisher were also employed to capture fishes to estimate fish density and was the most effective methods to capture feral fishes, which are often under- represented in fyke net captures (Figure 3). Fishes were measured for total length (TL) and crayfishes were measured for orbital carapace length (OCL) (see Figures 4 and 5). Where possible, the sex and reproductive status of fishes and crayfishes was determined by external examination.

Sub-samples of fishes from each site were transported live in aerated eskies containing river water to the laboratory and then euthanized with an overdose of AQUI-S™ and examined microscopically for the presence of glochidia attached to the fins and gills during November, December 2011 and January and September 2011. Before this study, nothing was known of the host fishes of this Vulnerable, P4 freshwater mussel.

Michael Klunzinger checking fyke nets at Rapids Rd; Photo: Stefania Basile.

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(A)

(B)

Figure 3. Methods used to capture fishes in the study area. (A) Electro-fishing. Dr Stephen Beatty (left) and James Keleher, BSc[Hons] (right), Murdoch University. (B) Fyke nets (upstream movement [white arrow], downstream movement [black arrow]). Notice spaces above water line that form pockets for air-breathing animals that may be inadvertently captured.

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OCL

Figure 4. Orbital Carapace Length (OCL) of freshwater crayfish (Gilgie – Cherax quinquecarinatus shown here).

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(A)

TL

(B)

TL Figure 5. Total Length (TL) of fish measured using a measuring board with ruler. (A) Nightfish – Bostockia porosa. (B) Freshwater cobbler – Tandanus bostocki.

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Freshwater mussel sampling

At each site, a 50 m stretch of stream was visually examined for freshwater mussels from the water surface or feeling for mussels by hand when water clarity was poor. To determine the relative density of freshwater mussels, 10 x 1 m2 quadrats were randomly placed on the stream bed at each site. Quadrats were constructed of 15 mm diameter round PVC tubing and open elbows. The number of mussels in each quadrat were then counted to estimate population density, as recommended by Strayer & Smith (2003). At each site, we recorded substrate type on the river bottom (rock, gravel, sand, mud, silt and/or detritus, woody debris, etc.). For each mussel collected from the quadrats, the maximum length (ML), maximum height (MH) and width (W) of the shell was measured with vernier callipers to the nearest 0.01 mm (Figure 6). Mussels were identified to species level using taxonomic keys of McMichael & Hiscock (1958) and Walker (2004). The majority of mussels were released after being measured, with a small number retained for future genetic analyses. Using these measurements, Maximum Height Index (MHI) and Shell Obesity Index (WLI) according to McMichael & Hiscock (1958) was derived from the following formulas:

= × 100 and = × 100. 푀퐻 푊 Fish푀퐻퐼 that푀퐿 were captured in 푊퐿퐼fyke nets푀퐿 and through electro-fishing were examined for glochidial cysts, which appeared as small, white, bladder-like cysts on fish epithelial tissue. Glochidia prevalence (GP) was calculated as a percentage of fish infected of the total number of each individual fish species examined. Glochidia intensity (GI) was calculated by counting the number of cysts on each infected fish.

Water quality sampling methods

Physico-chemical parameters of water quality (temperature (°C), pH, dissolved oxygen (DO as % and ppm), NaCl concentration (ppt), total dissolved solids (TDS as ppt) and conductivity (µS/cm)) were measured using an Oakton™ PCD650 waterproof portable multimeter at three locations at each site and a mean and standard error (SE) determined on each sampling occasion. Additionally, water samples (200 mL) were collected from a depth of ca. 200 mm below the surface before entering the water at each site on each sampling occasion from June 2010 to February 2011. Water samples were subsequently analysed for total phosphorus (tP) at Murdoch University’s Marine and Freshwater Research Laboratory (MAFRL) as an indicator element according to trigger values under ANZECC guidelines for freshwater ecosystem health (ANZECC & ARMCANZ 2000).

19 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Maximum Height

Maximum Length Width

Figure 6 Morphological measurements of freshwater mussels (from McMichael & Hiscock 1958).

Statistical Analysis Mapping of faunal distributions was undertaken using MapInfo. Graphical and statistical analysis of the fish, decapods and mussel abundance, densities, and length-frequencies were undertaken using MS Excel®, JMP®4 and SigmaPlot®11.0. Baseline information was collected on the riparian vegetation communities at six sites along the Serpentine River. An approximate percentage cover of vegetation comprising the over-, middle- and under-storey for a distance up to 20 metres either side of the stream line was estimated visually for each site and the most dominant species comprising each vegetation layer recorded. In cases where identification of taxa could not be determined on site, a voucher specimen was collected, pressed and dried for subsequent identification at the Western Australian Herbarium using the collection and various botanical identification references (e.g. Marchant 1987, Wheeler et al. 2002, Hussey & Keighery 2007). Differences in riparian vegetation among sampling sites were tested using methodology from Lymbery et al. (2003). For each fish species at each sampling site and for each fish species over all sampling sites, glochidia prevalence (percentage of fish infested) and mean intensity (number of glochidia per infested fish) was calculated. Ninety five percent confidence limits were calculated for prevalence, assuming a binomial distribution and intensity, from 2,000 bootstrap replications, using the software Quantitative Parasitology 3.0 (Rozsa et al. 2000). Differences in prevalence among fish species or sampling sites were tested by Chi-square analysis and differences in intensity by a non-parametric Kruskal-Wallis test. The relationships of fish species among sampling sites for peak glochidia prevalence and intensity were tested by Regression Analysis.

20 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Results and discussion Habitat characterisation and riparian vegetation surveys

For the purpose of this study, sites were classified as either ‘Degraded’ or ‘Natural’. Canopy, middlestorey and understorey species composition and percentage of cover of riparian vegetation were the primary factors used to classify each site.

‘Degraded’ sites

1) Dog Hill Gauging Station

This lowermost section of the Serpentine River was highly degraded. There was a large human-made levee on the side of the river where the gauging station was built and the stream bed itself has been lined with rock in parts. Remnant pools are extremely turbid and sedimented. The overstorey was sparse (~ 10% canopy cover) and dominated by Flooded Gum (Eucalyptus rudis). Other tree species included Swamp Sheoak (Casuarina obesa) and Swamp Paperbark (Melaleuca rhaphiophylla). The middlestorey was also sparse (~ 25% cover) with isolated occurrences of River Astartea (Astartea leptophylla), Robin Red Breast (Melaleuca lateritia) and Stinkwood (Jacksonia sternbergiana). The continuous understorey (> 85% cover) consisted mostly of weeds, the most common of which were Water Couch (Paspalum dilatatum) at the edge of the river, and Watsonia (Watsonia sp.) and Perennial Veldtgrass (Ehrharta calycinus) further up the bank. A number of sedges, mostly invasive weed species, occurred in the riparian zone such as Scaly Sedge (Cyperus tenuiflorus), Cyperus congestus, and Juncus microcephalus. Large thickets of the native Jointed Twig-rush (Baumea articulata) also occurred on the margins of the river at this site.

2) Serpentine River - Birrega Drain Confluence

This degraded site abuts extensive cleared land beyond the banks of the river on either side. The riparian zone was fenced off from stock and the overstorey was relatively intact (~ 60% canopy cover) being dominated by Flooded Gum (Eucalyptus rudis) and Swamp Paperbark (Melaleuca rhaphiophylla). However, the middlestorey was very sparse (< 10% cover) and represented by a solitary species: River Astartea (Astartea leptophylla). The understorey at this site was somewhat patchy (~ 65% cover) and again dominated by weeds such as Watsonia (Watsonia sp.), Water Couch (Paspalum dilatatum), Cyperus congestus, Common Rush (Juncus usitatus), and the herb Grammatotheca bergiana. There was considerable bank erosion at this site from vehicles crossing the stream.

3) Lowlands Gauging Station

This was another degraded site, similar floristically to the previous site. The overstorey was patchy (~ 40% canopy cover) with Flooded Gum (E. rudis) and Swamp Paperbark (M. rhaphiophylla) and the middlestorey was virtually non-existent (< 5% cover), with only isolated taller thickets of Common Rush (Juncus usitatus). The dense (~ 70% cover), weedy understorey was dominated by Water Couch (Paspalum dilatatum), Cyperus congestus, Common Joyweed (Alternanthera nodiflora), and other weed

21 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

grass species (Poaceae). There was extensive evidence of bank collapse and erosion on both sides of the river at this site. It was used as a stock watering point but the riparian zone is mostly fenced off. A large section of riparian zone was undergoing revegetation at this site but most seedlings did not survive the extremely hot and dry summer conditions.

‘Natural’ sites

4) Coffee Rocks

This site was located on a part of the Lowlands property that was isolated from livestock so was in much better condition than previous sites, with an intact overstorey. The overstorey again consisted of Flooded Gum (E. rudis) and Swamp Paperbark (M. rhaphiophylla) and was fairly continuous (> 85% canopy cover). The middlestorey was dense (~ 60% cover) and more diverse than the downstream sites. Common species in this vegetation layer were River Astartea (A. leptophylla), Spreading Sword-sedge (Lepidosperma effusum), and Bracken Fern (Pteridium esculentum). Weeds predominated in the patchy understorey (~ 30% cover) with Water Couch (P. dilatatum), Common Rush (Juncus usitatus), and Cyperus congestus most common near the water’s edge and Perrenial Veldtgrass (E. calycinus) and Watsonia (Watsonia sp.) occurred further up the bank. Isolated clumps of the native aquatic plant Water Ribbons (Triglochin linearis) occurred at this site.

5) Horse Drink

This site, located near the old Lowlands homestead, had an intact overstorey (> 85% canopy cover) dominated by Flooded Gum (E. rudis) and Swamp Paperbark (M. rhaphiophylla). The middlestorey was patchy (~ 40% cover) but was notable for the occurrence of the Priority 4 listed taxa Parsonsia diaphanophleba a woody climber. Other common species were River Astartea (A. leptophylla) and the exotics: Common Rush (Juncus usitatus) and Tall Fleabane (Conyza sumatrensis). The understorey was patchy (~ 30% cover) and dominated by weeds such as Water Couch (P. dilatatum), Cyperus congestus, Grammatotheca bergiana, and Pennyroyal (Mentha pulegium). Water Ribbons (Triglochin linearis) occurred in the stream and at the water’s edge.

6) Lowlands Forest

This site was located uppermost in the catchment of all sites sampled during the study and was very similar floristically to Horse Drink with a mostly intact overstorey. The overstorey consisted of Flooded Gum (E. rudis) and Swamp Paperbark (M. rhaphiophylla) and was almost continuous (~ 70% canopy cover). The middlestorey was patchy (~ 40% cover) and featured a mix of native species such as River Astartea (A. leptophylla), Orange Wattle (Acacia saligna), Bracken Fern (Pteridium esculentum), Parsonsia diaphanophleba and introduced weeds like the Common Fig (Ficus carica), Tall Fleabane (C. sumatrensis) and Common Rush (J. usitatus). The understorey was patchy (~ 20% cover) and almost exclusively comprised of weeds such as Water Couch (P. dilatatum), Cyperus congestus, Pennyroyal (M. pulegium), Grammatotheca bergiana, and Mexican Tea (Dysphania ambrosioides). Water Ribbons (Triglochin linearis) occurred sporadically in the stream. There was severe bank collapse along the

22 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

southern side of the river at this site. Large high voltage power lines cross the river here and maintenance has also caused disturbance to the understorey.

Plant-species richness and diversity

Table 1 shows the mean number of dominant plant species (S), Margalef’s index (d) and Shannon- Wiener index (H) for each site. There were no significant differences in S between degraded and natural sites.

Table. Mean number of dominant plant species (S), Margalef’s index (d) and Shannon-Wiener index (H) for each site qualitatively sampled for riparian vegetation within the Serpentine River and Birrega Drain. Site S d H’(loge) Dog Hill 10 3.91 2.30 Serpentine-Birrega Confluence 9 3.64 2.20 Lowlands Gauging Station 7 3.08 1.95 Horse Drink 10 3.91 2.30 Coffee Rocks 10 3.91 2.30 Lowlands Forest 14 4.93 2.64

Differences in plant communities across sites

Overall

When all plant species included the overstorey, the middle storey and the understorey were considered together, the two-dimensional ordination plot of Bray-Curtis similarity coefficients of overall plant- species composition among sites suggest there was no apparent separation among sites along both axes (Figure 7), ANOSIM (R = 0.43, P = 0.20).

Considering only native plant-species in the understorey, the two-dimensional ordination plot of Bray-Curtis similarity coefficients of native plant-species composition among sites suggest that there was some separation among sites along both axes (Figure 8), although this separation was not strongly significant and appeared merely as a trend, as confirmed by ANOSIM (R = 0.67, P = 0.10). This separation was due to the fact that riparian native plant-species were virtually non-existent in the understorey within Coffee Rocks and Lowlands Gauging Station sites and that Horse Drink and Lowlands Forest were similar in that they had fewer weeds and a greater number of native plant-species in the understorey (Figure 9).

23 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Figure 7. Two-dimensional ordination plot of Bray-Curtis similarity coefficients of overall plant species composition among sites sampled for riparian vegetation within the riparian zone of the Serpentine River and Birrega Drain. Site codes: DH = Dog Hill; SBC = Serpentine-Birrega Confluence; LGS = Lowlands Gauging Station; CR = Coffee Rocks; HD = Horse Drink; LF = Lowlands Forest.

Figure 8. Two-dimensional ordination plot of Bray-Curtis similarity coefficients of native plant species composition among sites sampled for riparian vegetation within the riparian zone of the Serpentine River and Birrega Drain. Site codes: DH = Dog Hill; SBC = Serpentine-Birrega Confluence; LGS = Lowlands Gauging Station; CR = Coffee Rocks; HD = Horse Drink; LF = Lowlands Forest.

24 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Plant coverage

In terms of plant coverage in the riparian zone, regardless of plant-species, the two-dimensional ordination plot of Bray-Curtis similarity coefficients suggests that there was some separation among sites along both axes (Figure 9), although this separation was not strongly significant and appeared merely as a trend, as confirmed by ANOSIM (R = 0.852, P = 0.10). In terms of the ecological function of plant coverage along riparian zones, canopy cover of the overstorey, middlestorey and understorey influence stream temperature, fauna biodiversity, instream habitat, etc. (Pen 1999). The average dissimilarity between sites was 36.52; average abundances, given as percentage cover, are presented in Figure 10. From ANOVA, degraded sites had significantly more understorey coverage than natural sites (t = 6.791, df = 4, P = 0.002) and significantly less middlestorey coverage than natural sites (t = -3.714, df = 4, P = 0.021) and the difference in the average abundance of overstorey coverage between degraded and natural sites was also significant (t = -2.820, df =4, P = 0.0048), with average overstorey coverage of degraded sites being nearly 50% less than in the natural sites. When middlestorey and overstorey species (i.e. trees and shrubs) were combined, degraded sites had a lower proportion of woody plants (28.33%) compared to natural sites (63.33%) (t = -2.734, df = 10, P = 0.021).

Figure 9. Two-dimensional ordination plot of Bray-Curtis similarity coefficients of plant coverage among sites sampled for riparian vegetation within the riparian zone of the Serpentine River and Birrega Drain. Site codes: DH = Dog Hill; SBC = Serpentine-Birrega Confluence; LGS = Lowlands Gauging Station; CR = Coffee Rocks; HD = Horse Drink; LF = Lowlands Forest.

25 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

100 Degraded sites Natural sites

80

60

40 Plant coverage (%) Plantcoverage

20

0 Overstorey Middlestorey Understorey

Figure 10. Percent coverage of plants within the overstorey, middelstorey and understorey of natural and degraded sites sampled in the Serpentine River and Birrega Drain.

In-stream woody debris

Although we did not quantify in-stream habitat within the Serpentine River and Birrega Drain, natural sites, clearly had greater amounts of leaf litter, woody debris, tree fruits and large woody debris within the stream bed than the degraded sites, which was reflective of a larger proportion of woody plants in the riparian vegetation (i.e. middlestorey and overstorey species combined).

26 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Environmental variables of water quality

South-western Australia undergoes a highly seasonal climate with hot dry summers (December- February), mild autumns (March-May), cool wet winters (June-August) with gradually warming and drying springs (September-November). Environmental variables of water quality are presented in Figure 11. During the current study, temperature ranged from 11.1°C in June 2010 (Serpentine River – Lowlands Forest) to 32.3°C in February 2011 (Birrega Drain – Dog Hill). Temperatures increased from August and peaked in February. Water temperatures were as much as 7°C warmer in Birrega Drain than sites within Serpentine River and water temperatures were generally cooler in sites with larger concentrations of overstorey and middlestorey riparian vegetation. The pH varied seasonally from alkaline (>8.0) during June and August to near neutral (~7.0) during spring and summer months. All sites were generally fresh (<1000 mg/L NaCl) for most of the sampling period with the exception of Birrega Drain (Dog Hill) which became mildly brackish (>2000 mg/L NaCl) during mid-February probably due to the effects of evaporative concentration of salts during the dry summer period. Dissolved oxygen was greatest in winter and spring (62-88%) declining to 24.8-49.9% within heavily vegetated sites in summer, probably due to the lack of flow and larger concentrations of decaying plant or animal material as compared to degraded sites which were more prone to higher concentrations of algae, as indicated by super-saturated dissolved oxygen concentrations (128.4%) in the Birrega Drain (Dog Hill) during the day in February.

By February 2011, all sites were observed to have extremely low water levels and were often restricted to very small intermittent pools with much of the river bottom exposed to drying (see Figures 12-17 for examples). Total phosphorus (TP) ranged from 40 to 980 μg/L with the highest concentrations occurring in February probably due to a greatly increased concentration of decaying plant material when water levels were lowest. According to the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC & ARMCANZ 2000), the TP concentration values observed in this study were often above the ‘Trigger Value’ (=65μg/L) for physical and chemical stressors for slightly disturbed lowland river ecosystems of south-west Australia, meaning that concentrations above this value present a risk of eutrophication.

27 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Dog Hill Serpentine-Birrega Confluence Lowlands Gauging Station Coffee Rocks Horse Drink Lowlands Forest 10 pH

35 Temperature

30 8 25

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Temperature (°C) Temperature 10 5 4

0 Jun Aug Oct Dec Feb Apr Jun Aug Jun Aug Oct Dec Feb Apr Jun Aug

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0 Jun Aug Oct Dec Feb Apr Jun Aug Jun Aug Oct Dec Feb Apr Jun Aug

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µ 600

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( P Total 200

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Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Figure 11. Environmental variables within Serpentine River and Birrega Drain during the sampling period. 28 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1

2

3

Figure 12. Examples of seasonal differences in water flow at Dog Hill Gauging Station during a (1) low rainfall winter – June 2010, (2) extremely dry, hot summer – February 2011, (3) restored flows during normal to above average rainfall – 31 August 2011

29 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1

2

3

Figure 13. Changes in water flow in the Serpentine River – Birrega Drain Confluence site. Photos taken from the Serpentine River mouth facing upstream towards Lowlands: (1) June 2010, (2) February 2011, (3) August 2011

30 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1 2

3 4

5 6

Figure 14. Lowlands Gauging Station: (1) August 2010, (2) November 2010, (3) February 2011, (4) August 2011, (5) controlled livestock access, (6) pool just below and downstream from the gauging station weir which was sampled for freshwater mussels and fishes.

31 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1

2

3

Figure 15. Coffee Rocks: (1) June 2010, (2) March 2011, (3) August 2011,.

32 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1

2

Figure 16. Horse Drink: (1) February 2011, (2) August 2011,. 33 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

1

2

Figure 17. Lowlands Forest: (1) June 2010, (2) February 2011,. 34 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Summary of fish, crayfish and other fauna captures

Freshwater Fauna

A total of 132380 fish, freshwater crayfish, shrimp and tadpoles were captured during the survey of six sites in the Serpentine River and Birrega Drain in 2010/2011 (Tables 2 and 3). Of these captures, 3597 (2.71%) were native freshwater fish, 419 (0.32%) were native estuarine fish, two (0.002%) were native anadromous (migrate into rivers from the ocean to breed) fish 124661 (94.17%) were feral fish, 900 (0.68%) were native freshwater crayfish, 2578 (1.95%) were native freshwater shrimp, 25 (0.02%) were feral freshwater crayfish and 198 (0.15%) were tadpoles.

There were four species of native endemic freshwater fishes recorded during the survey (Table 2), including: Western Minnow (Galaxias occidentalis) (3208 individuals, 89.19% of native freshwater fish captured), Western Pygmy Perch (Nannoperca vittata) (220 individuals, 6.11%), Nightfish (Bostockia porosa) (164 individuals, 4.56%) and Freshwater Cobbler (Tandanus bostocki) (five individuals, 0.14%). There were two estuarine species recorded in this system: the Swan River Goby (Pseudogobius olorum) (418 individuals, 99.76% of native estuarine fish captured) and Western Hardyhead (Leptatherina wallacei) (one individual, 0.25%). There was one species of native anadromous fish, Pouched Lamprey (Geotria australis). The feral fish species captured consisted of the Eastern Gambusia (Gambusia holbrooki) (124343 individuals, 99.75% of feral fishes captured) and Goldfish (Carassius auratus) (318 individuals, 0.25%) (Tables 2 and 3). While the Eastern Gambusia was widespread, the Goldfish was restricted in distribution.

The native freshwater crayfishes were the Gilgie (Cherax quinquecarinatus) (885 individuals, 98.33% of the native freshwater crayfishes captured) and the Marron (15 individuals, 1.67%). The feral eastern Australian Yabby (Cherax destructor) was also recorded (25 individuals) (Table 3).

Other non-targeted species captured included two species of native aquatic reptiles: the Long-neck Turtle (Chelodina oblonga) (38 individuals in fyke nets) and, observed during electro- fishing but not in fyke nets, the Western Tiger Snake (Notechis scutatus) (five individuals); 198 individual tadpoles, which were not identified to species, but adults seen in the sites included Motorbike Frog (Litoria moorei), Slender Tree Frog (Litoria adelaidensis) and Squelching Froglet (Crinia insignifera); and one native Pacific Black Duck (Anas superciliosa) which accidentally entered a fyke net. All these bycatch or observed animals were released un-harmed at the site of capture.

35 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

A number of species of freshwater macroinvertebrates were also present in the fyke nets, which included caddisfly larvae (Trichoptera), Diving Beetles (Coleoptera: Dytiscidae), Dragonfly Larvae (Odonta: Anisoptera), Damselfly Larvae (Odonta: Zygoptera), the introduced freshwater snail (Gastropoda: Physidae: Physa sp.), Leeches (Hirudinea), Freshwater Worms (Oligochaeta), Water Spiders (Arachnida); Backswimmers (Insecta: Hemiptera: Notonectidae), Water Scorpions (Insecta: Hemiptera: Nepidae) and larval midges (Insecta: Diptera: Chironomidae and Ceratopogonidae) (see Davis & Christidis 1999 for descriptions). No further analyses of species other than fishes and freshwater crayfishes will be presented.

Table 2. Total number of fishes captured in the Serpentine River and Birrega Drain (June 2010 – August 2011). Species codes: BP – Nightfish; Go – Western Minnow; Nv – Western Pygmy Perch; Tb – Freshwater Cobbler; Ga – Pouched Lamprey; Lw – Western Hardyhead; Po – Swan River Goby; Ca – Goldfish; Gh – Eastern Gambusia. Site codes: LF – Lowlands Forest; HD – Horse Drink; CR – Coffee Rocks; LGS – Lowlands Gauging Station; SBC – Serpentine-Birrega Confluence; DH – Dog Hill Gauging Station. Native freshwater fishes Native Native estuarine FERAL fishes Diadromous fishes fishes Site Bp Go Nv Tb Ga Lw Po Ca Gh LF 29 446 13 1 0 0 23 1 1216 HD 28 353 51 0 1 0 33 0 427 CR 25 336 16 0 0 0 44 1 1418 LGS 77 1942 65 1 1 0 190 110 4925 SBC 2 129 51 3 0 0 120 7 1896 DH 3 2 24 0 0 1 8 199 114461 Totals 164 3208 220 5 2 1 418 318 124343

Table 3. Total number of freshwater crayfishes and other fauna captured in the Serpentine River and Birrega Drain (June 2010 – August 2011). Species codes: Cc – Smooth Marron; Cq – Gilgie; Pa – South-west Glass Shrimp; Co – Longneck Turtle; Ns – Western Tiger Snake; As – Pacific Black Duck; Cd – Yabbie. Site codes: LF – Lowlands Forest; HD – Horse Drink; CR – Coffee Rocks; LGS – Lowlands Gauging Station; SBC – Serpentine-Birrega Confluence; DH – Dog Hill Gauging Station. Native Native Native reptiles Native Native FERAL freshwater freshwater freshwater amphibians waterfowl crayfishes crayfishes shrimp Site Cc Cq Pa Co Ns Tadpoles As Cd LF 3 255 398 1 1 103 0 0 HD 4 117 311 5 0 40 0 0 CR 3 124 24 2 1 41 0 0 LGS 4 218 64 10 2 9 0 0 SBC 0 129 1781 20 0 2 1 7 DH 1 42 0 0 1 3 0 16 Totals 15 885 2578 38 5 198 1 23

36 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Patterns of fish migration

Movement patterns of the Western Minnow, Nightfish, Swan River Goby, Western Pygmy Perch and Eastern Gambusia are illustrated in Figures 18-22 Due to the paucity of Freshwater Cobbler captures, no migration patterns were apparent. Two individual juvenile Pouched Lampreys were captured in fyke nets moving downstream at Horse Drink and Lowlands Gauging Station during August 2010, suggesting that the study area and/or areas upstream in the Serpentine River may be a spawning ground for the species.

From fyke net captures, movement strength of native freshwater fishes was strongest during winter and early spring, which is best illustrated by the considerable number of Western Minnows moving upstream in many of the sites during those periods and a larger number of upstream-moving Western Pygmy Perches captured during August 2011 at Horse Drink when compared to other months. These species are known to spawn during winter and spring and this movement most likely reflected a spawning migration as suggested by the large proportion of gravid females and sexually ripe males during these sampling periods.

In September 2010, when water levels were receding and temperatures were increasing, a mass downstream movement of Western Minnows and Nightfishes was observed at most sampling sites, with a large concentration of fishes appearing at Lowlands Gauging Station during that time. A relatively large concentration of smaller (<50mm TL), presumably immature minnows was also observed at the Serpentine – Birrega Confluence. These data therefore strongly indicate this study section and probably other areas upstream in the Serpentine River provide breeding and nursery habitat for these native freshwater fishes.

Upstream movement of Swan River Gobies was relatively strong at Serpentine – Birrega Confluence and Lowlands Gauging Station during November 2010 and these fishes were gravid with eggs, suggesting the movement was related to spawning. Eastern Gambusia captures peaked during summer months and downstream movement was generally stronger, although this species is generally under-represented in fyke net captures as it is not known to migrate strongly. Furthermore, being a live-bearing species, Eastern Gambusia movement is not generally associated with spawning migrations as opposed to the native freshwater fishes of the region. Goldfish were generally restricted to sites below Lowlands Gauging Station and no strong movement patterns were observed during this study.

37 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Western Minnow 1000 Lowlands Gauging Station 100 Serpentine - Birrega Confluence 800 80

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Figure 18. Upstream and downstream migration of Western Minnow (Galaxias occidentalis) in the Serpentine River and Birrega Drain sites. 38 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Nightfish 50 Serpentine - Birrega Confluence Lowlands Gauging Station 20 18 40 16 14 30 12 10 20 8 6 4 10 2 0 0

20 20 Coffee Rocks Horse Drink 18 18 16 16 14 14 12 12 10 10 8 8

6 6 Number of fish of Number

4 4

2 2

0 0

20 Lowlands Forest 18 June 2010 August 2010 August 2011 January 2011February 2011 16 SeptemberNovember 2010 2010 14 Month 12 10 8 Upstream movement 6 Downstream movement 4 2 0

June 2010 August 2010 August 2011 January 2011February 2011 September November2010 2010 Month

Figure 19. Upstream and downstream migration of Nightfish (Bostockia porosa) in the Serpentine River and Birrega Drain sites. 39 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Western Pygmy Perch

30 30 Serpentine - Birrega Confluence Lowlands Gauging Station

25 25

20 20

15 15

10 10

5 5

0 0

30 Coffee Rocks 30 Horse Drink 25 25

20 20

15 15

10 10 Number of fish of Number

5 5

0 0

June 2010 30 August 2010 August 2011 Lowlands Forest January 2011February 2011 September November2010 2010 25 Month 20 Upstream movement 15 Downstream movement

10

5

0

June 2010 August 2010 August 2011 January 2011February 2011 September November2010 2010 Month

Figure 20. Upstream and downstream migration of Western Pygmy Perch (Nannoperca vittata) in the Serpentine River and Birrega Drain sites. 40 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Swan River Goby

100 Serpentine - Birrega Confluence 100 Lowlands Gauging Station

80 80

60 60

40 40

20 20

0 0

100 100 Coffee Rocks Horse Drink

80 80

60 60

40 40 Number of fish of Number

20 20

0 0

100 Lowlands Forest

June 2010 August 2010 August 2011 January 2011February 2011 80 September November2010 2010

Month 60

Upstream movement 40 Downstream movement

20

0

June 2010 August 2010 January 2011 September 2010November 2010

Month

Figure 21. Upstream and downstream migration of Swan River Goby (Pseudogobius olorum) in the Serpentine River and Birrega Drain sites. 41 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Eastern Gambusia 700 Lowlands Gauging Station 700 Serpentine - Birrega Confluence 650 650 600 600 550 550 500 500 450 450 400 400 350 350 300 300 250 250 200 200 150 150 100 100 50 50 0 0

700 Coffee Rocks 700 Horse Drink 650 650 600 600 550 550 500 500 450 450 400 400 350 350 300 300 250 250 Number of fish of Number 200 200 150 150 100 100 50 50 0 0

850 Lowlands Forest 800 750 June 2010 700 August 2010 August 2011 January 2011February 2011 650 November 2010 600 September 2010 550 500 Month 450 400 350 Upstream movement 300 Downstream movement 250 200 150 100 50 0

June 2010 August 2010 August 2011 January 2011February 2011 SeptemberNovember 2010 2010 Month

Figure 22. Upstream and downstream migration of Eastern Gambusia (Gambusia holbrooki) in the Serpentine River and Birrega Drain sites. 42 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution patterns and population structure of native fishes

The most common of the four freshwater fish species captured was the widespread Western Minnow. The ambush predator Nightfish and the Western Pygmy Perch however, were captured less frequently and in smaller numbers. In general, native freshwater fishes were more common in the Serpentine River than Birrega Drain which was probably due to the availability of complex habitats housing more woody debris, overhanging and in-stream vegetation on a variety of substrates which has been shown to support prey items such as macroinvertebrates and terrestrial insects and support favourable temperature regimes and spawning habitats (e.g. Pen 1999).

Densities of native freshwater fishes (Tables 4 and 5) captured by electro-fishing ranged from 0.034 to 0.235 Western Minnows/m2, 0.018 to 0.038 Nightfish/m2 and up to 0.015 Western Pygmy Perch/m2 within natural sites. Within degraded sites of the Birrega Drain densities ranged from 0.005 to 0.088 Western Minnows/m2, 0.003 to 0.099 Nightfish/m2 and 0.003 to 0.180 Western Pygmy Perch/m2. Within the Lowlands Gauging Station Site of the Serpentine River however, native freshwater fishes became more concentrated during spring with densities of 0.424-0.920/m2, 0.099/m2 and 0.5/m2 for Western Minnow, Nightfish and Western Pygmy Perch, respectively. This probably resulted from a mass migration of fishes from further upstream as water supplies began to dwindle in September and fishes were moving downstream to seek refuge in deeper waters, but could have also been due to the gauging station weir acting as a barrier to prevent upstream migration of fishes as flows ceased. Within the Birrega Drain, native freshwater fishes (Nightfish and Western Pygmy Perch) were limited to cooler waters within deeper pools and rocky overhangs which also contained reeds and overhanging grassy habitats and Western Minnows were only found at the base of shallow waterfalls associated with the weir and turbulent riffles at Dog Hill Gauging Station. Statistically, there were no differences in densities among native freshwater fishes in any of the capture sites. Densities of the two feral fish species captured became most concentrated during the spring and summer months when nutrients and water temperatures were greatest.

Although there were no statistical differences in catch per unit effort of native freshwater fishes in fyke nets, (i.e. number of fishes captured per fyke unit), native freshwater fishes tended to be more abundant in natural sites than degraded sites with the exception of Lowlands Gauging station where a large concentration of fishes were captured in September and November 2010 (Tables 6 and 7). The greater number of fishes captured within natural sites during winter periods is probably again indicative of favourable habitats which support dietary and spawning activities.

43 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

A nocturnal species, Freshwater Cobbler was observed moving up and down the riffle zone near the bridge (Junior, pers. comm.), possibly as a foraging activity (Beatty et al. 2006). In the current study, very few were recorded within the sampling sites (Table 2 and Figure 23). Several individuals were captured in fyke nets in late winter and early spring within the Serpentine River – Birrega Drain Confluence, Lowlands Gauging Station and Lowlands Forest sites (Table 2). In an additional site in the Serpentine River, a resident population within a deep pool near Rapids Rd Bridge, was found to house several size classes, probably representing a self-maintaining population (Figure 24). This population was heavily burdened with Lernaea sp., an introduced parasitic copepod, presumably originating from the introduction of feral Goldfish (see Appendix I).

The Swan River Goby (also known as Blue-spot Goby) is a common and widespread species found throughout south-western and south-eastern Australia, primarily in estuaries but is also found inland from estuaries in completely fresh rivers and lakes. This typically estuarine species has become increasingly common in salinised systems such as the Blackwood River (Morgan et al. 2003). Although not recorded in the current survey, a number of species, such as the South-west Goby (Afurcagobius suppositus), Black Bream (Acanthopagrus butcheri) and Sea Mullet (Mugil cephalus) may also, at least seasonally, utilise the lower reaches of the system. Rupert Richardson recalls large numbers of Sea Mullet being present in the Birrega Drain up to Lowlands Gauging Station during early spring. The Swan River Goby appears to breed within the Serpentine River with favourable habitats including sandy bottoms and rocky crevices. The species was found at every site within the study area (Table 2). Fishes captured in summer (November – December) were gravid with eggs.

The Pouched lamprey is a widespread anadromous species which inhabits marine environments for much of its life before migrating inland from estuaries upstream into freshwater rivers where it spawns and dies. Using a rasping toothed suctorial disc, adults feed on the body fluids of larger marine fishes as ectoparasites. The brown larval or ‘ammocoete’ stage lives in sandy sediments where it filter feeds for several years before metamorphosis to the vibrantly coloured aqua blue coloured juvenile stage, which closely resembles the adult morphology. Listed as a Priority 1 species (DEC 2011), it has become increasingly uncommon throughout much of its former range within south-western Australia believed to be due to salinisation and loss of shading riparian vegetation. Juveniles were captured in fyke nets moving downstream during August 2010 at Horse Drink and Lowlands Gauging Station, suggesting the species breeds within the Lowlands Bush Forever site. Lampreys are an important food source for marine birds, such as Wandering Albatross (Diomedea exulans), and other freshwater fauna such as Marron (Gill, pers. comm.; see marron section). Unlike other

44 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH fishes, un-natural barriers such as weirs are less of an obstacle since the species is able to climb using its suctorial disc.

The population structure and distribution pattern of the Western Minnow, Western Pygmy Perch, Nightfish and Swan River Goby within the Serpentine River and Birrega Drain is presented in Figures 24-47 below. Generally speaking, native freshwater fishes were represented by multiple cohorts which demonstrate that the species are probably utilizing Lowlands and possibly other upstream areas of the Serpentine as a spawning ground.

Table 4. Average densities (No./m2) of fishes and crayfishes captured during electro-fishing in ‘Degraded’ sites within the Serpentine River an Birrega Drain study area. Site Date Native Freshwater Native Native Feral fishes Feral Fishes euryhaline freshwater crayfi fishes crayfishes shes Bp Go Nv Po Cc Cq Ca Gh Cd Dog Hill Jun 2010 0 0 0 0 0 0.011 0.002 0.460 0 Oct 2010 0 0 0 0 0 0 0 0 0 Nov 2010 0.003 0 0 0.018 0 0.012 0.082 41.108 0.003 Jan 2011 0.005 0 0.011 0 0 0.153 0.806 975.556 0 Feb 2011 0 0 0.056 0.011 0 0.031 0.528 ~1000 0.069 Aug 2011 0 0.005 0 0.014 0 0 0.003 8.611 0.056 Serpentine – Jun 2010 0 0.022 0 0 0 0.078 0 0.591 0 Birrega Confluence Oct 2010 0 0.026 0.003 0 0 0.034 0 0.128 0 Nov 2010 0 0.088 0.180 0.008 0 0.016 0 0.604 0 Jan 2011 0 0 0 0 0 0 0 ~10 0 Feb 2011 DRY DRY DRY DRY DRY Aug 2011 ------Lowlands Jun 2010 0 0 0 0.008 0 0.072 0 1.649 0 Gauging Station Oct 2010 0 0.424 0 0.022 0 0.065 0 0.857 0 Nov 2010 0.099 0.920 0.5 0.426 0.032 0.334 0.012 11.886 0 Jan 2011 0 0 0 0 0 0 0.656 4.833 0 Feb 2011 ------0.023 ------Aug 2011 ------

45 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Table 5. Average densities (No./m2) of fishes and crayfishes captured during electro-fishing in ‘Natural’ sites within the Serpentine River study area. Species codes: Bp = Nightfish; Go = Western Minnow; Nv = Western Pygmy Perch; Po = Swan River Goby; Cc = Smooth Marron; Cq = Gilgie; Ca = Goldfish; Gh = Eastern Gambusia; Cd = Yabby. Site Date Native Freshwater Native Native Feral fishes Feral Fishes eryhaline freshwater crayfi fishes crayfishes shes Bp Go Nv Po Cc Cq Ca Gh Cd Coffee Rocks Jun 2010 0 0.034 0 0 0.033 0.129 0 0.034 0 Oct 2010 0 0 0 0 0 0 0 0 0 Nov 2010 0 0.036 0 0 0 0.053 0 0.489 0 Jan 2011 0 0 0 0 0 0 0 ~5 0 Feb 2011 ------Aug 2011 ------Horse Drink Jun 2010 0 0.109 0 0 0.006 0.096 0 0.558 0 Oct 2010 0.018 0.043 0 0 0.006 0.105 0 0.169 0 Nov 2010 0 0.037 0 0 0.014 0.014 0 0.068 0 Jan 2011 0 0 0 0 0 0 0 ~5 0 Feb 2011 ------Aug 2011 ------Lowlands Jun 2010 0 0.235 0 0 0 0.119 0 0.298 0 Forest Oct 2010 0.038 0.197 0 0 0 0.692 0 0.159 0 Nov 2010 0 0.117 0.015 0 0.023 0.189 0 1.25 0 Jan 2011 0 0 0 0 0 0 0 ~5 0 Feb 2011 ------

46 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

0 0 0 0 0 0 0 0 3.5 0 0 0 0 0 ------

--- Cd Feral crayfishes

in ‘Degraded’ in ‘Degraded’

2

0.5 96 43 211 135.5 5 12 51.5 482 207 2 11.5 0 0 ------

--- Gh

0 2 9 0 0 1.5 0 0 1.5 0 0.5 0 0.5 1 ------

--- Ca Feral fishes netting yke

1 13.5 26 17 11.5 0 2 1 3 0.5 0 1.5 0 0 ------

--- Cq

0 0 0 0.5 0 0 0 0 0 0 0 0 0 0 ------

--- Cc freshwater Native crayfishes

captured during overnight f overnight during captured

1.5 13 10 62.5 7 0 1 1 54 3 1 0 0 0 ------

--- Po Native eryhaline fishes

0 0.5 1.5 1.5 0.5 0 0 0 0 0 7 0 0 0 ------

--- Nv

30 4.5 8.5 107 730.5 16 6 17.5 5 0 0 25.5 0.5 0 ------

--- Go

) of fishes) and crayfishes

0.5 1.5 1.5 8 20 0.5 0.5 0 0 0 0 0.5 0 0 ------

--- Bp Fishes Freshwater Native CPUE (

2010 2010

Aug 2011 Feb 2011 Jan 2011 Nov 2010 Sep 2010 Aug Jun 2010 Aug 2011 Feb 2011 Jan 2011 Nov 2010 Sep 2010 Aug 2010 Jun 2010 Aug 2011 Feb 2011 Jan 2011 Nov 2010 Sep Aug 2010 Jun 2010

Date

effort unit per catch

Birrega Birrega

–

Average

.

6

Lowlands Gauging Station Gauging Lowlands

Serpentine Serpentine Confluence

Dog Hill

Site Table area. study Drain Birrega an River Serpentine the within sites

47 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cd crayfishes Feral

7 431.5 0 72 0 3.5 1.5 10 60 37.5 54.5 0 0 1 9 335.5 148 29.5 1.5 1.5 3 Gh

in ‘Natural’ sites within the the within sites in ‘Natural’

0 0 0 0 0 0.5 0 0 0 1.5 0 0.5 0 0.5 0 0 0 0 0 0.5 0 Ca Feral fishes

4.5 19 18.5 24.5 7 1 4 6 4 6.5 9.5 14 2 3 1 21 21 4.5 0 1.5 4 Cq

netting fyke

.5

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.5 Cc freshwater Native crayfishes

5

0 0 3. 8 0 0 0 1.5 0 1.5 5.5 7 0 0.5 0.5 2.5 3.5 4.5 8.5 0.5 2 Po Native Native eryhaline fishes

0 0 0 1 3.5 1 0 20.5 0 0.5 1.5 0.5 3 0 1 0 0.5 5 1 0 0.5 Nv

3.5 0 13 31 61 42 32 2 0 8 44 27.5 20 62 5.5 4.5 39.5 23.5 49 8 37.5 Go

of fishes and crayfishes captured during during captured crayfishes and fishes of

Bp = Nightfish; Go = Western Minnow; Nv = Western Pygmy Perch; Po = Swan Swan = Po Perch; Pygmy Western = Nv Minnow; Western = Go Nightfish; = Bp

)

1.5 0 0 6 0 1.5 1.5 2.5 0 0 0 8.5 2 0 0.5 0 3.5 2 5 0.5 1 Bp Fishes Freshwater Native CPUE (

2010 2010 2010

Aug 2011 Feb 2011 Jan 2011 Nov 2010 Sep Aug 2010 Jun 2010 Aug 2011 Feb 2011 Jan 2011 Nov 2010 Sep Aug 2010 Jun 2010 Aug 2011 Feb 2011 Jan 2011 Nov 2010 Aug 2010 Sep Jun 2010

Date

catch per unit effort unit per catch

Average

7.

Lowlands Forest

Horse Drink Horse

Coffee Rocks Coffee

Site Table Serpentine River study area. Species codes: Yabby. = Cd Gambusia; Eastern = Gh Goldfish; = Ca Gilgie; = Cq Marron; Smooth = Cc Goby; River

48 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution and Population structure of Freshwater Cobbler (Tandanus bostocki)

Serpentine River

0 10 20 Km

This study (Present) Davis et al. 1988

Figure 23. Distribution of Freshwater Cobbler (Tandanus bostocki) within the Serpentine River Catchment, South-Western Australia. 49 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Table 8. Total Length (TL), sex and reproductive status of Freshwater Cobbler (Tandanus bostocki) captured within the Serpentine River sites. Date Site TL (mm) Sex Movement 15 August 2010 Lowlands Forest 160 Downstream 30 September 2010 Lowlands Gauging Station 75 Downstream 30 September 2010 Serpentine – Birrega 331 Female Upstream Confluence 30 August 2011 Serpentine – Birrega 310 Male Upstream Confluence

30 August 2011 Serpentine – Birrega 315 Male Upstream Confluence

Rapids Road

Downstream movement 4 June 2010 Upstream Movement

3

2

1

0 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

4 August 2010

3

2

1 Number of fishes 0 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

4 February 2011

3

2

1

0 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 Total length (mm)

Figure 24. Length-frequency histograms of Freshwater Cobbler (Tandanus bostocki) at Rapids Road Bridge pool. 50 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution and Population structure of Western Minnow (Galaxias occidentalis)

Perth

South-western Australia Serpentine River

0 10 20 Km

Klunzinger, unpublished data This study (Present) This study (Absent) Davis et al. 1988 Morgan, unpublished data

Figure 25. Distribution of Western Minnow (Galaxias occidentalis) within the Serpentine River Catchment, South-Western Australia.

51 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine - Birrega Confluence

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 20 30 40 50 60 70 80 90 100 110 120 130 140 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 0 15 30 45 60 75 90 105 120 135 Total length (mm) Total length (mm)

Figure 26. Length-frequency histograms of Western Minnow (Galaxias occidentalis) within the Serpentine River – Birrega Drain Confluence. 52 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

40 June 2010 40 November 2010

30 30

20 20

10 10

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135

40 August 2010 40 January 2011 30 30

20 20

10 10

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135

40 September 2010 40 February 2011

Number of fishes 30 30

20 20

10 10

0 0 15 30 45 60 75 90 105 120 135 20 30 40 50 60 70 80 90 100 110 120 130 140

40 October 2010 40 August 2011

30 30

20 20

10 10

0 0 15 30 45 60 75 90 105 120 135 0 15 30 45 60 75 90 105 120 135 Total length (mm) Total length (mm)

Figure 27. Length-frequency histograms of Western Minnow (Galaxias occidentalis) at Lowlands Gauging Station.

53 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 20 30 40 50 60 70 80 90 100 110 120 130 140 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 0 15 30 45 60 75 90 105 120 135 Total length (mm) Total length (mm)

Figure 28. Length-frequency histograms of Western Minnow (Galaxias occidentalis) at Coffee Rocks.

54 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

25 25 June 2010 November 2010 20 20

15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 25 25 August 2010 20 20 January 2011

15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 25 25 September 2010 20 20 February 2011 Number of fishes 15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 20 30 40 50 60 70 80 90 100 110 120 130 140 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 15 30 45 60 75 90 105 120 135 0 15 30 45 60 75 90 105 120 135 Total length (mm) Total length (mm)

Figure 29. Length-frequency histograms of Western Minnow (Galaxias occidentalis) at Horse Drink.

55 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

30 30 June 2010 November 2010 25 25 20 20 15 15 10 10 5 5 0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135 30 30 August 2010 25 25 January 2011 20 20 15 15 10 10 5 5 0 0 15 30 45 60 75 90 105 120 135 15 30 45 60 75 90 105 120 135

30 September 2010 30 25 25 February 2011

Number of fishes 20 20 15 15 10 10 5 5 0 0 15 30 45 60 75 90 105 120 135 20 30 40 50 60 70 80 90 100 110 120 130 140 30 30 25 October 2010 25 August 2011 20 20 15 15 10 10 5 5 0 0 15 30 45 60 75 90 105 120 135 0 15 30 45 60 75 90 105 120 135 Total length (mm) Total length (mm)

Figure 30. Length-frequency histograms of Western Minnow (Galaxias occidentalis) at Lowlands Forest.

56 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution and Population structure of Western Pygmy Perch (Nannoperca vittata)

Perth

South-western Serpentine River Australia

0 10 20 Km

This study (Present) Davis et al. 1988 Morgan, unpublished data

Fig 31. Distribution of Western Pygmy Perch (Nannoperca vittata) within the Serpentine River Catchment, South-Western Australia.

57 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine - Birrega Confluence

30 30 June 2010 November 2010 25 25 20 20 15 15 10 10 5 5 0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 30 30 August 2010 25 25 January 2011 20 20 15 15 10 10 5 5 0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 30 30 September 2010 25 25 February 2011

Number of fishes 20 20 15 15 10 10 5 5 0 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 30 30 25 October 2010 25 August 2011 20 20 15 15 10 10 5 5 0 0 10 20 30 40 50 60 70 15 30 45 60 Total length (mm) Total length (mm)

Fig32. Length-frequency histograms of Western Pygmy Perch (Nannoperca vittata) in the Serpentine River - Birrega Drain Confluence. 58 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 70 15 30 45 60 Total length (mm) Total length (mm)

Fig 33. Length-frequency histograms of Western Pygmy Perch (Nannoperca vittata) at Lowlands Gauging Station. 59 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 70 15 30 45 60 Total length (mm) Total length (mm)

Figure 34. Length-frequency histograms of Western Pygmy Perch (Nannoperca vittata) at Coffee Rocks. 60 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 70 15 30 45 60 Total length (mm) Total length (mm)

Figure 35. Length-frequency histograms of Western Pygmy Perch (Nannoperca vittata) at Horse Drink. 61 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

20 20 June 2010 November 2010 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 August 2010 January 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 7010 20 30 40 50 60 70 20 20 September 2010 February 2011 15 15 Number of fishes

10 10

5 5

0 0 10 20 30 40 50 60 70 10 20 30 40 50 60 70 20 20 October 2010 August 2011 15 15

10 10

5 5

0 0 10 20 30 40 50 60 70 15 30 45 60 Total length (mm) Total length (mm)

Figure 36. Length-frequency histograms of Western Pygmy Perch (Nannoperca vittata) at Lowlands Forest. 62 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution and Population structure of Nightfish (Bostockia porosa)

Serpentine River

0 10 20

Km

This study (Present) Davis et al. 1988

Figure 37. Distribution of Nightfish (Bostockia porosa) within the Serpentine River

Catchment, South-Western Australia.

63 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine - Birrega Confluence

15 15 June 2010 November 2010

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 August 2010 January 2011 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 September 2010 February 2011

Number of fishes 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 October 2010 August 2011

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 15 30 45 60 75 90 105 120 Total length (mm) Total length (mm)

Figure 38. Length-frequency histograms of Nightfish (Bostockia porosa) within the Serpentine River – Birrega Drain Confluence. 64 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

15 15 June 2010 November 2010

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 August 2010 January 2011 10 10

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0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 September 2010 February 2011

Number of fishes 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 October 2010 August 2011

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 15 30 45 60 75 90 105 120 Total length (mm) Total length (mm)

Figure 39. Length-frequency histograms of Nightfish (Bostockia porosa) within at Lowlands Gauging Station. 65 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

15 15 June 2010 November 2010

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 August 2010 January 2011 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 September 2010 February 2011

Number of fishes 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 October 2010 August 2011

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 15 30 45 60 75 90 105 120 Total length (mm) Total length (mm)

Figure 40. Length-frequency histograms of Nightfish (Bostockia porosa) within at Coffee Rocks.

66 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

15 15 June 2010 November 2010

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 August 2010 January 2011 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 September 2010 February 2011

Number of fishes 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 October 2010 August 2011

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 15 30 45 60 75 90 105 120 Total length (mm) Total length (mm)

Figure 41. Length-frequency histograms of Nightfish (Bostockia porosa) within at Horse Drink.

67 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

15 15 June 2010 November 2010

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 August 2010 January 2011 10 10

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0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 September 2010 February 2011

Number of fishes 10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 15 15 October 2010 August 2011

10 10

5 5

0 0 20 30 40 50 60 70 80 90 100 110 120 15 30 45 60 75 90 105 120 Total length (mm) Total length (mm)

Figure 42. Length-frequency histograms of Nightfish (Bostockia porosa) within at Lowlands Forest.

68 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH Distribution and Population structure of Swan River Goby (Pseudogobius olorum)

Perth

South-western Serpentine River Australia

0 10 20 Km

This study (Present) Morgan, unpublished data

Figure 43. Distribution of Swan River Goby (Pseudogobius olorum) within the Serpentine River Catchment, South-Western Australia.

69 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine-Birrega Confluence

60 60 June 2010 November 2010 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 August 2010 January 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 February 2011 September 2010 50 45 Number of fishes 40 30 30 20 15 10 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 October 2010 August 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60

Total length (mm) Total length (mm)

Figure 44. Length-frequency histograms of the Swan River Goby (Pseudogobius olorum) at Serpentine River-Birrega Drain Confluence 70 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

60 60 November 2010 June 2010 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 August 2010 January 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 September 2010 February 2011 50 45 Number of fishes 40 30 30 20 15 10 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 October 2010 August 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 45. Length-frequency histograms of the Swan River Goby (Pseudogobius olorum) at Lowlands Gauging Station 71 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

60 60 November 2010 June 2010 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 August 2010 January 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 September 2010 February 2011 50 45 Number of fishes 40 30 30 20 15 10 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 October 2010 August 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 46. Length-frequency histograms of the Swan River Goby (Pseudogobius olorum) at Coffee Rocks 72 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

60 60 November 2010 June 2010 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 August 2010 January 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 September 2010 February 2011 50 45 Number of fishes 40 30 30 20 15 10 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 October 2010 August 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 47. Length-frequency histograms of the Swan River Goby (Pseudogobius olorum) at Horse Drink 73 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

60 60 November 2010 June 2010 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 August 2010 January 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 September 2010 February 2011 50 45 Number of fishes 40 30 30 20 15 10 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 60 60 October 2010 August 2011 45 45

30 30

15 15

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 48. Length-frequency histograms of the Swan River Goby (Pseudogobius olorum) at Lowlands Forest 74 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution, movement patterns and population structure of freshwater crayfishes

All 11 native freshwater species of south-western Australia are endemic to the region (Austin & Knott 1996, Horwitz & Adams 2000, Morgan et al. 2011) and freshwater crayfish are known to play important roles in the structure and function of aquatic ecosystems. The Gilgie is one of the most widespread of these species, found in nearly every freshwater habitat within the southwest including ephemeral wetlands, streams and major rivers (Austin & Knott 1996; Beatty et al. 2005a). The Gilgie was very widespread in both the Serpentine River and Birrega Drain, being found in all sites that were surveyed. Movement was strongest in the spring and summer months, which may have been related to breeding, seeking refuge from receding water levels or food availability, although the movement pattern of this species has not previously been examined in detail. Both systems housed self-sustaining populations of this species as indicated by their widespread distribution, high abundances, and the relatively wide size range including juvenile individuals and older age classes (Figures 49-55) (see Beatty et al. 2005a).

The ability of the Gilgie to burrow into the water table during the summer dry periods has facilitated the use of seasonally inundated habitats. The species is also known to have a life- history strategy that allows it to rapidly re-colonise habitats, such as potentially breeding multiple times a year (Beatty et al. 2005a).

75 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

30 30 Serpentine-Birrega Confluence Lowlands Gauging Station

25 25

20 20

15 15

10 10

5 5

0 0

30 30 Coffee Rocks Horse Drink 25 25

20 20

15 15

10 10 Number of crayfish of Number 5 5

0 0

40 June 2010 Lowlands Forest August 2010 August 2011 January 2011February 2011 September November2010 2010

30 Month

Upstream movement 20 Downstream movement

10

0

June 2010 August 2010 August 2011 January 2011February 2011 September November2010 2010

Month

Figure 49. Upstream and downstream migration of Giligie (Cherax quinquecarinatus) in the Serpentine River and Birrega Drain sites. 76 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

Figure 50. Distribution of the Gilgie (Cherax quinquecarinatus) within the Serpentine River Catchment, South-Western Australia. N.B. The only information available was from this study, circled in green.

77 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine-Birrega Confluence

25 25 June 2010 November 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 August 2010 January 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 September 2010 February 2011 20 20 15 Number of crayfishes 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 Orbital carapace length (mm) Orbital carapace length (mm)

Figure 51. Length-frequency histograms of the Gilgie (Cherax quinquecarinatus) within the Serpentine River – Birrega Drain Confluence. 78 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

25 25 June 2010 November 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 January 2011 August 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 September 2010 February 2011 20 20 15 Number of crayfishes 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 Orbital carapace length (mm) Orbital carapace length (mm)

Figure 52. Length-frequency histograms of the Gilgie (Cherax quinquecarinatus) at Lowlands Gauging Station. 79 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

25 25 June 2010 November 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 January 2011 August 2010 20 20

15 15

10 10

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0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 September 2010 February 2011 20 20 15 Number of crayfishes 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 Orbital carapace length (mm) Orbital carapace length (mm)

Figure 53. Length-frequency histograms of the Gilgie (Cherax quinquecarinatus) at Coffee Rocks.

80 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

25 25 June 2010 November 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 August 2010 January 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 September 2010 February 2011 20 20 15 Number of crayfishes 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 Orbital carapace length (mm) Orbital carapace length (mm)

Figure 54. Length-frequency histograms of the Gilgie (Cherax quinquecarinatus) at Horse Drink.

81 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

25 25 November 2010 June 2010 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 August 2010 January 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 September 2010 February 2011 20 20 15 Number of crayfishes 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 25 25 October 2010 August 2011 20 20

15 15

10 10

5 5

0 0 0 10 20 30 40 50 0 10 20 30 40 50 Orbital carapace length (mm) Orbital carapace length (mm)

The Marron was recorded at four of the survey sites in the Serpentine River, which includedFigure 55.Lowlands Length -Gaugingfrequency Station,histograms Coffee of the Rocks,Gilgie (HorseCherax Drink quinquecarinatus and Lowlands) at LowlandsForest. Forest. 82 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Additionally, a single Marron was seen exiting a small, visually turbid green pool during a survey of freshwater mussels near the Dog Hill Gauging Station in March 2011 (Figure 56). The species generally relies on permanent habitat for survival. Within the study area, the largest Marron were found at the Coffee Rocks site with two individual females measuring 60 and 65 mm OCL. Marron were relatively uncommon throughout the survey sites, with only a few smaller examples being captured during winter and spring 2010 (Table 9). From the few individuals that were captured, the population there probably consisted of three age classes (see growth rates in Beatty et al. 2005b) and therefore it appears to be breeding in the system. Additional survey effort would be required to confirm the sustainability of the population in that system and the other sites where it was recorded in the study.

The Smooth Marron supports an iconic inland recreational fishery and is the world’s third largest freshwater crayfish species (Morgan et al. 2011). Originating from between Harvey and west of Albany, the species has been translocated north to the Hutt River (north of Geraldton) and east to Esperance since European Arrival. Its inland range, which receives less rainfall and has been cleared of much of its original vegetation, has been reduced due to secondary salinisation and eutrophication (Morrissy 1978; de Graaf et al. 2010). Unlike smaller crayfish species, the Marron is a seasonal breeder, reproducing annually, maturing at the end of its second year of life, and has a fast growth rate (Beatty et al. 2003, 2005b, 2010a). Like most freshwater crayfishes, its diet consists largely of detritus; however, it has recently been shown to also be an opportunistic omnivore assimilating considerable amounts of animal material including Eastern Gambusia (Beatty 2006). Within Margaret River, for example, ‘Mossy-back’ or Hairy Marron (Cherax cainii) were known to feast on Pouched Lamprey (Geotria australis) once they had spawned and died. Within the recent educational film footage of ‘Freshwater Crayfishes of South-western Australia’, a Marron was observed eating a freshwater mussel (W. carteri).

The Freshwater Shrimp (also known as South-west Glass Shrimp) was recorded at four sites within the Serpentine River and one site at the Serpentine River – Birrega Drain Confluence (Figure 57). The species is endemic to south-western Australia and is found in a wide range of water bodies including freshwater and salinised lakes and rivers (Morgan et al. 2011). Little is known about its biology or ecology. The species is believed to breed during spring and summer (Beatty & Morgan, unpubl. data) and is an important dietary component of larger endemic freshwater fishes such as Freshwater Cobbler, Nightfish and Western Minnows (Morgan et al. 1998). The species may be an important cleaner or grazer of freshwater mussels and is also thought to stimulate glochidia release in W. carteri (Klunzinger 2011).

83 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

This study (Present) Davis et al. 1988

Figure 56. Distribution of Smooth Marron (Cherax cainii) within the Serpentine River Catchment, South-Western Australia. N.B. The only information available was from this study, circled in green. Photo: Simon Visser.

84 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Table 8 Orbital carapace length (OCL), sex and reproductive status of Marron captured within the Serpentine River sites. Date Site OCL (mm) Sex 10 June 2010 Horse Drink 15 Male 18 June 2010 Coffee Rocks 60 Female 18 June 2010 Coffee Rocks 65 Female 24 November 2010 Lowlands Gauging Station 27 Female 24 November 2010 Lowlands Gauging Station 20 Male 24 November 2010 Lowlands Forest 30 Male 14 January 2011 Horse Drink 32 Male 16 March 2011 Dog Hill 65 (estimated)

85 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

This study (Present) Davis et al. 1988 Morgan, unpublished data

Figure 57. Distribution of Southwest Glass Shrimp (Palaemonetes australis) within the Serpentine River Catchment, South-Western Australia.

86 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Distribution patterns population structure and eradication of feral fishes

Eastern Gambusia The Eastern Gambusia was recorded at all sites in the Serpentine River and Birrega Drain (Figure 58) and dominated the total species capture, particularly in summer when maximum densities numbered in the 100’s to 1000’s of fish/m2 (Table 2). The Eastern Gambusia captured in this study was represented by several size classes and included breeding populations of males and live-bearing females (Figures 59-64). The species is not known to be a migratory fish, so this movement was probably related to localised feeding activity rather than migration. The species has invaded the majority of the Swan Coastal catchments, including the Serpentine River (Figure 58) and in particularly disturbed habitats it dominates the fish fauna, as was found in the Birrega Drain and Lowlands Gauging Station. It is likely that the species has been found in this system since it was first introduced in the 1930s into WA for mosquito control. The Eastern Gambusia is a well known fin-nipper of south-western Australia freshwater fishes (Gill et al. 1999), which was probably responsible for the observed fin loss in juvenile Western Pygmy Perch and Western Minnows in early summer. This may be especially detrimental to the swimming ability of pygmy perches and minnows (Keleher 2011) and could have negative consequences for glochidia that may be attached to the fins of these fishes.

Photo: James Tweedley

87 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

This study (Present) Davis et al. 1988 Morgan, unpublished data

Figure 59. Distribution of Eastern Gambusia (Gambusia holbrooki) within the Serpentine River Catchment, South-Western Australia.

88 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serepntine-Birrega Confluence

50 50 June 2010 November 2010 40 40

30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 January 2011 August 2010 40 40

30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 September 2010 February 2011 40 40 Number of fishes 30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 October 2010 August 2011 40 40

30 30

20 20

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Total length (mm) Total length (mm)

Figure 60. Length-frequency histograms of the Eastern Gambusia (Gambusia holbrooki) within the Serpentine River – Birrega Drain Confluence. 89 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Gauging Station

50 50 June 2010 November 2010 40 40

30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 January 2011 August 2010 40 40

30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 September 2010 February 2011 40 40 Number of fishes 30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 October 2010 August 2011 40 40

30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 61. Length-frequency histograms of the Eastern Gambusia (Gambusia holbrooki) at

Lowlands Gauging Station. 90 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Coffee Rocks

50 50 June 2010 November 2010 40 40

30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 August 2010 January 2011 40 40

30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 September 2010 February 2011 40 40 Number of fishes 30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 October 2010 August 2011 40 40

30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 62. Length-frequency histograms of the Eastern Gambusia (Gambusia holbrooki) at Coffee

Rocks. 91 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Horse Drink

50 50 June 2010 November 2010 40 40

30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 August 2010 January 2011 40 40

30 30

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 September 2010 February 2011 40 40 Number of fishes 30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 October 2010 August 2011 40 40

30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 63. Length-frequency histograms of the Eastern Gambusia (Gambusia holbrooki) at Horse

Drink. 92 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Lowlands Forest

50 50 June 2010 November 2010 40 40

30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 August 2010 January 2011 40 40

30 30

20 20

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0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 September 2010 February 2011 40 40 Number of fishes 30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 50 50 October 2010 August 2011 40 40

30 30

20 20

10 10

0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Total length (mm) Total length (mm)

Figure 64. Length-frequency histograms of the Eastern Gambusia (Gambusia holbrooki) at Lowlands Forest. 93 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Goldfish Very few Goldfish were captured in natural sites during the sampling period and most were captured within the Birrega Drain and Lowlands Gauging Station sites (Figure 65). Average density of Goldfish was reduced from January to February 2011 (Figure 66), indicating that our sampling methods were successful in eradicating Goldfish in degraded sites. While sampling in the Birrega Drain, a turbid pool downstream from the Dog Hill Gauging Station was located and found to contain a number of fishes ranging from 58 to 202 mm TL (Figure 67). A fairly sizeable population of Goldfish was also observed in a turbid pool below Lowlands Gauging Station in January and February 2011. Following a cull of fishes from the Birrega Drain in November 2010, TL was reduced from to a range of 30 – 135 mm during these sampling periods (Figure 67). The elimination of larger individuals in November 2010 reduced the average TL from 104.8 mm to 64.4 mm and 75.1 mm TL in the subsequent sampling periods of January and February 2011 in the degraded sites. Very few Goldfish were captured during winter flows in June 2010 and August 2011.

As a result of illegal releases, Goldfish are now well established in many artificial wetlands as well as a number of lakes and rivers of south-western Australia (Morgan et al. 2004, 2011). The biology and ecology of the species within the Vasse River was examined by Morgan & Beatty (2007), who found that the population is probably the fastest and largest growing in the world. Goldfish were captured in the study area between November 2010 and February 2011 and were primarily restricted to pools within degraded sites below Lowlands Gauging Station in the Serpentine River and Birrega Drain near Dog Hill Gauging Station.

The species seems to thrive well and dominate eutrophic waters where growth is rapid and their diet is composed largely of blue-green algae (Morgan & Beatty 2007). The species is less common in the cooler, well-vegetated mesotrophic waters of the south-west. Goldfish have been responsible for the introduction of foreign disease and parasites (such as the ectoparasitic crustacean Lernea cyprinacea (Marina et al. 2008), out competing native species for food and habitat, predating native fishes and their eggs and, potentially fuelling algal blooms through re-suspension of nutrients during feeding and re-activation of blue-green algae through their intestines (Kolmakov & Gladyshev 2003), all much to the detriment of the south- west’s unique biodiversity. The tolerance to adverse environmental conditions, such as high temperatures, low dissolved oxygen and increased salinisation is partly why they are a favoured aquarium species, but is also one of the reasons why they have survived followed their introduction to the south-west (Morgan et al. 2004; Morgan & Beatty 2007).

94 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

This study (Present) Morgan, unpublished data

Figure 65. Distribution of Goldfish (Carassius auratus) within the Serpentine River Catchment, South-Western Australia.

95 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Goldfish Density Reduction 1.8

1.6 Dog Hill Lowlands Gauging Station 1.4 ) 2 1.2

1.0

0.8

0.6

Density (No. Density fish/m 0.4

0.2

0.0

June 2010 Nov 2010 Jan 2011 Feb 2011 Aug 2011

Month Figure 66. Goldfish eradication within degraded sites of the Serpentine River and Birrega Drain showing reduction in fish densities during summer 2010-2011.

96 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

20 November 2010

15

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5

0 0 50 100 150 200

20 January 2011

15

10 Number of fish of Number 5

0 0 50 100 150 200

20 February 2011

15

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5

0 0 50 100 150 200 TL (mm)

Figure 67. Length-frequency histograms of Goldfish captured in the Serpentine River and Birrega-Drain sites during summer 2010-2011. Images – Top: turbid pool in Birrega Drain, downstream from Dog Hill; Middle: Goldfish (Carassius auratus) captured during this study; Bottom: Serpentine River, pool below Lowlands Gauging Station.

97 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Yabby The Yabby is the only feral freshwater crayfish species currently known from south-western Australia. In the current study, it was recorded in Birrega Drain primarily in February 2011 (Figure 68). Figure 69 illustrates that there were at least two and possibly three age classes present (see biology of the species in Beatty et al. 2005c) suggesting this was a breeding population. Furthermore, the presence of ‘berried’ eggs attached to the pleopods of an individual female was recorded in February 2011. Originally introduced into south-western Australia in the 1930’s for aquaculture, this species has escaped into numerous wild aquatic systems in this region (Beatty et al. 2005c). Its life-history traits allow it to rapidly colonise new systems and these include: maturing in its first year of life, breeding multiple times during warmer months; burrowing to escape drought; tolerance of extreme temperatures and low dissolved oxygen; and a varied omnivorous diet (e.g. Beatty et al. 2005c, Beatty 2006). The species is known to compete with Marron (also having a similar growth rate in its first year of life) for food sources and undoubtedly competes with other endemic species when present (Beatty 2006). Lynas et al. (2002) showed that the yabby displayed aggressive dominance over Marron in laboratory trials when the two species were of similar size and body mass. Yabbies also have the potential to introduce diseases such as ‘porcelain disease’ which is caused by microsporidians Thelohania parastaci and Vavraia parastacida (Beatty 2005). Once established in a wild aquatic system, eradication of the Yabby is extremely unlikely.

98 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

0 10 20 Km

This study (Present) Morgan, unpublished data

Figure 68. Distribution of Yabby (Cherax destructor) within the Serpentine River Catchment, South-Western Australia.

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10 Dog Hill (November 2010) 8

6

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Figure 69. Length-frequency histograms of Yabby (Cherax destructor) captured within the Dog Hill Gauging Station and Serpentine River-Birrega Drain Confluence during the study.

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Distribution, abundance, population structure and glochidia host-fish of Carter’s Freshwater Mussel

Mussel distribution and abundance

Museum records indicate that Carter’s Freshwater Mussel once ranged from Moore River in the north, east to the Avon River, extending southward and westward to regions of the west coast and eastwardly along the south coast to the Kalgan River (Morgan et al. 2011; Klunzinger et al., unpublished data). Early records suggest the species may have been more widespread from the Gascoyne River (BMNH_MP_110 c.a. 1824) in the north to King George Sound (AMS_47295 and AMS_126151 c.a. 1877) with one record extending as far east as Esperance town Beach (WAM_34289 c.a. 1978) in the south. The distribution of the species within the Serpentine River catchment extends from the Serpentine Dam in the east, westward through Lowlands and southward within the Birrega Drain and bounded by tidal influence in Goegrup Lake, although the distribution of the species within Birrega Drain is not entirely known (Figure 70). Live W. carteri was found at every site apart from Lowlands Gauging Station.

101 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Perth

South-western Australia Serpentine River

Gooralong Brook

Goegrup Lake

Serpentine Dam

0 10 20

Km

Klunzinger, unpublished data This study (Present) This study (Absent) Western Australian Museum Records Australian Museum Records Davis et al. 1988 Mussel Watch WA Klunzinger (Absent), unpublished data

Figure 70. Distribution of Carter’s Freshwater Mussel (Westralunio carteri) within the Serpentine River Catchment, South-Western Australia.

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Localised population densities of freshwater mussels within the Australasian region and elsewhere is generally patchy with densities ranging from 1 to as many as 814/m2 (Walker et al. 2001). From our surveys throughout south-western Australia, where W. carteri is found, they can be locally abundant with patch densities ranging from a few individuals to as many as 250/m2, influenced strongly by the level of disturbance within the localized habitats.

Within the current study, mussel densities ranged from 1 to as many as 87 mussels/m2. Average densities within sampling sites ranged from 0.15 to 13.39 mussels/m2 (F = 2.413, df = 5, P = 0.04) (see Figure 71). Average mussel density within Horse drink was significantly greater than in Lowlands Gauging Station (13.39 vs. 0.15 mussels/m2; t = 3.189, df = 1, P = 0.027), but no other statistically significant differences between sites were observed. This difference suggests that the gauging station may be less suitable mussel habitat than Horse Drink, probably due to the greater buildup of fine sediments above and below the weir and the more favourable habitats of sandy mud, woody debris and macrophytes such as Triglochin spp. which are also favourable to potential host fishes for the glochidia of W. carteri within Horse Drink. The observed differences in mussel density between sites are probably attributed to a number of factors. Walker et al. (2001) and Strayer (2008), for example suggest that factors important to distribution and abundance of freshwater mussels include dispersal rate, habitat composition, availability of host fishes, and availability of food and potential threats from feral predators, parasites and macroinvertebrates which predate vulnerable juvenile-stage mussels.

Prior to this study in January 2010, only a few live mussels were observed at Lowlands Gauging Station (LGS), but surveys after June 2010 failed to recover any live mussels at the site. Because baseline surveys before the construction LGS were not conducted, it is difficult to determine whether the construction activity resulted in losses of W. carteri from the site or whether the presence of cattle may have also been a contributing factor, although these activities have been known to deplete hyriid colonies of freshwater mussels elsewhere (Jones & Byrne 2010). The build-up of anoxic organic debris and extremely fine, soft, unstable sediments downstream of LGS decreases the likelihood of mussel survival. The large amount of mobile sand from erosion near the Serpentine – Birrega Confluence (SBC) may have prevented the settlement of juvenile mussels and prevented a stable platform for normal adult mussel activity. Within Birrega Drain itself, mussel distribution was patchy and populations were generally clustered along the banks, often nestled amongst vegetation and tree roots within stable sandy sediments. Much of the drain was unsuitable mussel habitat due to the impenetrable nature of the solid stream bottom. The natural sites were generally more biodiverse and generally had a greater amount of leaf litter, woody debris, overhanging vegetation and canopy cover which probably buffered against temperature extremes and provided exceptional fish habitat as well as supplying adequate oxygen during higher flow periods. Between November and February 2011, much of the area within the study sites had

103 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH dried excessively to the point where mussels became exposed (Figures 72-73). Within the Birrega Drain, many mussels were found dead, which was a result of drying and/or increased predation by other animals, as was found in the Lower Helena Pipehead Dam and elsewhere within the south-west (Klunzinger et al. 2011a,b). During the same period, mussels within the natural sites were found clustered within small puddles and dug into soft mud and sand that does not collapse as mussels burrow, essentially creating ‘tubes’ which remain moist as water levels recede, all of which were alive.

21 Mussel Density ) 2 18

15

12

9

6

Average density (No. mussels/m (No. density Average 3

0

DH SBC LGS CR HD LF

Site Figure 71. Average density of freshwater mussels (Westralunio carteri) within sampling sites of the study area. Site codes: DH = Dog Hill; SBC = Serpentine – Berriga Confluence; LGS = Lowlands Gauging Station; CR = Coffee Rocks; HD = Horse Drink; LF = Lowlands Forest.

104 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Figure 72. Freshwater mussels (Westralunio carteri) exposed to drying in the Birrega Drain during February 2010. 105 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

A

B C

Figure 73. A) An area of the Serpentine River within the Horse Drink site consisting of a mostly dry river bed with small pools of receding water remaining, which contained many freshwater mussels (Westralunio carteri). The pool was excavated and found to contain >100 mussels, all alive in February 2010. Note shading from riparian vegetation. The stream bed remained moist. exposed to drying in the Birrega Drain during February 2010. B) The same area in December 2009 showing mussels burrowed in sand near tree roots and C) water level at the same tree.

106 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Mussel population structure

Mean MHI was 60.0%, which is within the reported range for W. carteri (60-70%; McMichael & Hiscock 1958). All other taxonomic characters matched keys for W. carteri (McMichael & Hiscock 1958; Walker 2004). Mussels in Dog Hill and Lowlands Forest were the largest, dominated by individuals in the 70-80 mm shell length range (Figure 74) followed by Serpentine-Birrega Confluence, Lowlands Gauging Station and Coffee Rocks, dominated by individuals in the 60-70 mm shell length range and the smallest mussels were found at Horse Drink, the majority of which fell within the 60-65 mm length range. Average shell lengths of mussels among and between sites were statistically different (F = 14.562; df = 5, 780; P < 0.001).

A preliminary growth trial where a representative sample of various size classes within Horse Drink and Dog Hill were marked and recaptured annually from March 2010 to March 2011, growth rates of mussels in Dog Hill were six times greater than for mussels in the Horse Drink site for individuals within the 30-60 mm shell length range (t = 4.934, df = 48, P < 0.001). Also, mussels within Birrega Drain were significantly more obese (using MHI as an indicator) than mussels within the Serpentine River (F = 6.883; df = 5, 589; P < 0.001), suggesting greater visceral mass, which is probably due to increased temperature and eutrophication within the drain as suggested from other international studies (Agrell 1948; Arter 1989; Franke 1993; Müller 1995).

From the location of smaller individuals (<30 mm), the population of W. carteri within the Serpentine River of the Lowlands Bush Forever site appears to have had some recent recruitment, but the lack of a greater number of individuals in the smaller size classes suggests the population is aging and recruitment has become less frequent in recent history. A validated age-at-length growth study of W. carteri within several populations of its distributional range will be published in 2012 and will help explain whether this is the case.

107 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

35 30 Dog Hill Degraded sites 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

35 30 Serpentine - Birrega Confluence 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

35 30 Lowlands Gauging Station 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Natural sites 35 30 25 Coffee Rocks 20 15 Number of mussels 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

35 30 Horse Drink 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

35 30 25 Lowlands Forest 20 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Shell length (mm) Figure 74. Length-frequency histograms of Westralunio carteri in the Serpentine River and Birrega Drain. 108 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Glochidia-host fish relationships

During this study, six fish species (n = 1275 individual fishes) were examined for glochidia of W. carteri and were found attached primarily to the fins, but occasionally to the body, eye, mouth and very rarely to the gills. Glochidia obtained from the gills of gravid adult female W. carteri were similar in morphology to those reported by Klunzinger et al. 2010b, 2011), suggesting they were W. carteri offspring. Glochidia prevalence and intensity peaked in November, gradually reducing in subsequent months. By January, virtually no glochidia remained attached to any fishes, suggesting a seasonal pattern of glochidia attachment. Recent work by the authors has shown that glochidia of W. carteri remain attached to host fishes for 21-27 days under laboratory conditions and glochidia release occurs from October and December within freshwater tributaries of the Swan-Canning estuary based on data collected in 2009-2010 (Klunzinger et al. unpublished data). During this study however, we were surprised to find glochidia being released from W. carteri during late August. Studies of other species of freshwater mussels have suggested that reproduction and recruitment is boosted in wetter years (e.g. Hastie et al. 2003).

Overall, peak glochidia prevalence ranged from 5.3 to 62.9% (Figure 75) and intensities ranged from 1 to 19 glochidia per infested fish (Table 9). For each fish species ≥10(n fish) among the sites sampled, peak glochidia prevalences were significantly different (χ2 = 56.977, df = 7, P < 0.001), as were intensities (H = 34.11, df = 12, P < 0.001). Peak glochidia prevalence of fishes captured within ‘natural’ sites was significantly greater than fishes captured from ‘degraded’ sites (63.4% vs. 23.9%; χ2 = 43.336, df = 1, P < 0.001). Considering each species separately among sampling sites, glochidia prevalence and intensity was positively associated with adult mussel density (R2 = 0.884 – 1.00) (see Figures 76-77), such that greater adult mussel densities within sites led to greater glochidia prevalences and intensities for each species. Prevalence was greater in native fishes than in ferals (70.6% vs. 29.45%, respectively; χ2 = 18.823, df = 1, P < 0.001). A recent study testing the suitability of various fishes as hosts suggests that feral fishes may be less suitable from their inability to produce juvenile W. carteri (Klunzinger et al., in review). Like other freshwater mussels found throughout Australia, this freshwater mussel appears to be a host generalist utilising a number of host fishes also endemic to the south-west, probably to maximise its chances for recruitment (Walker 1981; Humphrey 1984; Widarto 1996; Klunzinger et al., in review). Survival and growth rates of W. carteri glochidia and juvenile mussels on fishes and in sediments is likely to vary with a number of factors including ammonia concentration, sediment type, the presence of predators or contaminants such as salt, chlorine and other harmful chemicals, based on studies of other freshwater mussels elsewhere (Walker 1981; Strayer 2008).

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Fishes that undergo long distance spawning migrations, such as Western Minnows, probably help to maintain connectivity of freshwater mussel colonies by distributing their glochidia to new areas on a large scale and perhaps prevent inbreeding by distributing the gene pool from various colonies (Pen 1999; Strayer 2008). Some fishes however, may be responsible for maintaining recruitment of freshwater mussels in localised patches (Strayer 2008; Jones & Byrne 2010). More information on the movement patterns of host fishes and the genetic diversity of freshwater mussels within catchments as well as the longevity of W. carteri is necessary to determine long-term population viability of the species within the Serpentine River and other systems across the south-west.

Goldfish (0.1 - 26.0)

Eastern Gambusia (0 - 98.2)

Western Minnow (0 - 100)

Western Pygmy Perch (25.7 - 89.3)

Swan River Goby (14.6-100 )

0 10 20 30 40 50 60 70 80 90 100

Glochidia prevalence (%) Figure 75. Overall glochidia prevalence in fishes examined from the Serpentine River and Birrega Drain with 95% Confidence Intervals given in brackets. Red bars represent feral fishes and green bars are native fishes.

Table 9. Overall peak glochidia intensity for each fish species captured within the Serpentine River and Birrega Drain. Sample means were significantly different at the P<0.05 level. †Feral fish species Fish Species No. examined Intensity range Average intensity (No./infested fish ±S.E.) Eastern Gambusia† 110 1-9 1.46 ± 0.29 Western Minnow 80 1-19 2.39 ± 1.09 Swan River Goby 47 1-16 2.84 ± 0.94 Western Pygmy Perch 30 1-17 3.58 ± 1.76 Goldfish† 19 6 6 Nightfish 21 1-16 6.17 ± 3.84

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100

90

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60

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30

20 Peak glochidia prevalence (%) Peakglochidia prevalence 10

0 2 4 6 8

Adult mussel density (No./m2)

2 Swan River Goby: y=30.838+7.512x, R =0.988, P<0.01 2 Eastern Gambusia: y=7.995+6.111x, R =0.954, P<0.01 2 Western Pygmy Perch: y=21.364+9.091x: R =1.00 2 Western Minnow: y=17.049+8.143x: R =0.993, P<0.01

Figure 76. Regression plots of mean adult freshwater mussel (Westralunio carteri) density vs. peak glochidia prevalence in four individual fish species captured from sampling sites within the Serpentine River or Birrega Drain. Each data point represents individual fish species within individual sampling sites.

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2 Swan River Goby: y=1.22+0.379x, R =0.915, P<0.01 2 Eastern Gambusia: y=0.943+0.121x, R =0.982, P<0.01 2 Western Pygmy Perch: y=-21.793+6.382x, R =1.00 2 Western Minnow: y=0.564+0.43x, R =0.884, P=0.22

Figure 77. Regression plots of mean adult freshwater mussel (Westralunio carteri) density vs. peak glochidia intensity in four individual fish species captured from sampling sites within the Serpentine River or Birrega Drain. Each data point represents individual fish species within individual sampling sites.

112 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Conservation significance and management recommendations

From the regular monitoring of the six sampling sites, it is clear that native freshwater fishes are utilizing the Lowlands Bush Forever conservation block as an important spawning ground, particularly with the discovery of downstream migrating juvenile Pouched Lamprey, suggesting that this Priority 1 fauna, a species which requires specific habitats for development, is using the area to breed. The Vulnerable, Priority 4 Carter’s Freshwater Mussel was present in the Serpentine River and Birrega Drain. Generally speaking, the complex woody, well vegetated habitats which received little to no human impacts in recent years, within the Lowlands Bush Forever sites were more conducive to freshwater mussel recruitment and native freshwater fish and crayfish populations. Conversely, the degraded habitats within and downstream from the cattle crossing were more heavily laden with feral fishes and crayfishes. In some cases, the sites were virtually devoid of freshwater mussels. Although we have not presented very much information about the heavily impacted cattle crossing upstream from Lowlands Gauging Station, the area was surveyed for freshwater mussels by students from the Central Institute of Technology, but none were found (see Appendix). The construction of a bridge to reduce the impacts from cattle crossing the river will help to reduce erosion and sedimentation as well as nutrient inputs and riparian re-vegetation, restricting livestock from using the river banks and improving the river with the introduction of woody debris to encourage native freshwater fish habitation and freshwater mussel re-colonisation and follow-up monitoring is recommended. The fencing throughout the property is in good condition and should continue to be maintained to protect the integrity of the riparian zone. The controlled access point for cattle below the Lowlands Gauging Station is proving to be beneficial in terms of riparian vegetation re-generation and possibly a reduction in sedimentation, but the buildup of fine detritus within the pool below the access point is concerning. The low winter rainfall in 2010 and lack of flow in the summer of 2011 undoubtedly played a role in the buildup of fine sediments, which should have been flushed with adequate winter rains and environmental water provisions. The rarity of Western Pygmy Perch within the study area may be due, in part, to the large numbers of Eastern Gambusia which were probably responsible for the extreme fin nipping of juvenile Western Pygmy Perches observed during the study. Although few Smooth Marron were captured in the study, the deep pools near Coffee Rocks and Rapids Road housed sizeable males and females. The discovery of the parasitic crustacean (Lernaea cyprinacea) or ‘Anchor Worm’ on native freshwater fishes at Rapids Road and pools within the Birrega Drain is particularly concerning and probably has been spread by Goldfish. No Lernaea were found on any of the Goldfishes captured, suggesting that the native fishes are now a preferred host. A dedicated study to determine whether this parasite is causing native species declines is necessary in the

113 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH near future. We also found that feral fish eradication was most successful through electro- fishing and seine netting during late spring and summer, when we successfully eradicated a number of Goldfish within the Birrega Drain and just below the Lowlands Gauging Station. Indeed, the gauging station weir may be acting as a barrier to prevent upstream migration of Goldfish from the Birrega Drain into the upstream regions of the Serpentine River, although weirs have also been shown to be detrimental to native fishes by blocking upstream spawning migrations and disconnecting freshwater mussel patches by preventing the movement of glochidia on host fishes, which could have implications for maintaining genetic integrity of the rare Carter’s Freshwater Mussel. Also worth mentioning, besides Carter’s Freshwater Mussel and the Pouched Lamprey, there were several other significant flora and fauna observed during the study, which included the Priority 4 listed Dusky Moorhen (Gallinula tenebrosa), the Southwestern Silkpod (Parsonsia diaphenophleba) and, as confirmed by Karen Bettink’s concurrent study, the charismatic Water Rat (Hydromys chrysogaster).

From this study, monitoring freshwater mussels, fishes and crayfishes has proven useful as an indication of adaptive management success and using native species, particularly Carter’s Freshwater Mussel and its native host fishes as bioindicators of freshwater river health should be used in future ecological work to monitor and manage natural resource integrity.

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References

Agrell, I. (1948). The shell morphology of some Swedish unionoids as affected by ecological conditions. Arkiv for Zoologi 41: 1-30. Allen, G.R, Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia. Western Australian Museum, Perth. Alonso, A.D. (2009). Marron growing: a Western Australian rural niche market? Asia Pacific Journal of Marketing and Logistics 21: 433-446. Arter, H.E. (1989). Effect of eutrophication on species composition and growth of freshwater mussels in Lake Hallwil (Aargau, Switzerland). Aquatic Science 51: 87-89. Aquatic Research Laboratories (ARL). (1988). Lower Canning River stream fauna study results and recommendations. Report 11 June 1988, University of Western Australia. Austin, C.M. & Knott, B. (1996). Systematics of the freshwater crayfish genus Cherax Erichson (Decapoda: Parastacidae) in south-western Australia: Electrophoretic, Morphological and Habitat Variation. Australian Journal of Zoology 44: 223–58. Austin, C.M. & Ryan, S.G. (2002). Allozyme evidence for a new species of freshwater crayfish of the genus Cherax Erichson (Decapoda: Parastacidae) from the south-west of Western Australia. Invertebrate Systematics 16: 357–67. Australian and New Zealand Environment and Conservation Council (ANZECC) & Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ). (2000). Chapter 3: Aquatic Ecosystems. In: Australian and New Zealand Guidelines for Fresh and Marine Water Quality. (pp. 3.1-1 – 3.3-16) Bamford, M., Morgan, D. & Gill, H. (1998). The freshwater fish fauna of Bennett Brook. Murdoch University Fish Group Report to the Bennett Brook Catchment Group. Bauer, G. & Wächtler, K. (2001). Ecology and Evolution of the Freshwater Mussels Unionoida. New York, Springer- Verlag. Beatty, S.J. (2005). Translocations of freshwater crayfish: contributions from life histories, trophic relations and diseases of three species in Western Australia. PhD Thesis, Murdoch University, Perth, Western Australia. Beatty, S.J. (2006). The diet and trophic positions of translocated, sympatric populations of Cherax destructor and Cherax cainii in the Hutt River, Western Australia: evidence of resource overlap. Marine and Freshwater Research 57(8): 825-835. Beatty, S. & Morgan, D. (2006). Management of aquatic fauna during refurbishment of Phillips Creek Reservoir. Murdoch University, Centre for Fish & Fisheries Research, Murdoch University Report to the Water Corporation of Western Australia. Beatty, S. & Morgan, D. (2008). Fishway assessment for the Pinjarra Weir. Centre for Fish & Fisheries Research, Murdoch University Report to Peel-Harvey Catchment Council. Beatty, S.J. & Morgan, D.L. (2010) Teleosts, agnathans and macroinvertebrates as bioindicators of ecological health in a south-western Australian river. Journal of the Royal Society of Western Australia 93: 65-79. Beatty, S., Morgan, D. & Gill, H. (2003a). Fish resource survey of Churchman Brook Reservoir. Report to the Water Corporation of Western Australia. Beatty, S.J., Morgan, D.L. & Gill, H.S. (2003b). Reproductive biology of the large freshwater crayfish Cherax cainii in south-western Australia. Marine & Freshwater Research 54: 597-608. Beatty, S., Morgan, D. & Gill, H. (2003c). Fish resource survey of Phillips Creek Reservoir. Centre for Fish & Fisheries Research, Murdoch University Report to the Water Corporation of Western Australia. Beatty, S.J., Morgan, D.L. & Gill, H.S. (2005a). Role of life history strategy in the colonisation of Western Australian aquatic systems by the introduced crayfish Cherax destructor Clark, 1936. Hydrobiologia 549: 219-237.

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Beatty, S.J., Morgan, D.L. & Gill, H.S. (2005b). Life history and reproductive biology of the gilgie Cherax quinquecarinatus, a freshwater crayfish endemic to south-western Australia. Journal of Crustacean Biology 25(2): 251-262. Beatty, S.J., Morgan, D.L. & Gill, H.S. (2005c). Biology of a translocated population of the large freshwater crayfish, Cherax cainii Austin and Ryan, 2002 in a Western Australian river. Crustaceana 77 (11): 1329-1351. Beatty, S., Morgan, D., McAleer F., Koenders A. & Horwitz P. (2006). Fish and freshwater crayfish communities of the Blackwood River: migrations, ecology and the influence of surface and groundwater. Centre for Fish & Fisheries Research, Murdoch University Report to South-west Catchments Council and Department of Water, Western Australia. Beatty, S., Morgan, D., Sarre, G., Cottingham, A. & Buckland, A. (2010a). Assessment of the distribution and population viability of the Pearl Cichlid in the Swan River catchment, Western Australia. Murdoch University, Centre for Fish & Fisheries Research report to the Swan River Trust. Beatty, S.J., Morgan, D.L., McAleer, F.J. & Ramsay, A.R. (2010b). Groundwater contribution to baseflow maintains habitat connectivity for Tandanus bostocki (Teleostei: Plotosidae) in a south-western Australian river. Ecology of Freshwater Fish 19: 595-608. Beatty, S.J., Morgan, D.L., Rashnavadi, M. & Lymbery, A.J. (2011). Salinity tolerances of endemic freshwater fishes of south-western Australia: implications for conservation in a biodiversity hotspot. Marine & Freshwater Research 62: 91-100. Bettink, K. (2011). Rakali – no ordinary rat. Watsnu 17: 1. Crandall, K.A., Fetzner, J.W., Lawler, S.H., Kinnersley, M. & Austin, C.M. (1999). Phylogenetic relationships among the Australian and New Zealand genera of freshwater crayfishes (Decapoda: Parastacidae). Australian Journal of Zoology 47: 199–214. Davis, J.A., Barmuta, L.A. & Balla, S.A. (1988). Serpentine River & Gooralong Brook aquatic fauna study. Murdoch University School of Biological and Environmental Sciences, report to the Water Authority of Western Australia. Davis, J. & Christidis, F. (1999). A guide to wetland invertebrates of southwestern Australia. Western Australian Museum, Perth. De Graaf, M. & Coutts, T. (2010). Invasive potential of a South‐American fish species, Geophagus brasiliensis, in the Swan River, Western Australia: based tolerance to instantaneous and gradual changes in salinity. Journal of the Royal Society of Western Australia 93: 147‐151. De Graaf, M., Beatty, S. & Molony, B.M. (authors). Baxter, D. & Larsen, R. (eds.). (2010). Evaluation of the recreational marron fishery against environmental change and human interaction. Final report to Fisheries Research and Development Coporation on Project No. 2003/027. Fisheries Research Report N. 211. Department of Fisheries, Western Australia. 188pp. Department of Environment and Conservation, Government of Western Australia (DEC). (2011). Current list of threatened fauna rankings. Available at http://www.dec.wa.gov.au Franke, G. (1993). Zur Populationökologie und Geschlechtsbiologie der Teichmuschel Anodonta anatine L. und Anodonta cygnea L. MSc Thesis, Universität Bayreuth. Gill, H.S., Hambleton, S.J. & Morgan, D.L. (1999). Is Gambusia holbrooki a major threat to the native freshwater fishes of south-western Australia? In: Proceedings 5th Indo-Pacific Fish Conference (Noumea, 3-8 November1997). Seret, B. and Sire, J.-Y., eds. pp. 79-87. Paris: Societe Francaise d’Ichtyologie and Institut de Recherche pour le Development. Hastie, L.C., Cosgrove, P.J., Ellis, N. & Gaywood, M.J. (2003). The threat of climate change to freshwater pearl mussel populations. Ambio 32: 40-46. Hewitt, M.A. (1992). The biology of the south-western Australian catfish Tandanus bostocki Whitley (Plotosidae). Honours Thesis, Murdoch University, Perth, Western Australia.

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Horwitz, P. (1990). The translocation of freshwater crayfish in Australia: Potential impact, the need for control and global relevance. Biological Conservation 54: 291-305. Horwitz, P. (1995). The conservation status of Australian freshwater crayfish: Review and update. Louisiana State University, Baton Rouge, LA (USA). pp. 70-80. Horwitz, P. & Adams, M. (2000). The systematics, biogeography and conservation status of species in the freshwater crayfish genus Engaewa Riek (Decapoda: Parastacidae) from south-western Australia. Invertebrate Taxonomy 14: 655–80. Humphrey, C.L. (1984). Biology and ecology of the freshwater mussel Velesunio angasi (Bivalvia: Hyriidae) in the Magela Creek, Alligator Rivers region, Northern Territory. PhD Thesis, University of New England. Hussey, B.M.J. & Keighery, G.J. (2007). Western weeds: A guide to the weeds of Western Australia. Weeds Society of Western Australia, Victoria Park. International Union for the Conservation of Nature (IUCN). (2011). Mollusc Specialist Group 1996. Westralunio carteri. In: IUCN 2011. IUCN Red List of Threatened Species. Available at http://www.iucnredlist.org. Jones, H.A. & Byrne, M. (2010). The impact of catastrophic channel change on freshwater mussels in the Hunter River system, Australia: a conservation assessment. Aquatic Conservation: Marine and Freshwater Ecosystems 20: 18-30. Keleher, J. (2010). The effectiveness of current fishway designs in Australia’s south west to accommodate endemic freshwater fish species. BSc (Hons) Thesis, Murdoch University, Perth. Kendrick, G.W. (1976). The Avon: faunal and other notes on a dying river in south-western Australia. The Western Australian Naturalist 13(5): 97-114. Klunzinger, M. (2011). Freshwater shrimp (Palaemonetes australis) may be involved in Glochidia release from the freshwater mussel Westralunio carteri. The Western Australian Naturalist 28: 61-65. Klunzinger, M., Beatty, S. & Lymbery, A. (2010). Acute salinity tolerance of the freshwater mussel Westralunio carteri Iredale, 1934 of south-west Western Australia. Tropical Natural History Suppl. 3: 112. Klunzinger, M.W., Beatty, S.J., Morgan, D.L., Lymbery, R., Thomson, G.J. & Lymbery, A.J. (2011a). Discovery of a host fish species for glochidia of Westralunio carteri Iredale, 1934 (Bivalvia: Unionoida: Hyriidae). Journal of the Royal Society of Western Australia 94: 19-23. Klunzinger, M.W., Beatty, S.J. & Lymbery, A.J. (2011b). Freshwater mussel response to drying in the Lower Helena Pipehead Dam & mussel translocation strategy for conservation management. Murdoch University, Centre for Fish & Fisheries Research Report to the Swan River Trust. Kolmakov, V.I. & Gladyshev, M.I. (2003). Growth and potential photosynthesis of cyanobacteria are stimulated by viable gut passage in crucian carp. Aquatic Ecology 37: 237-242. Lavery, P., Bootle, S. & Vanderklift, M. (1999). Ecological effects of macroalgal harvesting on beaches in the Peel- Harvey Estuary. Estuarine, Coastal and Shelf Science 49: 295-209. Lenanton, R.C.J., Potter, I.C., Loneragan, N.R. & Chrystal, P.J. (1984). Age structure and changes in abundance of three important teleosts in a eutrophic estuary. Journal of Zoology 203: 311-327. Loneragan, N.R., Potter, I.C., Lenanton, R.C.J. & Caputi, N. (1986). Spatial and seasonal differences in the fish fauna in the shallows of a large Australian estuary. Marine Biology 92: 575-586. Lymbery, A., Lymbery, R., Morgan, D. & Beatty, S. (2008). Freshwater mussels (Westralunio carteri) in the catchments of Geographe Bay, south-western Australia. Murdoch University, Fish Health Unit, Report to the Water Corporation, Western Australia. Lynas, J., Storey, A.W. & Knott, B. (2007). Aggressive interactions between three species of freshwater crayfish of the genus Cherax (Decapoda: Parastacidae). Marine and Freshwater Behaviour and Physiology 40: 105-116. Maddern, M. (2003). The distribution, biology and ecological impacts of three introduced freshwater teleosts in Western Australia. Honours Thesis, Murdoch University, Perth, Western Australia. Marchant, N.G. (1987). Flora of the Perth Region. Parts 1 and 2. Western Australian Herbarium, South Perth.

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Marina, H., Beatty, S.J., Morgan, D.L., Doupé, R.G. & Lymbery, A.L. (2008). An introduced parasite, Lernaea cyprinacea, found on native freshwater fish in the south west of Western Australia. Journal of the Royal Society of Western Australia 91: 149-153. Mayer, X., Ruprecht, J., & Bari, M. (2005). Stream salinity status and trends in south-west Western Australia. Department of Environment, East Perth, WA: Salinity and Land Use Impact Series, Report No. SLUI 38. McComb, A.J. & Humphries, R. (1992). Loss of nutrients from catchments and their ecological impacts in the Peel- Harvey esutuarine system, Western Australia. Estuaries and Coasts 15: 529-537. McMichael, D.F. & Hiscock, I.D. (1958). A monograph of the freshwater mussels (Mollusca: Pelecypoda) of the Australian Region. Australian Journal of Marine and Freshwater Research 9: 372-507. McNally, J. (1960). The biology of the water rat Hydromys chrysogaster Geoffroy (Muridae: Hydromynae) in Victoria. Australian Journal of Zoology 8: 170-180. Molony, B., Beatty, S., Bird, S. & Nguyen, V. (2005). Mitigation of the negative impacts on biodiversity and fisheries values of the refurbishment of Waroona Dam, south-western Australia. Fisheries Research Contract Report No. 12, Department of Fisheries, Western Australia and Murdoch University, Centre for Fish & Fisheries Research, Perth. Morgan, D. & Beatty, S. (2003). Fish fauna of the Hotham River (including the impact of the Lion’s Weir on fish migration). Report to the Water and Rivers Commission of Western Australia & Boddington Rivers Action Group. Morgan, D.L. & Beatty, S.J. (2007). Feral Goldfish (Carassius auratus) in Western Australia: a case study from the Vasse River. Journal of the Royal Society of Western Australia 90(3): 151-156. Morgan, D.L., Gill, H.S. & Potter, I.C. (1998). Distribution, identification and biology of freshwater fishes in south- western Australia. Records of the Western Australian Museum Supplement No. 56: 1-97. Morgan, D., Gill, H. & Cole, N. (2000). The fish fauna of the Moore River catchment. Murdoch University report to the Water & Rivers Commission. Morgan, D.L., Thorburn, D.C. & Gill, H.S. (2003). Salinization of south-western Western Australian rivers and the implications for the inland fish fauna – the Blackwood River, a case study. Pacific Conservation Biology 9: 161-171. Morgan, D.L, Gill, H.S., Maddern, M.G. & Beatty, S.J. (2004). Distribution and impacts of introduced freshwater fishes in Western Australia. New Zealand Journal of Marine and Freshwater Research 38: 511-523. Morgan, D.L., Beatty, S.J. & McAleer, F.J. (2007). Canning River – freshwater fishes and barriers to migrations. Centre for Fish & Fisheries Research, Murdoch University Report to Department of Water and South East Regional Centre for Urban Landcare. Morgan, D., Beatty, S. & Kurata, K. (2008). Feral Goldfish (Carassius auratus) in the Warren River catchment. Centre for Fish & Fisheries Research, Murdoch University Report to Southern Forests Landcare. Morgan, D.L., Beatty, S.J. & Sarre, G.A. (2009). Ascending the Avon: fishes of the Northam Pool, and the Swan-Avon catchment. Centre for Fish & Fisheries Research, Murdoch University, Western Australia. Morgan, D.L.., Beatty, S.J., Klunzinger, M.W., Allen, M.G. & Burnham, Q.F. (2011). A field guide to freshwater fishes, crayfishes & mussels of south-western Australia. Published by SERCUL and the Freshwater Fish Group & Fish Health Unit, Centre for Fish & Fisheries Research, Murdoch University, Perth. Morrison, P.F. (1988). Reproductive biology of two species of plotosid catfish, Tandanus bostocki and Cnidoglanis macrocephalus, from south-western Australia. PhD Thesis, University of Western Australia. Morrissy, N.M. (1978). The past and present distribution of marron, Cherax tenuimanus, in Western Australia. Fisheries Research Bulletin of Western Australia 22: 1–38. Morrissy, N.M., Caputi, N. & House, R.R. (1984). Tolerance of marron (Cherax tenuimanus) to hypoxia in relation to aquaculture. Aquaculture 41: 61-74.

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Mutvei, H. & Westermark, T. (2001). How environmental information can be obtained from naiad shells. In: Ecology and Evolution of the Freshwater Mussels Unionoida. G. Bauer and K. Wächtler (eds). Berlin, Springer: 367-382. Müller, D. (1995). Populationökologie der Großen Teichmuschel, Anodonta cygnea (L.), in den Seen des Salzburger Alpenvorlandes. MSc Thesis, Univeristät Salzburg. Pen, L.J. (1999). Managing our rivers. Water and Rivers Commission, East Perth. Ponder, W.F. & Walker, K.F. (2003). From mound springs to mighty rivers: the conservation status of freshwater molluscs in Australia. Aquatic Ecosystem Health and Management 6(1): 19-28. Potter, I.C. & Hyndes, G.A. (1994). Composition of the fish fauna of a permanently open estuary on the southern coast of Australia, and comparions with a nearby seasonally closed estuary. Marine Biology 121: 199-209. Potter, I.C., Loneragan, N.R., Lenanton, R.C.J., Chrystal, P.J. & Grant, C.J. (1983). Abundance, distribution and age structure of fish populations in a Western Australian estuary. Journal of Zoology 200: 21-50. Rozsa, L., Reiczigel, J. & Majoros, G. (2000). Quantifying parasites in samples of hosts. Journal of Parasitology 86: 228-232. Storey, A.W. & Edward, D.H.D. (1989). The freshwater mussel, Westralunio carteri Iredale, as a Biological monitor of Organochlorine Pesticides. Australian Journal of Marin and Freshwater Research 40: 587-593. Strayer, D.L. (2008). Freshwater mussel ecology: a multifactor approach to distribution and abundance. Berkley, University of California Press. Strayer, D.L. & Smith, D.R. (2003). A Guide to Sampling Freshwater Mussel Populations. Bethesda, Maryland, USA, American Fisheries Society Monograph 8. Suppiah, R., Hennessy, K.J., Whetton, P.H., McInnes, K., Macadam, I., Bathols, J., Ricketts, J. & Page, C.M. (2007). Australian climate change projections derived from simulations performed for the IPCC 4th Assessment Report. Australian Meteorological Magazine 131: 131-52. Tay, M.Y., Lymbery, A.J., Beatty, S.J. & Morgan, D.L. (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. Threatened Species Scientific Committee (TSSC). (2004). Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (the Committee) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act): Cherax tenuimanus (Hairy Marron). Vaughn, C.C. & Hakenkamp, C.C. (2001). The functional role of burrowing bivalves in freshwater ecosystems. Freshwater Biology 46(11): 1431-1446. Veale, L., Coulson, P., Hoeksema, S., Potter, I. & Hall, N. (2010). Current status of the fish fauna of the Peel-Harvey and Leschenault estuaries. Western Australian Marine Science Institution (WAMSI) Node 4 Synthesis and Integration Workshop, December 2010, Western Australian Marine Research Laboratories, Hillarys, Western Australia. WAMSI 4.2.1 (a) Walker, K.F. (1981). Ecology of freshwater mussels in the River Murray. Australian Water Resources Council, Canberra. Walker, K.F. (2004). A guide to the provisional identification of the freshwater mussels (Unionoida) of Australasia. Albury, Murray Darling Freshwater Research Centre. Walker, K.F., Byrne, M., Hickey, C.W. & Roper, D.S. (2001). Freshwater mussels (Hyriidae) of Australia. In: Ecology and Evolution of the Freshwater Mussels Unionoida. G. Bauer and K. Wächtler eds. Berlin, Springer: 5-31. Western Australian Planning Commission (WAPC). (2000). Bush Forever Volume 1, Western Australian Planning Commission (WAPC), Government of Western Australia, Perth.

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Watts, R.J., Storey, A.W., Hebbert, D.R. & Edward, D.H.D. (1995). Genetic and morphological differences between populations of the western minnow, Galaxias occidentalis, from two river systems in south-western Australia. Marine and Freshwater Research 46: 769-777. Wheeler, J.R., Marchant, N.G., Lewington, M. & Graham, L. (2002). Flora of the south west: Bunbury – Augusta – Denmark. Volumes 1 and 2. Australian Biological Resources Study and Western Australian Herbarium in Association with University of Western Australia Press, Canberra. Widarto, T.H. (1996). Some aspects of reproductive biology of freshwater mussels living in a tropical area. Hayati 3: 21-25.

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APPENDIX I Extension of this study

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This study created mutually beneficial opportunities for community natural resource managers as well as training opportunities for postgraduate researchers and vocational training of Environmental Science students in the (formerly TAFE) vocational and university level tertiary education sectors. A summary of projects are included below:

Michael Klunzinger, PhD candidate

Ecology and Life History of the Freshwater mussel: Westralunio carteri Iredale, 1934

Program of Study

The PhD thesis is focused on the freshwater mussel Westralunio carteri, an endemic freshwater mussel of south-western Australia. Until this study began in 2009, very little information existed on the distribution, abundance and life cycle of the species existed, apart from a few sporadic declarations of species loss from salinisation, brief mentions of its existence in macroinvertebrate studies and occasional use as a bioindicators of contaminants. The objectives of the thesis were to:

(1) Establish distributional information of the species (2) Quantify environmental tolerances and habitat occupancy (3) Examine reproductive biology and growth rates (4) Identify host fish for the larval stage (‘glochidia’)

Supervisors: Alan Lymbery, David Morgan, Stephen Beatty

Commencement date: 22 June 2009

Expected completion date: 22 June 2012

Relevant publications submitted during this NRM project:

1) Klunzinger M W, Beatty S J, Morgan D L & Lymbery A J (in review) ‘What makes a host fish suitable? A study of glochidiosis in a biodiversity hot-spot.’ Journal of Zoology 2) Morgan D L, Beatty S J, Klunzinger M W, Allen M G & Burnham Q E (2011) ‘A Field Guide to Freshwater Fishes, Crayfishes & Mussels of South-Western Australia.’ Published by SERCUL & Freshwater Fish Group & Fish Health Unit (Murdoch University), Murdoch, Western Australia. 3) Klunzinger M, Beatty S & Lymbery A (2010) ‘Acute salinity tolerance of the freshwater mussel Westralunio carteri (Iredale 1934) of south-west Western Australia.’ Tropical Natural History Suppl. 3: 112. 4) Klunzinger M, Beatty S, Thomson G & Lymbery A (2010) ‘Glochidia tooth morphology of the freshwater mussel Westralunio carteri (Iredale 1934) of south-west Western Australia.’ Tropical Natural History Suppl. 3: 246.

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Stefania Basile, BSc (Hons)

Impacts of the introduced parasite Lernaea cyprinacea (Linnaeus, 1758) (Lernaeidae) on the native and exotic fishes of south-western Australia

ABSTRACT Exotic species present a major threat to native freshwater fishes in south-western Australia through predation, competition for habitat and resources and in some cases the alteration of habitat and water quality. They may also introduce diseases, although much less is known about the threat posed to native freshwater fishes by exotic diseases. Until very recently, records of the introduced parasitic crustacean Lernaea cyprinacea (Linnaeus, 1758) (Lernaeidae) in Australia were limited and restricted to the eastern states (Victoria and New South Wales). The first published records of L. cyprinacea found on freshwater fishes in Western Australia was in 2008. The current study examines the distribution of this parasite in the south-west of Western Australia, compares the prevalence and intensity of parasite infestation in different host species, as well as the potential causes of differences in prevalence and intensity and examined these findings in the light of management practices for exotic fish species. Lernaea cyprinacea was found on fishes in three river systems of the South West Coast Drainage Division (SWCDD): the Canning River and its tributary the Southern River, in which the parasite had been previously recorded, and the Serpentine River (Rapids Rd & Birrega Drain) and Murray River, which represent new distribution records for L. cyprinacea. As well as an expansion in the geographical range of L. cyprinacea that was observed in the SWCDD during this study, two new native fish species were found to be hosts for L. cyprinacea.

The results of the current study have implications regarding the control or eradication of exotic fish species in Western Australia in terms of potential consequences on the host-parasite association between native fish species and L. cyprinacea. Although requiring further research, the removal of C. auratus from the wild could potentially increase L. cyprinacea disease risk in native fish species by promoting L. cyprinacea transmission to the more susceptible native fish species. However, there are ecological benefits in the control of feral fishes.

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‘Anchor worm’ (Lernaea cyprinacea) infections on feral Goldfish (Carassius auratus). Photos: Stefania Basile

‘Anchor worm’ (Lernaea cyprinacea) infections on native Freshwater Cobbler (Tandanus bostocki). Photos: Simon Visser

‘Anchor worm’ (Lernaea cyprinacea) infections on native Western Pygmy Perch (Nannoperca vittata) – left and native Nightfish (Bostockia porosa) - right. Photos: Stefania Basile

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APPENDIX II

Characteristic riparian vegetation observed during this study

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Overstorey plant species

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Middlestorey plant species

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Middlestorey plant species (cont’d)

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Middlestorey plant species (cont’d)

Parsonsia diaphanophleba Photo: Mark Allen

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(INTRODUCED MIDDLESTOREY SPECIES)

Ficus carica Photos: http://www.designrulz.com

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Understorey plant species

Baumea articulata Photos: C. Miller

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Understorey plant species(cont’d)

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Understorey plant species(cont’d) (INTRODUCED UNDERSTOREY SPECIES)

Juncus usitatus Photo: http://www.plantsandlandscapes.com

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Understorey plant species(cont’d)

(INTRODUCED UNDERSTOREY SPECIES)

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Understorey plant species(cont’d)

(INTRODUCED UNDERSTOREY SPECIES)

Poaceae sp. Photo: Mark Allen

Watsonia sp. Photo: Mark Allen

137 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

APPENDIX III

The Serpentine River – Then and Now

138 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

‘Horse Drink’, Lowlands, Serpentine river ca. 1918, horses pulling logs out of river to make way for the steam pump on the Richardson family property. Photo was originally sent to the boys serving in World War I.

‘Horse Drink’, Lowlands, Serpentine River, 31 August 2011. Notice regeneration of riparian vegetation.

139 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine River, near Coffee Rocks (December Serpentine River, near Coffee Rocks 1940). Bill Richardson and cousin David in (23 February 2011). homemade canoes.

Serpentine River in flood over livestock paddocks at Lowlands/Riverlea (1955).

140 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Photo taken from the roof of Bill Richardson’s homestead overlooking the Serpentine River, Riverlea and Lowlands; Midge Richardson’s homestead can be seen in the distance (1939).

141 ECOLOGY OF AQUATIC FAUNA IN THE SERPENTINE RIVER IN RESPONSE TO LAND USE PRACTICES & RECOMMENDATIONS FOR IMPROVING FRESHWATER ECOSYSTEM HEALTH

Serpentine Falls, before the dam was built Serpentine Falls (2009). (pre World War I). .

End of Coffee Rocks facing upstream with child’s Lucy and Midge Richardson riding their ponies across play hut built on the rocks near Bill Richardson’s the Serpentine River after winter rains near ‘Cottage homestead (ca. 1936). Field Gully’ in the Serpentine River, upstream from . the area where Lowlands Gauging Station now stands (1947). .

The old bridge crossing the Serpentine River near Midge Richardson’s homestead to the right; an old mail coach track which linked the area to Perth, Serpentine River in flood over cattle paddocks Mandurah and Bunbury can be seen in the (ca. 1940’s). foreground (pre-1942). 142