An Assessment of the Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

AN ASSESSMENT OF THE AQUATIC FAUNA IN GARDINERS, SCOTCHMANS, BACK AND DAMPER CREEKS

for Melbourne Water Waterways and Drainage

Wayne Koster

Freshwater Ecology Section Arthur Rylah Institute for Environmental Research

May 2002 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Title AN ASSESSMENT OF THE AQUATIC FAUNA IN GARDINERS, SCOTCHMANS, BACK AND DAMPER CREEKS

Produced by Wayne Koster

Arthur Rylah Institute for Environmental Research Department of Natural Resources and Environment PO Box 137 Heidelberg Victoria 3084

Telephone: (03) 9450 8600 Facsimile: (03) 9450 8730

Produced for Melbourne Water Corporation Waterways and Drainage

Contact Rhys Coleman Waterways and Drainage Melbourne Water Corporation GPO Box 4342 Melbourne Victoria 3001

Telephone: (03) 9235 7256 Facsimile: (03) 9429 2583

Date May 2002

Publication Details

Koster, W. M. (2002). An assessment of the aquatic fauna in Gardiners, Scotchmans, Back and Damper creeks. Report to Melbourne Water. Freshwater Ecology Section, Department of Natural Resources and Environment, Melbourne.

Cover photographs (top to bottom): ! Damper Creek at Park Road ! Scotchmans Creek at Regent Street ! Gardiners Creek at Warrigal Road ! Back Creek at Dawson Drive ! Gardiners Creek at Glenferrie Road (All photos: W. Koster)

Department of Natural Resources and Environment – Freshwater Ecology An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Summary

Background To determine the health of streams in the Melbourne area and to identify priority management areas, Melbourne Water Corporation has established the Tributary Investigation Program combining a range of stream health indicators that are assessed at a variety of temporal and spatial scales. The Freshwater Ecology Section of the Department of Natural Resources and Environment was commissioned to undertake the aquatic fauna component of the Tributary Investigation Program in the Gardiners Creek catchment. The objective of this investigation was to provide an assessment of the current state of the aquatic fauna in the catchment and to identify the primary factors impacting on the condition of these communities.

Fish Surveys A total of ten survey sites were selected within the study region, in consultation with Melbourne Water. Five sites were selected on Gardiners Creek, three sites on Scotchmans Creek, and one site on each of Back and Damper creeks. Aquatic fauna surveys were conducted between the 25th of January and 1st of February 2002 using a portable backpack electrofishing unit. At each survey site a standard, two-pass electrofishing technique was used.

Species Distribution and Abundance

A total of 416 individual fish representing seven families and nine species (four native and five exotic) were collected during the aquatic fauna surveys. Two species of decapod crustacea were also recorded. At each site, the diversity of native species was low and represented less than 30% of the species expected to occur under natural conditions. Three of the four native species collected during these surveys were migratory species and require free passage between marine and freshwater environments at both adult and larval/juvenile stages of their life cycle.

The diversity and abundance of native species tended to be higher in the lower reaches of the catchment than in the upper reaches. The diversity and abundance of exotic species varied throughout the study area. In general, native species dominated fish communities in Scotchmans Creek and the lower reaches of Gardiners Creek, whilst in Back Creek and the middle to upper reaches of Gardiners Creek, exotic species dominated fish communities.

Department of Natural Resources and Environment – Freshwater Ecology i An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

The native common galaxias (Galaxias maculatus) were the most abundant species within the study region. Short-finned eel (Anguilla australis) and eastern gambusia (Gambusia holbrooki) were also relatively common. Broad-finned galaxias (Galaxias brevipinnis), flat-headed gudgeon (Philypnodon grandiceps), and the exotic yellow-fin goby (Acanthogobius flavimanus), goldfish (Carassius auratus), carp (Cyprinus carpio) and oriental weatherloach (Misgurnus anguillicaudatus) were all recorded in low numbers.

Condition of Aquatic Fauna Assemblages The rationale employed in this study to assess the condition of aquatic fauna assemblages uses a biotic index incorporating two parameters of aquatic fauna population dynamics; naturalness (species diversity) and exotic abundance. The condition of aquatic fauna assemblages varied throughout the study area, although the majority of sites were described as having degraded to moderate health. It appears that under certain circumstances the rationale used to assess the condition of aquatic fauna assemblages provides false assessment as it affords undue importance to the absence of exotic species when population naturalness is low. This result has been found in previous studies and requires modification if it is to be used in future.

Impacts on Environmental Condition This study has identified numerous factors impacting on environmental condition within the study area and more specifically on aquatic fauna assemblages. These include:

" Barriers to fish migration, " Introduction of exotic species, " Changes to stream channels, " Changes to water quality, " Clearing of riparian vegetation.

Department of Natural Resources and Environment – Freshwater Ecology ii An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

TABLE OF CONTENTS

SUMMARY...... i

1. INTRODUCTION...... 1

2. MATERIALS AND METHODS ...... 2

2.1 STUDY AREA ...... 2 2.2 STUDY SITES ...... 3 2.3 SAMPLING METHODOLOGY...... 3 2.3.1 Aquatic Fauna Survey...... 3 2.3.2 Quantification of Site Attributes...... 4 2.3.3 Analyses...... 5

3. RESULTS...... 6

3.1 HISTORICAL DATA ...... 6 3.2 GENERAL SURVEY RESULTS ...... 7 3.2.1 General Site Characteristics ...... 7 3.2.2 Site Specific Descriptions...... 11 3.2.3 Fish Survey Results ...... 21

4. DISCUSSION...... 29

4.1 SPECIES DIVERSITY, DISTRIBUTION AND ABUNDANCE ...... 29 4.2 HEALTH OF AQUATIC FAUNA ASSEMBLAGES ...... 30 4.3 IMPACTS ON AQUATIC FAUNA ...... 31 4.4 SIGNIFICANT SPECIES...... 33 4.5 RECOMMENDATIONS...... 34

5. ACKNOWLEDGMENTS...... 35

6. REFERENCES...... 36

7. APPENDIX A ...... 40

7.1 GARDINERS CREEK – GC1 ...... 40 7.2 GARDINERS CREEK – GC2 ...... 41 7.3 GARDINERS CREEK – GC3 ...... 42 7.4 GARDINERS CREEK – GC4 ...... 43 7.5 GARDINERS CREEK – GC5 ...... 44 7.6 BACK CREEK – BC1...... 45 7.7 SCOTCHMANS CREEK – SC1 ...... 46 7.8 SCOTCHMANS CREEK – SC2 ...... 47 7.9 SCOTCHMANS CREEK – SC3 ...... 48 7.10 DAMPER CREEK – DC1 ...... 49

Department of Natural Resources and Environment – Freshwater Ecology An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

1. INTRODUCTION

To determine the health of streams in the Melbourne area, and to identify priority management areas, Melbourne Water Corporation has established a stream health assessment program including ongoing monitoring programs such as the Biological Monitoring Program and the Tributary Investigation Program. These programs combine a range of stream health indicators that are assessed at a variety of temporal and spatial scales.

The Freshwater Ecology Section of the Department of Natural Resources and Environment was commissioned to undertake the aquatic fauna (fish and decapod crustacea) component of the Tributary Investigation Program in the Gardiners Creek catchment. The objective of this investigation was to provide an assessment of the current state of the aquatic fauna in the catchment and to identify the primary factors impacting on the condition of these communities.

There have been several previous studies examining the environmental health of streams in the Gardiners Creek catchment (Melbourne Water 1997, Hardwick and Waller 1999, Yarra Care 1999, Bessell-Browne 2000, Deveraux et al. 2000). A report by Melbourne Water (1997) on the health of waterways within the Gardiners Creek system described water quality and stream condition as poor and community health of aquatic macroinvertebrates as very poor to fair. Similarly, Bessell-Browne (2000) reported that no sites in Gardiners Creek complied with Waters of Victoria (WoV) Schedule F7 (Government of Victoria 1999) objectives for biological indicators and that some sites failed to comply with various physico-chemical objectives.

There have been few previous fish surveys conducted within the study region and therefore information on the distribution and abundance of aquatic fauna in the Gardiners Creek catchment is limited. This document provides a summary of historical fish surveys and a brief assessment of the current status (species diversity and abundance) of the fish assemblages in the Gardiners Creek catchment. Primary issues within the catchment likely to be impacting on the health of aquatic fauna populations are also identified.

Department of Natural Resources and Environment – Freshwater Ecology 1 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

2. MATERIALS AND METHODS

2.1 STUDY AREA

The Gardiners Creek catchment is located in the south-eastern suburbs of Melbourne in the lower reaches of the Yarra Basin (Figure 2-1). The catchment is urbanised and covers an area of approximately 11060 hectares (Poussard 1996). Gardiners Creek under natural conditions comprised a number of shallow channels through a swampy floor, fringed by dense thickets of swamp paperbark (Melaleuca ericifolia) (Duxbury 1990). As urbanisation of Melbourne progressed the creek environment dramatically changed, particularly due to stream channelisation and clearing of vegetation (Duxbury 1990). Gardiners Creek originates near Blackburn at an altitude of approximately 120 m.a.s.l., flowing for approximately 12 kilometres in a south-westerly direction, before travelling a further eight kilometres in a north-westerly direction prior to its confluence with the Yarra River near Hawthorn. A natural rock barrier on the lower reaches of the Yarra River near Queen Street, approximately five kilometres downstream of the Gardiners Creek confluence, historically represented the upstream limit of tidal influence (Piha 1992). During the 1860s the barrier was removed and consequently the tidal influence extended upstream and now the lower reaches of Gardiners Creek are tidally affected. Scotchmans Creek originates near Mount Waverley at an altitude of approximately 80 m.a.s.l., flowing for approximately 10 kilometres in a westerly direction before entering Gardiners Creek near East Malvern. The two other main streams in the catchment are Damper and Back creeks, located in the upper and lower reaches of the catchment respectively. Mean annual rainfall in the catchment is approximately 750 mm (Poussard 1996).

r Victoria

e # #

v # Blackburn

i Hawthorn R GC5$

# Yarra Blackburn Lake GC1$ k G e re a GC4 C r # Glen Iris $ d i GC2 ne $ Back Creek rs BC1$ # s r Waterways e Ashburton n Ashwood Damper Creek i # C # # r d $ # e r Locality e GC3 a DC1 k $ G $ Survey site SC1 $ # Mount Waverley East Malvern # $ S N c SC3 o t SC2 ch $ 1012Kilometers m k ans C r e e

Figure 2-1. Gardiners Creek catchment including location of aquatic fauna survey sites (Refer to Table 2-1 for site details).

Department of Natural Resources and Environment – Freshwater Ecology 2 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

2.2 STUDY SITES

A total of ten survey sites were selected within the study region, in consultation with Melbourne Water; five sites in Gardiners Creek, three sites in Scotchmans Creek, and one site in each of Back and Damper creeks (Figure 2-1, Table 2-1). At each site, a single survey reach was established to represent the available aquatic habitat attributes including flow types and cover elements. The location of each survey reach was defined by Australian Map Grid Reference (AMG) from topographic 1:25,000 scale maps (Table 2-1).

Table 2-1. Location of aquatic fauna survey sites on Gardiners, Scotchmans, Back and Damper creeks. Creek and Location Melway AMG Reference* Site Reference (eastings-northings) Gardiners GC1 Downstream of concrete channel, Glenferrie 59B2 326300-5810200 Road, Hawthorn GC2 Downstream of Tooronga Road, Malvern 59E5 327600-5809200 GC3 Downstream of Warrigal Road, Ashburton 60G12 332000-5806500 GC4 Downstream of Station Street, Burwood 61C4 334500-5809900 GC5 Upstream of Middleborough Road, Blackburn 47K11 335900-5811700 Back BC1 Downstream of Dawson Drive, Glen Iris 59K7 329300-5808400 Scotchmans SC1 Footbridge at Malvern Valley Golf Course, 69D1 330800-5806100 East Malvern SC2 Downstream of Huntingdale Road, 69K5 333400-5804500 Chadstone SC3 Upstream of Regent Street, Mount Waverley 70G3 336100-5805100 Damper DC1 Upstream of Park Road, Mount Waverley 61D11 334900-5807100 * - Map number 7922, zone 55.

2.3 SAMPLING METHODOLOGY

2.3.1 Aquatic Fauna Survey

Aquatic fauna surveys were conducted between January 25th and February 1st 2002 using a portable backpack Smith-Root® model 12 electrofishing unit. At all sites a standard, two- pass electrofishing technique, with stop nets (5 mm stretched mesh) positioned at the upstream and downstream margins of the survey reach, was used. This technique is identical with that used in all other stream health assessments conducted by Freshwater Ecology for Melbourne Water (Raadik and O’Connor 1997, Raadik and Zampatti 1998, Raadik and Lieschke 1999, Raadik et al., 1999, Lieschke and Raadik 1999, Close 2000, Close et al. 2001). The operator fished upstream from the downstream stop net, fishing all habitats along the edges and in the middle of the channel, stunning and retrieving fish. An assistant followed the operator collecting any animals missed by the operator.

Department of Natural Resources and Environment – Freshwater Ecology 3 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

All fish recorded were identified and counted. For samples containing many (>30) individuals of a single species, a representative subsample of 20 specimens was measured for length (to the nearest 1 mm - length to caudal fork) and weight (wet weight to the nearest 0.1 g for weights < 100 g and 1 g for weights > 100g). The number and bulk weight for additional individuals of each species was also recorded. Nomenclature for fish species follows Allen (1989), Paxton et al. (1990), McDowall (1997) and Jerry et al. (2001), Riek (1969) and Horwitz (1990) for decapod crustacea, and Williams & Smith (1979) for freshwater shrimps.

2.3.2 Quantification of Site Attributes

Hydrology

For each survey reach the average width (m) was calculated from at least five measurements. Average depth (m) within each survey reach was calculated from depth measurements taken across at least five transects strategically positioned to incorporate a representative sample of depths. Spot measurements of water quality parameters were recorded within each survey reach. Water temperature (ºC) and electrical conductivity (µS.cm-1) were measured with a WTW LF 320 meter, dissolved oxygen (mg.L-1) with a WTW OXI 320 meter, turbidity (NTU) with a HACH 2100P Turbidimeter and pH with a WTW pH 320 meter.

A measure of instantaneous discharge was recorded for each survey reach on the day of survey. A cross-channel transect, perpendicular to the flow, was established at specific locations in the vicinity of each survey reach and preferably downstream. Discharge transects were located where channel morphology was uniform in terms of flow, depth, width and slope and in areas with minimal upstream obstacles such as rocks, logs or macrophyte beds. Any upstream obstacles were temporarily removed to increase laminar flow and avoid turbulence, eddies and dead-water zones. Instantaneous discharge was estimated using depth and flow measurements taken across discharge transects according to the methodology outlined in Gordon et al. (1992). Using the equation below, instantaneous discharge was calculated and expressed in megalitres per day (ML.d-1).

= + + + Q w1 D1v1 w2 D2 v2 ...... wn Dn vn Where w is width in metres, D is vertical depth in metres and v is the average velocity

Habitat Attributes

The relative abundance (% of wetted area) of hydraulic flow components, habitat attributes and cover elements was estimated for each survey reach. Hydraulic flow type at each site was defined using the categories; cascade, rapid, riffle, glide, run, pool or backwater (after

Department of Natural Resources and Environment – Freshwater Ecology 4 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Anderson & Morrison 1989, Anderson et al. 1989). Streambed geology was described in terms of percentage composition of various particle size groups, namely boulder (particle size > 256 mm), cobble (64-255 mm particle size), pebble (16-63 mm particle size), gravel (2-15 mm particle size), sand (0.1-2 mm particle size) and silt/clay (particle size < 0.1 mm). The relative abundance of dominant cover elements including substratum, woody debris (logs, branches), organic debris (leaves, bark), bank overhang, vegetation overhang and aquatic vegetation was recorded.

2.3.3 Analyses

Catch per unit effort, biomass and density

An estimate of catch per unit effort (CPUE) was calculated for each site and expressed in terms of the number of fish recorded per hour. The summed time of two electrofishing passes was used in the calculation of CPUE. Estimates of biomass (g.m-2) and density (fish.m-2) were also calculated for each site.

Stream health

The rationale implemented in this study for assessing the condition of aquatic fauna assemblages is consistent with the methods used in previous "Tributary Investigation" surveys. Condition was assessed based on two indicators; the naturalness of fish and the relative abundance of exotic species at each site. The naturalness of aquatic fauna populations was expressed in terms of the proportion (%) of native species recorded at each site of the total number of native species expected to occur at each site under natural conditions. The list of expected taxa for each site was compiled using historical distribution data (DNRE 2002). As only a few fish surveys have been conducted in the study area, the list of expected taxa was further refined using expert knowledge of the distribution and habitat requirements of Victorian fish species. Both indicators of stream health (naturalness and relative abundance of exotic species) were ranked according to the criteria in Table 2-2. The two ranks were then summed to provide an indication of condition (Table 2-2). As little distributional data is available for decapod crustacea in the study area, they were omitted from the assessment.

Table 2-2. Category, rank and description of stream assessment indicators; naturalness (A) exotic species abundance (B) and stream health assessment (A+B). Naturalness (A) Exotic abundance (B) Stream health (A+B) Category Rank Description Category Rank Description Rank Description 80–100 % 9 Excellent 0 % 9 Excellent >14 Excellent 61–80 % 7 Good 1-9 % 7 Good 10-14 Good 31–60 % 3 Moderate 10-29 % 5 Moderate 7-9 Moderate 1–30 % 1 Poor 30-69 % 3 Poor 4-6 Poor 0 % 0 Degraded 70-100 % 0 Degraded 0-3 Degraded

Department of Natural Resources and Environment – Freshwater Ecology 5 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

3. RESULTS

3.1 HISTORICAL DATA

Thirteen species of freshwater fish have been reported from the Gardiners Creek catchment (DNRE 2002, Museum of Victoria - MV) (Table 3-1). Six of these species are native, including at least one species that migrates between freshwater and marine habitats at some stage in its life cycle, namely short-finned eel (Anguilla australis) (Table 3-1). An unidentified galaxias species reported from Blackburn Lake is likely to represent an additional native migratory species. One species of decapod crustacea has also been reported (Table 3-1). One of the native species, namely dwarf galaxias (Galaxiella pusilla), is classified as ‘lower-risk - near threatened’ in Victoria (DNRE 2000) and ‘vulnerable’ nationally (ANZECC 2000), and protected through their listing on the Flora and Fauna Guarantee Act 1988 and the Environment Protection and Biodiversity Conservation Act 1999.

Table 3-1. Native and exotic freshwater fish species previously recorded from the Gardiners Creek catchment. Scientific name Common Name Location Native fish species Anguilla australis Short-finned eel Blackburn Lake Galaxias spp. Blackburn Lake Galaxiella pusilla Dwarf galaxias Scotchmans Creek, Oakleigh Gadopsis marmoratus River blackfish Gardiners Creek, Malvern East Nannoperca australis Southern pygmy perch Scotchmans Creek, Oakleigh Retropinna semoni Australian smelt Blackburn Lake Exotic fish species Gambusia holbrooki Eastern gambusia Blackburn Lake Salmo trutta Brown trout Gardiners Creek, Malvern East Carassius auratus Goldfish Blackburn Lake Misgurnus anguillicaudatus Oriental weatherloach Gardiners Creek, Malvern East Rutilus rutilus Roach Blackburn Lake Cyprinus carpio Carp Blackburn Lake Perca fluviatilis Redfin Blackburn Lake Decapod crustacea Cherax destructor Common yabby Blackburn Lake

Few fish surveys have been documented within the study region (DNRE 2002). Most surveys were conducted before 1990 and none have been conducted in Back or Damper creeks (DNRE 2002). River blackfish (Gadopsis marmoratus) and brown trout (Salmo trutta) were recorded in Gardiners Creek near High Street, Malvern East, ca. 1950 (DNRE 2002). Roach (Rutilus rutilus), redfin (Perca fluviatilis) and goldfish (Carassius auratus) were recorded in Blackburn Lake in 1973, ca. 1987, and 1988 (DNRE 2002). Dwarf galaxias and southern pygmy perch (Nannoperca australis) were recorded in

Department of Natural Resources and Environment – Freshwater Ecology 6 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Scotchmans Creek, Oakleigh, pre-1985 (MV). This record of dwarf galaxias represents the only documented record of the species in the Yarra River basin (DNRE 2002). Short-finned eel, galaxias spp., eastern gambusia (Gambusia holbrooki) and carp (Cyprinus carpio) were recorded in Blackburn Lake, ca. 1988 (DNRE 2002). Oriental weatherloach (Misgurnus anguillicaudatus) were recorded in Gardiners Creek near Burke Road, Glen Iris, 1991 (DNRE 2002). Australian smelt (Retropinna semoni) and common yabby (Cherax destructor) were recorded in Blackburn Lake in 1993 (Deveraux et al. 2000).

3.2 GENERAL SURVEY RESULTS

3.2.1 General Site Characteristics

Gardiners Creek

The five survey sites located on Gardiners Creek were positioned reasonably evenly throughout the catchment in terms of altitude and distance to river mouth (Table 3-2). Reach characteristics varied between sites (Table 3-2). Average stream width generally decreased with distance upstream, ranging from 11.3 m at the most downstream site (GC1) to 3.5 m at the most upstream site (GC5). Average stream depth was less than 0.5 m at all sites, except at the second most upstream site (GC4) where the average stream depth was 1.0 m.

Physico-chemical water quality parameters are shown in Table 3-2. Water temperature ranged from 19.0ºC at the second most downstream site (GC2) to 34.2ºC at the mid-reach site (GC3). Electrical conductivity concentrations were highest (273.0 µS.cm-1) at the most downstream site (GC1) and lowest (50.1 µS.cm-1) at the most upstream site (GC5). Dissolved oxygen concentrations were highest (9.7 mg.L-1) at the mid-reach site (GC3) and lowest (4.6 mg.L-1) at the most downstream site (GC1). Turbidity ranged from 4.4 NTU at the mid-reach site (GC3) to 17.7 NTU at the second most upstream site (GC4). At most sites pH was close to neutral (6.8 to 7.1), except at the mid-reach site where the level was 9.9. At the time of survey, stream discharge ranged from 2.1 ML.d-1 (GC5) to 5.4 ML.d-1 (GC3).

The streambed at all sites comprised varying amounts of both fine (e.g. sand) and coarse substratum (e.g. gravel, boulder) (Table 3-2). At all sites sand and gravel comprised at least 50% of the substrate. Silt and clay were only present in small quantities in the upper catchment (sites GC4, GC5). Coarse substrata (e.g. pebbles, cobble, boulder) tended to become more abundant with increasing distance downstream from source. The occurrence of coarse substrata in the mid to lower reaches of the catchment appears to be associated with stream restoration works, specifically stabilisation of the streambed and banks. Instream cover at all sites comprised predominantly rock (20-40%), except at the second most upstream site (GC4) where aquatic vegetation was dominant (30%) (Table 3-2). The

Department of Natural Resources and Environment – Freshwater Ecology 7 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks hydrology at all sites was dominated by pool habitat (80-100%), except at the mid-reach site (GC3) where riffle was the dominant flow type (70%) (Table 3-2).

Table 3-2. Stream habitat survey information and habitat structure at each of the study sites located in Gardiners Creek. Substrata and instream cover are defined in the text. Habitat Survey Characteristics GC1 GC2 GC3 GC4 GC5 Stream characteristics Elevation (m.a.s.l.) 20 20 40 60 80 Distance to river mouth (km)* 0.5 3.0 10.0 15.0 18.0 Discharge (ML.d-1) 4.0 4.1 5.4 5.2 2.1 Reach characteristics Mean stream width (m) 11.3 5.3 4.8 5.8 3.5 Mean depth (m) 0.4 0.3 0.2 1.0 0.4 Water quality Temperature (ºC) 19.7 19.0 34.2 20.1 20.5 Electrical conductivity (µS.cm-1) 273.0 70.7 148.6 98.2 50.1 Dissolved oxygen (mg.L-1) 4.6 6.4 9.7 4.8 6.9 Turbidity (NTU) 8.8 6.2 4.4 17.7 15.6 pH 7.1 6.8 9.9 6.9 6.9 Substrate composition (%) Sheet rock 0 10 5 0 20 Boulder 10 20 25 20 0 Cobble 10 20 10 0 0 Pebble 30 0 0 0 0 Gravel 30 25 30 10 30 Sand 20 25 30 60 40 Silt 0 0 0 10 0 Clay 0 0 0 0 10 Instream cover (% wetted area) Substrate (Rock) 20 40 40 20 20 Logs/Log jams 0 0 0 0 0 Branches/Branch piles 0 0 0 0 5 Leaves, organic debris 0 2 5 10 5 Bank overhang 0 0 0 0 0 Vegetation overhang 0 0 0 0 5 Urban rubbish 0 0 0 0 0 Aquatic vegetation 1 5 1 30 5 Flow type (%) Rapid/cascade 0 0 0 0 0 Run 055010 Riffle 2 15 70 0 5 Glide 0 02505 Pool 98 80 0 100 80 Backwater 00000 * - Confluence of Gardiners Creek and Yarra River.

Department of Natural Resources and Environment – Freshwater Ecology 8 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Back Creek

The one survey site on Back Creek was located in the lower reaches of the catchment, approximately 300 m upstream from its confluence with Gardiners Creek. Physico-chemical water quality parameters are shown in Table 3-3. At the time of survey, stream discharge was zero ML.d-1. The streambed at Back Creek was dominated by fine substrata including sand and clay (Table 3-3). Instream habitat was scarce although small amounts of coarse substratum (rock), overhanging vegetation and bank and aquatic vegetation were present (Table 3-3). Flow type comprised predominantly pool habitat (Table 3-3).

Scotchmans Creek

The three survey sites located on Scotchmans Creek were positioned reasonably evenly throughout the catchment in terms of altitude and distance to river mouth (Table 3-3). Reach characteristics were similar at each site although the mid-reach site (SC2) was slightly narrower than the other two sites (Table 3-3).

Physico-chemical water quality parameters are shown in Table 3-3. Water temperature and electrical conductivity concentrations decreased with increasing distance upstream. Water temperature ranged from 20.5ºC at the most downstream site (SC1) to 18.7ºC at the most upstream site (SC3). Electrical conductivity concentrations ranged from 182.1 µS.cm-1 at the most downstream site (SC1) to 107.8 µS.cm-1 at the most upstream site (SC3). Dissolved oxygen concentrations were highest (7.9 mg.L-1) at the most downstream site (SC1) and lowest (2.9 mg.L-1) at the mid-reach site (SC2). Turbidity ranged from 3.1 NTU at the mid-reach site (SC2) to 8.4 NTU at the most upstream site (SC3). The level of pH (6.9 to 7.2) was close to neutral at all sites. At the time of survey, stream discharge ranged from 0.7 ML.d-1 (SC3) to 1.0 ML.d-1 (SC2).

The streambed at all sites comprised varying amounts of both fine (e.g. sand) and coarse substratum (e.g. gravel, boulder) (Table 3-3). At all sites sand and gravel comprised at least 40% of the substratum. Silt was only present in small quantities in the upper catchment (site SC3). Instream cover was scarce at the most upstream (SC3) and downstream (SC1) sites, while at the mid-reach site (SC2) aquatic vegetation was abundant (60%) (Table 3-3). The hydrology at all sites was dominated by pool habitat (70-80%) (Table 3-3).

Damper Creek

The one survey site on Damper Creek was located in the upper reaches of the catchment. Physico-chemical water quality parameters are shown in Table 3-3. At the time of survey, stream discharge was zero ML.d-1. The streambed at Damper Creek comprised approximately equal proportions of fine (e.g. sand, silt) and coarse (boulder, cobble) substrata (Table 3-3). Instream habitat was abundant and comprised aquatic vegetation, rock and vegetation overhang (Table 3-3). Flow type comprised predominantly pool habitat (Table 3-3).

Department of Natural Resources and Environment – Freshwater Ecology 9 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Table 3-3. Stream habitat survey information and habitat structure at each of the study sites located in Scotchmans, Back and Damper creeks. Substrata and instream cover are defined in the text. Habitat Survey Characteristics Site Site Site Site Site BC1 SC1 SC2 SC3 DC1 Stream characteristics Elevation (m.a.s.l.) 20 40 60 80 80 Distance to river mouth (km)* 5.0 8.0 12.0 16.0 - Discharge (ML.d-1) 0 0.8 1.0 0.7 0 Reach characteristics Mean stream width (m) 4.9 2.9 1.7 3.0 1.7 Mean depth (m) 0.5 0.3 0.3 0.3 0.1 Water quality Temperature (ºC) 20.3 20.5 18.9 18.7 19.4 Electrical conductivity (µS.cm-1) 235.0 182.1 127.7 107.8 51.1 Dissolved oxygen (mg.L-1) 2.6 7.9 2.9 3.3 3.0 Turbidity (NTU) 9.6 3.3 3.1 8.4 3.4 pH 7.1 7.2 6.9 7.1 6.8 Substrate composition (%) Sheet rock 0 0 0 0 0 Boulder 15 10 10 10 20 Cobble 5 10 20 10 30 Pebble 0 5 0 20 0 Gravel 5 20 30 30 10 Sand 40 20 30 10 20 Silt 5 0 0 10 20 Clay 303510100 Instream cover (% wetted area) Substrate (Rock) 10 10 5 10 10 Logs/Log jams 0 0 0 0 0 Branches/Branch piles 0 0 0 0 0 Leaves, organic debris 0 0 2 0 0 Bank overhang 5 0 0 10 0 Vegetation overhang 1 0 5 0 5 Urban rubbish 2 5 0 0 0 Aquatic vegetation 1 10 60 5 70 Flow type (%) Rapid/cascade 0 0 0 0 0 Run 0 51000 Riffle 2 15 0 30 20 Glide 0 01000 Pool 98 80 80 70 80 Backwater 00000 * - Confluence of Gardiners Creek and Yarra River.

Department of Natural Resources and Environment – Freshwater Ecology 10 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

3.2.2 Site Specific Descriptions

Gardiners Creek downstream of Glenferrie Road, Hawthorn

This reach was located downstream of Glenferrie Road, below a concrete channelised stream section, and extended from the base of a concrete weir wall to 100 m downstream (Figure 3-1). The site was dominated by pool habitat (98%) and the reach was tidally influenced. Average stream width and depth were 11.3 m and 0.4 m respectively. The riparian vegetation comprised mostly exotic grasses (50%) and some native trees (10%) and exotic shrubs (5%). A large proportion of the riparian zone comprised bare ground (45%). The streambed comprised predominantly pebble (30%), gravel (30%) and sand (20%). Instream habitat available as cover to aquatic fauna comprised coarse substratum (20%) and aquatic vegetation (1%). Streamside disturbances included a cleared riparian zone, a bridge, urban rubbish, a concrete weir and channel, and exotic vegetation.

Figure 3-1. Gardiners Creek downstream of Glenferrie Road, Hawthorn.

Department of Natural Resources and Environment – Freshwater Ecology 11 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Gardiners Creek downstream of Tooronga Road, Malvern

This reach extended from immediately below the bridge on Tooronga Road to 100 m downstream (Figure 3-2). Hydraulic habitats included pool (80%), riffle (15%) and run (5%). Average stream width and depth were 5.3 m and 0.3 m respectively. The riparian vegetation comprised mostly native trees (60%) and exotic grasses (20%). The streambed comprised predominantly gravel and sand (50% combined), and boulder and cobble (40% combined). Instream habitat available as cover to aquatic fauna comprised coarse substratum (40%), aquatic vegetation (5%) and organic debris (2%). Streamside disturbances included a bridge, a drain, urban rubbish and exotic vegetation.

Figure 3-2. Gardiners Creek downstream of Tooronga Road, Malvern.

Department of Natural Resources and Environment – Freshwater Ecology 12 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Gardiners Creek downstream of Warrigal Road, Ashburton

This reach extended from approximately 10 m to 110 m downstream of the bridge on Warrigal Road (Figure 3-3). Hydraulic habitat included riffle (70%), glide (25%) and run (5%). Average stream width and depth were 4.8 m and 0.2 m respectively. The riparian vegetation comprised mostly exotic grasses (60%) and native trees and shrubs (30% combined). The streambed comprised predominantly gravel and sand (60% combined) and boulder (25%). Instream habitat available as cover to aquatic fauna comprised coarse substratum (40%), organic debris (5%) and aquatic vegetation (1%). Streamside disturbances included a bridge, cleared riparian zone, a drain, urban rubbish, exotic vegetation and concrete channel.

Figure 3-3. Gardiners Creek downstream of Warrigal Road, Ashburton.

Department of Natural Resources and Environment – Freshwater Ecology 13 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Gardiners Creek downstream of Station Street, Burwood

This reach extended from immediately below the bridge on Station Street to 100 m downstream (Figure 3-4). The hydrology was dominated by pool habitat (100%). Average stream width and depth were 5.8 m and 1.0 m respectively. The riparian vegetation comprised mostly exotic grasses (90%). The streambed comprised predominantly sand (60%) and boulder (20%). Instream habitat available as cover to aquatic fauna comprised aquatic vegetation (30%), rock (20%) and organic debris (10%). Streamside disturbances included a bridge, a drain, cleared riparian zone, urban rubbish and exotic vegetation.

Figure 3-4. Gardiners Creek downstream of Station Street, Burwood.

Department of Natural Resources and Environment – Freshwater Ecology 14 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Gardiners Creek upstream of Middleborough Road, Blackburn

This reach extended from the culvert at Middleborough Road to 100 m upstream (Figure 3-5). Hydraulic habitats included pool (80%), run (10%), riffle (5%) and glide (5%). Average stream width and depth were 3.5 m and 0.4 m respectively. The riparian vegetation comprised mostly exotic grasses (50%) and native trees (30%). The streambed comprised predominantly sand (40%), gravel (30%) and sheetrock (20%). Instream habitat available as cover to aquatic fauna comprised coarse substratum (20%), branches (5%), organic debris (5%), vegetation overhang (5%) and aquatic vegetation (5%). Streamside disturbances included bank erosion, a cleared riparian zone, a culvert and exotic vegetation.

Figure 3-5. Gardiners Creek upstream of Middleborough Road, Blackburn.

Department of Natural Resources and Environment – Freshwater Ecology 15 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Back Creek downstream of Dawson Drive, Glen Iris

This reach extended from the culvert on Dawson Drive to 100 m downstream (Figure 3-6). The hydrology was dominated by pool habitat (98%). Average stream width and depth were 4.9 m and 0.5 m respectively. The riparian vegetation comprised mostly willows (50%) and exotic creepers and grasses (45% combined). The streambed comprised predominantly sand (40%) and clay (30%). Instream habitat available as cover to aquatic fauna comprised coarse substratum (10%), bank overhang (5%), vegetation overhang (1%) and aquatic vegetation (1%). Streamside disturbances included a cleared riparian zone, a culvert, urban rubbish, a drain and exotic vegetation.

Figure 3-6. Back Creek downstream of Dawson Drive, Glen Iris.

Department of Natural Resources and Environment – Freshwater Ecology 16 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Scotchmans Creek at Malvern Valley Golf Course, East Malvern

This reach was located on the Malvern Valley Golf Course and extended 100 m upstream of the footbridge (Figure 3-7). Hydraulic habitats included pool (80%), riffle (15%) and run (5%). Average stream width and depth were 2.9 m and 0.3 m respectively. The riparian vegetation comprised mostly exotic grasses (60%) and exotic trees (20%). The streambed comprised predominantly clay (35%), gravel (20%) and sand (20%). Instream habitat available as cover to aquatic fauna comprised aquatic vegetation (10%), coarse substratum (10%) and urban rubbish (5%). Streamside disturbances included bank erosion, a cleared riparian zone, a bridge, exotic vegetation and concrete channel.

Figure 3-7. Scotchmans Creek at Malvern Valley Golf Course, East Malvern.

Department of Natural Resources and Environment – Freshwater Ecology 17 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Scotchmans Creek downstream of Huntingdale Road, Chadstone

This reach extended from approximately 25 m to 125 m downstream of the culvert at Huntingdale Road (Figure 3-8). Hydraulic habitats included pool (80%), run (10%) and glide (10%). Average stream width and depth were 1.7 m and 0.3 m respectively. The riparian vegetation comprised mostly exotic grasses (80%) and native trees and shrubs (20% combined). The streambed comprised predominantly gravel (30%), sand (30%) and cobble (20%). Instream habitat available as cover to aquatic fauna comprised aquatic vegetation (60%), coarse substratum (5%), vegetation overhang (5%) and organic debris (2%). Streamside disturbances included a cleared riparian zone, urban rubbish, a culvert, exotic vegetation and a drain.

Figure 3-8. Scotchmans Creek downstream of Huntingdale Road, Chadstone.

Department of Natural Resources and Environment – Freshwater Ecology 18 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Scotchmans Creek upstream of Regent Street, Mount Waverley This reach extended from the culvert at Regent Street to approximately 100 m upstream (Figure 3-9). Hydraulic habitats included pool (70%) and riffle (30%). Average stream width and depth were 3.0 m and 0.3 m respectively. The riparian vegetation comprised mostly exotic grasses (45%), willows (40%) and native trees and shrubs (20% combined). The streambed comprised predominantly pebble and gravel (60% combined). Instream habitat available as cover to aquatic fauna comprised coarse substratum (10%), bank overhang (10%) and aquatic vegetation (5%). Streamside disturbances included a cleared riparian zone, a culvert, exotic vegetation, a section of bluestone channel, and a drain.

Figure 3-9. Scotchmans Creek upstream of Regent Street, Mount Waverley.

Department of Natural Resources and Environment – Freshwater Ecology 19 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Damper Creek upstream of Park Road, Mount Waverley

This reach extended from the culvert on Park Road to approximately 100 m upstream (Figure 3-10). Hydraulic habitats included pool (80%) and riffle (20%). Average stream width and depth were 1.7 m and 0.1 m respectively. The riparian vegetation comprised mostly native shrubs and trees (85% combined). The streambed comprised predominantly cobble (30%), boulder (20%), sand (20%) and silt (20%). Instream habitat available as cover to aquatic fauna comprised aquatic vegetation (70%), rock (10%) and vegetation overhang (5%). Streamside disturbances included a culvert and exotic vegetation.

Figure 3-10. Damper Creek upstream of Park Street, Mount Waverley.

Department of Natural Resources and Environment – Freshwater Ecology 20 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

3.2.3 Fish Survey Results

Species diversity and abundance

A total of 416 individual fish representing seven families and nine species were recorded during the aquatic fauna surveys (Table 3-4, 3-5). Four native species were collected, three of which are migratory1 (Table 3-4). Two species of decapod crustacea were also recorded (Table 3-4). Native fish species contributed 66% of the total fish fauna recorded, and overall, native migratory fish contributed 61% of the total fish fauna recorded, native non- migratory fish 5% and exotic fish 34% (Table 3-5). In general, the majority of native migratory fish species were recorded in the lower reaches of the study area (Table 3-5). None of the native species are considered threatened in Victoria (DCNR 1995, DNRE 2000).

Table 3-4. Aquatic fauna recorded in Gardiners, Scotchmans, Back and Damper creeks. Scientific name Common name Gardiners Back Scotchmans Damper Native fish species Anguilla australis* Short-finned eel ✔✔ ✔ Galaxias brevipinnis* Broad-finned galaxias ✔✔ Galaxias maculatus* Common galaxias ✔✔ ✔ Philypnodon grandiceps Flat-headed gudgeon ✔ Exotic fish species Acanthogobius flavimanus Yellow-fin goby ✔ Carassius auratus Goldfish ✔ Cyprinus carpio Carp ✔ Gambusia holbrooki Eastern gambusia ✔✔ ✔ Misgurnus anguillicaudatus Oriental weatherloach ✔✔ ✔ Decapod crustacea Cherax destructor Common yabby ✔✔ Paratya australiensis Freshwater shrimp ✔ ✔- Species present. * - Migrates between freshwater and marine habitats at some stage in life cycle.

The number of fish species recorded at each site varied, ranging from zero species at Damper Creek (DC1) to five species at the mid-reach and most downstream site on Gardiners Creek (GC3 and GC1 respectively) (Table 3-5). The number of individual fish recorded at each site also varied, ranging from zero individuals at Damper Creek (DC1) to 97 individuals at the second most downstream site on Gardiners Creek (GC2) (Table 3-5).

In Gardiners Creek, the number of fish species recorded at each site ranged from three species at the most upstream (GC5) and second most downstream (GC2) sites to five species at the mid-reach (GC3) and most downstream (GC1) sites (Table 3-5). The number

1 Require free passage between marine and freshwater environments at both adult and larval/juvenile stages of their life cycle.

Department of Natural Resources and Environment – Freshwater Ecology 21 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks of individuals recorded at each site ranged from five at the most upstream site (GC5) to 97 at the second most downstream site (GC2) (Table 3-5).

Twenty-seven fish representing three species were recorded at Back Creek (BC1) (Table 3-5). In Scotchmans Creek, the number of fish species and individuals recorded at each site increased with increasing distance downstream from source (Table 3-5). Four individuals of one species were collected at the most upstream site (SC3), 15 fish representing three species were recorded at the mid reach site (SC2), while 74 fish representing four species were recorded at the downstream site (SC1) (Table 3-5).

In terms of abundance, common galaxias (Galaxias maculatus) were the dominant species with 176 individual fish recorded (Table 3-5). Short-finned eel and the exotic eastern gambusia were also relatively common; 72 and 79 individuals respectively (Table 3-5). Low numbers of broad-finned galaxias (Galaxias brevipinnis), flat-headed gudgeon (Philypnodon grandiceps), yellow-fin goby (Acanthogobius flavimanus), goldfish, carp and oriental weatherloach were also recorded (five to 23 individuals) (Table 3-5).

In Gardiners Creek, the fish assemblage at the most downstream site (GC1) comprised approximately equal abundances of short-finned eel (33%), common galaxias (25%) and flat-headed gudgeon (23%) (Table 3-5, 3-6). At the second most downstream site (GC2) common galaxias and short-finned eel dominated the fish assemblage with relative abundances of 71% and 26% respectively (Table 3-5, 3-6). The fish assemblage at the mid- reach site (GC3) comprised approximately equal abundances of common galaxias (34%), goldfish (29%) and eastern gambusia (29%) (Table 3-5, 3-6). At the second most upstream site (GC4) eastern gambusia dominated the fish assemblage (75%) (Table 3-5, 3-6). The fish assemblage at the most upstream site (GC5) comprised approximately equal abundances of broad-finned galaxias (20%), eastern gambusia (40%) and oriental weatherloach (40%) (Table 3-6).

In Back Creek, the fish assemblage was dominated by oriental weatherloach (59%) and short-finned eel (37%) (Table 3-5, 3-6). A single common galaxias was also recorded (Table 3-5). In Scotchmans Creek, the fish assemblage at the most downstream site (SC1) was dominated by common galaxias (93%), although short-finned eel, eastern gambusia and oriental weatherloach were also recorded (Table 3-5, 3-6). The fish assemblage at the mid-reach site (SC2) comprised approximately equal abundances of short-finned eel (27%), common galaxias (40%) and eastern gambusia (33%) (Table 3-5, 3-6). At the most upstream site on Scotchmans Creek (SC3), only one species, namely broad-finned galaxias, was recorded (Table 3-5).

Department of Natural Resources and Environment – Freshwater Ecology 22 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Summary of species distribution

Common galaxias were the most abundant species recorded, comprising 42% of the total fish fauna recorded, and were also one of the most widespread species, being recorded at six of the 10 survey sites (Table 3-5). In both Gardiners and Scotchmans creeks, the highest numbers of common galaxias were recorded from sites located in the lower reaches of the study area (GC1, GC2 and SC1) (Table 3-5).

Short-finned eel comprised 17% of the total fish fauna recorded, and were also one of the most widespread species, being recorded at the six survey sites where common galaxias were recorded (Table 3-5). In Gardiners Creek, the highest numbers of short-finned eel were recorded from sites located in the lower reaches of the study area (GC1 and GC2) (Table 3-5).

Broad-finned galaxias were recorded in relatively low numbers from the most upstream site on both Gardiners and Scotchmans creeks (GC5 and SC3) (Table 3-5). Flat-headed gudgeon were only recorded at the most downstream site on Gardiners Creek (GC1) and comprised 23% of the fish fauna recorded at this site (Table 3-5).

Eastern gambusia were the most widespread species, being recorded at seven of the 10 survey sites, and comprised 19% of the total fish fauna recorded (Table 3-5). The majority (75%) of eastern gambusia were recorded at the second most upstream site on Gardiners Creek (GC4) (Table 3-5).

Oriental weatherloach were recorded in relatively low numbers from three sites in the mid to upper reaches of Gardiners Creek (GC3, GC4 and GC5), the most downstream site in Scotchmans Creek (SC1) and Back Creek (BC1) (Table 3-5). The majority (70%) of oriental weatherloach were recorded at Back Creek (BC1) (Table 3-5).

Goldfish were only recorded in relatively low numbers from sites located in the mid to upper reaches of Gardiners Creek (GC3 and GC4) (Table 3-5). Carp were only recorded at the second most upstream site on Gardiners Creek (GC4), comprising 18% of the fish fauna recorded at this site (Table 3-5). Yellow-fin goby were only recorded at the most downstream site on Gardiners Creek (GC1), comprising 15% of the fish fauna recorded at this site (Table 3-5).

Department of Natural Resources and Environment – Freshwater Ecology 23 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Table 3-5. Total abundance of species recorded at sites on Gardiners, Scotchmans, Back and Damper creeks. Species GC1 GC2 GC3 GC4 GC5 BC1 SC1 SC2 SC3 DC1 Total Native fish species Anguilla australis* 31 25 1 10 1 4 72 Galaxias brevipinnis*145 Galaxias maculatus* 24 69 7 1 69 6 176 Philypnodon grandiceps 22 22 Exotic fish species Acanthogobius flavimanus 14 14 Carassius auratus 65 11 Cyprinus carpio 14 14 Gambusia holbrooki 336592 15 79 Misgurnus anguillicaudatus 112163 23 Decapod crustacea Cherax destructor 1 61 7 38 8 115 Paratya australiensis ✔ Total number of individuals 94 98 82 86 43 27 82 15 4 0 531 Total number of species 547543531011 ✔- Species present. * - Migrates between freshwater and marine habitats at some stage in life cycle.

Department of Natural Resources and Environment – Freshwater Ecology 24 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Survey Effort

Survey effort (time in hours) varied at each site depending on stream size and habitat complexity and ranged from 0.7 hours at Damper Creek (DC1) and the most upstream site on Scotchmans Creek (SC3) to 1.4 hours at the most downstream site on Gardiners Creek (GC1) (Table 3-6). The area of each survey reach also varied between sites (Table 3-6).

Fish Density and Biomass

Fish density was low at all sites (0-0.25 fish.m-2), while fish biomass varied between sites (0-50.5 g.m-2) with no apparent spatial trend (Table 3-6). In Gardiners Creek, fish biomass ranged from 0.03 g.m-2 at the most upstream site (GC5) to 50.5 g.m-2 at the second most upstream site (GC4) (Table 3-6). At the two most upstream sites on Gardiners Creek (GC4 and GC5), exotic species comprised the majority of fish biomass; carp comprised 99% at GC4, and oriental weatherloach comprised 61% and eastern gambusia 21% at GC5. At the three most downstream sites on Gardiners Creek (GC1, GC2 and GC3), short-finned eel comprised the majority of fish biomass; 98%, 99% and 74% respectively. In Back Creek (BC1), short-finned eel comprised the majority of fish biomass (95%). In Scotchmans Creek, fish biomass ranged from 0.2 g.m-2 at the most upstream site (SC3) to 6 g.m-2 at the mid-reach site (SC2) (Table 3-6). At all sites on Scotchmans Creek, native species comprised the majority of fish biomass; common galaxias comprised 66% at SC1, short- finned eel 97% at SC2, and broad-finned galaxias comprised 100% at SC3.

Catch Per Unit Effort

Catch per unit effort (CPUE) varied between sites (0-92 fish.hr-1) (Table 3-6). In Gardiners and Scotchmans creeks, CPUE at the most upstream site on both creeks (GC5 and SC3) were similar (5.8-6 fish.hr-1). In Gardiners Creek, CPUE varied between sites with no apparent spatial trend (Table 3-6). In Scotchmans Creek, CPUE increased with increasing distance downstream from source, due to higher abundances of native migratory species in the lower reaches (Table 3-6).

Department of Natural Resources and Environment – Freshwater Ecology 25 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Table 3-6. Survey effort and area of survey reach and catch statistics for survey sites within the study region.

Creek and Site Effort Area Relative Abundance Density Biomass CPUE (hrs) (m-2) (%) (fish.m-2) (fish g.m-2) (fish.hr-1) Gardiners GC1 1.4 1130 Af (15), Aa (33), Gm (26), Gh (3), Pg (23) 0.08 3.6 67 GC2 1.1 530 Aa (26), Gm (71), Gh (3) 0.18 20.2 91 GC3 0.9 480 Aa (4), Ca (29), Gm (34), Gh (29), Ma (4) 0.04 0.3 24 GC4 1.2 580 Ca (6), Cc (18), Gh (75), Ma (1) 0.13 50.5 68 GC5 0.9 350 Gb (20), Gh (40), Ma (40) 0.01 0.03 5.8 Back BC1 1.0 490 Aa (37), Gm (4), Ma (59) 0.05 10.3 26 Scotchmans SC1 0.8 290 Aa (1), Gm (93), Gh (1), Ma (5) 0.25 1.4 92 SC2 0.9 170 Aa (27), Gm (40), Gh (33) 0.08 6.0 17 SC3 0.7 300 Gb (100) 0.01 0.2 6 Damper DC1 0.7 170 No fish 0 0 0 Abbreviations denote species as: Af – Acanthogobius flavimanus; Aa - Anguilla australis; Ca - Carassius auratus; Cc - Cyprinus carpio; Gb - Galaxias brevipinnis; Gm – Galaxias maculatus; Gh - Gambusia holbrooki; Pg - Philypnodon grandiceps; Ma - Misgurnus anguillicaudatus.

Department of Natural Resources and Environment – Freshwater Ecology 26 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Aquatic Fauna Community Health

The condition of aquatic fauna assemblages varied throughout the study area, ranging from degraded (GC4 and GC5) to good (SC3) (Table 3-7). The diversity of native species recorded was low at all sites (0-20% of expected species) while the relative abundance of exotic species varied (0-100% relative abundance) (Table 3-7).

In Gardiners Creek, the condition of aquatic fauna assemblages varied between sites with no apparent spatial trend. The mid-reach (GC3) and most downstream (GC1) site were both described as having poor health (Table 3-7). The diversity of native species recorded at these sites were similar, 14% and 20% of the diversity expected respectively, while the relative abundance of exotic species were quite different, 62% and 18% respectively, although both sites were still ranked as having poor health (Table 3-7). The second most downstream site (GC2) was described as having moderate health (Table 3-7). The diversity of native species recorded was 13% of the diversity expected, and the relative abundance of exotic species was 3% (Table 3-7). This classification is primarily due to the low abundance of exotic species and did not accurately reflect the low native species diversity (Table 3-7). Survey sites located in the upper reaches of Gardiners Creek (GC4 and GC5) were described as having degraded health (Table 3-7). At these sites the diversity of native species recorded ranged from 0% to 13% of the diversity expected, and the relative abundance of exotic species ranged from 80 to 100% (Table 3-7).

In Back Creek (BC1) the condition of aquatic fauna assemblages was described as poor. The diversity of native species recorded was 13% of the diversity expected, and the relative abundance of exotic species was 59% (Table 3-7). In Scotchmans Creek, the condition of aquatic fauna assemblages varied between sites with no apparent spatial trend. The most downstream site (SC1) was described as having moderate health. The diversity of native species recorded was 14% of the diversity expected, and the relative abundance of exotic species was 5% (Table 3-7). Site SC2, located in the mid reaches of Scotchmans Creek was described as having poor health (Table 3-7). The diversity of native species recorded was 15% of the diversity expected, and the relative abundance of exotic species was 33% (Table 3-7). The most upstream site (SC3) was described as having good health. The diversity of native species recorded was 14% of the diversity expected, and the relative abundance of exotic species was 0% (Table 3-7). This classification is primarily due to the absence of exotic species and again did not accurately reflect the low native species diversity (Table 3-7). In Damper Creek (DC1) the condition of aquatic fauna assemblages was described as moderate although no fish were recorded (Table 3-7).

Department of Natural Resources and Environment – Freshwater Ecology 27 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

Table 3-7. The proportion of species recorded at each site expressed as a percentage of total number of expected species and the relative abundance (%) of exotic fish at each site. The ranked score for each component is given in parentheses. Creek and Site Expected native species % of % exotic Rank and expected abundance Description GC1 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, Nc, No, Pg, Pm, Pu, Rs 20 (1) 18 (5) 6 (poor) GC2 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, Nc, No, Pg, Pm, Pu, Rs 13 (1) 3 (7) 8 (moderate) GC3 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, No, Pg, Pm, Pu, Rs 14 (1) 62 (3) 4 (poor) GC4 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, No, Pg, Pu, Rs 0 (0) 100 (0) 0 (degraded) GC5 Aa, Gb, Gm, Gt, Na, Pg, Pu, Rs 13 (1) 80 (0) 1 (degraded) Back BC1 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, Nc, No, Pg, Pm, Pu, Rs 13 (1) 59 (3) 4 (poor) Scotchmans SC1 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, No, Pg, Pm, Pu, Rs 14 (1) 5 (7) 8 (moderate) SC2 Aa, Ga, Gb, Gm, Gma, Gp, Gt, Mm, Na, No, Pg, Pu, Rs 15 (1) 33 (3) 4 (poor) SC3 Aa, Gb, Gm, Gt, Pg, Pu, Rs 14 (1) 0 (9) 10 (good) Damper DC1 Aa, Gb, Gm, Gt, Na, Pu, Pg, Rs 0 (0) 0 (9) 9 (moderate) Abbreviations denote species as: Aa - Anguilla australis; Ga - Geotria australis (Pouched lamprey); Gb - Galaxias brevipinnis; Gm - Galaxias maculatus; Gma - Gadopsis marmoratus; Gp - Galaxiella pusilla; Gt - Galaxias truttaceus (Spotted galaxias); Mm - Mordacia mordax (Short-headed lamprey); Na - Nannoperca australis; Nc -Neochanna cleaveri (Australian mudfish); No – Nannoperca obscura (Yarra pygmy perch); Pg - Philypnodon grandiceps; Pm - Prototroctes maraena (Australian grayling); Pu - Pseudaphritis urvillii; Rs - Retropinna semoni. Species in bold were those recorded at each site.

Department of Natural Resources and Environment – Freshwater Ecology 28 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

4. DISCUSSION

4.1 SPECIES DIVERSITY, DISTRIBUTION AND ABUNDANCE

The diversity of native fish species recorded in the current study was low, with a total of four native species recorded, which represents less than 30% of the native species expected to occur within the catchment. In comparison, Rolling Tributaries Surveys of the Yarra River system, Diamond Creek system and Western Port streams have recorded ten, seven and eight native fish species, representing approximately 80%, 70% and 60% of the native species expected to occur, respectively (Raadik and O’Connor 1997, Lieschke and Raadik 1999, Close et al. 2001).

Three native fish species previously recorded within the Gardiners Creek system were not recorded in the current study, namely river blackfish, dwarf galaxias and southern pygmy perch. These species have been recorded only once in the study area, river blackfish in Gardiners Creek ca. 1950 (DNRE 2002) and dwarf galaxias and southern pygmy perch in Scotchmans Creek pre-1985 (MV). These species are particularly susceptible to instream impacts owing to their limited dispersal and recolonisation ability (Koehn and O’Connor 1990). Their apparent absence in the current study suggests that viable populations may no longer occur in the study area.

The diversity of native fish species observed in the current study declined with increasing distance upstream. Although species diversity may decline as distance inland increases, owing to factors such as availability of suitable habitats and migratory ability (McDowall 1998), in the Gardiners Creek system stream accessibility has been artificially reduced by human disturbance (e.g. instream barriers and stream channelisation). The number of native fish observed in the current study was low, except for the lower reaches of Gardiners and Scotchmans creeks, where two native migratory species, namely common galaxias and short-finned eel, were generally prevalent. McDowall (1998) suggests that the effects of distance upstream will produce a parallel decline in abundance of species, however, it is difficult to distinguish between these effects and the effects of human disturbance in the study area.

The relative dominance of native and exotic fish species varied throughout the study area. In general, fish communities in Scotchmans Creek and the lower reaches of Gardiners Creek are dominated by native species, whereas in Back Creek and the middle to upper reaches of Gardiners Creek exotic species dominate fish assemblages. Native species were numerically dominant overall (66% of total abundance), whereas exotic species comprised the majority of total fish biomass (53% of total biomass) due to differences in body size and the presence of large carp in the upper reaches of Gardiners Creek.

Department of Natural Resources and Environment – Freshwater Ecology 29 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

The current aquatic fauna assemblage in the Gardiners Creek catchment is considered depauperate relative to what may be expected to occur naturally. There are numerous other native fish species that may have been expected to inhabit the Gardiners Creek system, namely, pouched lamprey (Geotria australis), spotted galaxias (Galaxias truttaceus), short-headed lamprey (Mordacia mordax), Australian grayling (Prototroctes maraena), Australian mudfish (Neochanna cleaveri) and tupong (Pseudaphritis urvillii). These species have been recorded in recent surveys of the lower Yarra River and/or tributaries (Raadik 1996, Zampatti and Lieschke 1999, Koster 2002, Zampatti and Koster unpublished data). Their apparent absence in the study area may reflect the generally degraded nature of streams in the Gardiners Creek system. Another species, namely Yarra pygmy perch (Nannoperca obscura), was recorded in the lower Yarra River system during the late 1800’s, but has not since been recorded in the Yarra Basin.

4.2 HEALTH OF AQUATIC FAUNA ASSEMBLAGES

The rationale employed in this study to assess the condition of aquatic fauna assemblages uses a biotic index incorporating two parameters of aquatic fauna population dynamics: species diversity and exotic species abundance (a measure of naturalness). Based on the data presented here for each site, the rationale has provided a reasonable assessment of health of aquatic fauna assemblages for most sites.

The results of the current study are reasonably consistent with several previous studies assessing the environmental health of streams in the Gardiners Creek system (Melbourne Water 1997, Hardwick and Waller 1999, Yarra Care 1999, Bessell-Browne 2000, Deveraux et al. 2000). Previous assessments of environmental condition in the Gardiners Creek system have generally used a range of indicators that include ecological and physicochemical parameters. Bessell-Browne (2000) assessed the environmental health of Gardiners Creek using macroinvertebrate-based rapid bioassessment and physicochemical measurement. Bessell-Browne (2000) reported that no sites in Gardiners Creek complied with WoV Schedule F7 (Government of Victoria 1999) objectives for biological indicators and that some sites failed to comply with pH, total nitrogen and total phosphorus objectives. Similarly, an assessment of the health of the Gardiners Creek system by Melbourne Water (1997) described water quality and stream condition as poor, and community health of aquatic macroinvertebrates as very poor to fair.

The results presented here for Damper Creek (DC1), the second most downstream site on Gardiners Creek (GC2), and the most upstream site on Scotchmans Creek (SC3), are however, of concern. According to the rationale, the site on Damper Creek (DC1) and Gardiners Creek (GC2) scored ‘moderate’ and the site on Scotchmans Creek (SC3) scored ‘good’. The proportion of native species recorded of the total number of native species expected to occur at these sites was low (0-14%) and therefore they scored a low naturalness ranking (DC1 – ‘degraded, GC2 and SC3 – ‘poor’). The abundance of

Department of Natural Resources and Environment – Freshwater Ecology 30 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks exotic species at these sites was very low (0-3%) and therefore they scored a high ranking for this component (DC1 and SC3 - ‘excellent’, GC2 - ‘good’). The summed ranks for these two components were ‘moderate’ for Damper Creek (DC1) and Gardiners Creek (GC2), and ‘good’ for Scotchmans Creek (SC3). In this situation of low expected native species and very low exotic abundance, undue weight is given in the summed ranking to the exotic abundance score (see also Close et al. 2001). Close et al. (2001) previously suggested that when observed/expected of native species is low (ie. <30%), the weight of the exotic abundance rank score should be reduced by half before summing. In this current assessment, this would result in a ‘poor’ rank score for these three sites, which is considered a more appropriate assessment. Nevertheless, further refinement of the ranking method is required to ensure suitability under all conditions.

4.3 IMPACTS ON AQUATIC FAUNA

Numerous factors impacting on environmental condition, and more specifically aquatic fauna assemblages, were identified within the study area. In general these disturbances relate to the entire study area. The highly urbanised nature of the Gardiners Creek system is considered a major factor impacting on aquatic fauna assemblages within the study area.

In relation to aquatic fauna assemblages within the study area several processes are identified as having some environmental impact. These include:

" Barriers to fish migration, " Introduction of exotic species, " Changes to stream channels, " Changes to water quality, " Clearing of riparian vegetation.

Barriers to fish migration

The provision of fish passage throughout stream systems is an essential component of maintaining healthy stream fish assemblages, enabling spawning migrations, general movement and habitat selection, and recolonisations. Approximately three-quarters of the native fish species recorded in the current study migrate between freshwater and estuarine/marine habitats at some stage in their life cycle (McDowall and Fulton 1996). Yarra Care (1999) identified 15 barriers to fish passage in the Gardiners Creek system, although none of these were classified as significant. In the current study, potential barriers were identified at most sites; this included culverts, concrete channels and a concrete weir. The extent to which these structures impede native fish passage in the Gardiners Creek system is unknown. One native migratory species, namely broad-finned galaxias, was recorded in the upper reaches of both Gardiners and Scotchmans creeks, although few individuals were collected. The native migratory short-finned eel has

Department of Natural Resources and Environment – Freshwater Ecology 31 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks previously been recorded in the upper reaches of the catchment (DNRE 2002), and in the current study this species, and another native migratory species, namely common galaxias, occurred as far upstream as the middle reaches, although abundances were higher at downstream sites.

Introduction of exotic species

The effects of exotic species on native fish populations may include direct predation, competition for food and habitat, the spread of disease, and habitat modification. All of the exotic species recorded in the current study have been known to occur in the Gardiners Creek system for over a decade, with the exception of one species, namely yellow-fin goby, which have not previously been collected (DNRE 2002). Yellow-fin goby were first recorded in Victoria in 1991 from the lower Yarra River and have since been collected from several other areas including the Maribyrnong, Werribee and Little rivers (DNRE 2002). Yellow-fin goby usually inhabit freshwater reaches of streams just above the tidal influence (DCNR 1993), which suggests the species may be restricted in the study area to the lower reaches of Gardiners Creek. Several exotic species previously recorded in the Gardiners Creek system, namely, redfin, roach and brown trout, were not collected in the current study. Redfin and roach were recorded in Blackburn Lake on several occasions from 1973 to 1988 and may still occur in this region. Brown trout were recorded in Gardiners Creek ca. 1950, but have not since been recorded and may no longer occur in the study area.

Changes to stream channels

Stream modification works (e.g. piping, concrete lining) have extensively altered the natural course and form of streams in the Gardiners Creek catchment (Duxbury 1990). The most obvious effect of these disturbances is a reduction in the diversity and availability of instream physical habitat components (e.g. rocks, logs and aquatic plants). Other effects may include changes to hydraulic characteristics (e.g. increased homogenous flow, rapid rise and fall of water surface levels) and creation of barriers to fish movement. These changes may impact upon fish communities in the Gardiners Creek system through a lack of spawning sites and food resources, exposure to predators, sudden reductions in water levels that may leave fish stranded, exposure to a constant flow of fast water, and the prevention of localised and large-scale movements required for habitat selection, spawning and recolonisations.

Changes to water quality

Several studies have previously identified poor water quality as impacting on the environmental condition of streams in the Gardiners Creek catchment (Melbourne Water 1997, Bessell-Browne 2000, Deveraux et al. 2000). High water temperature (34.2ºC) and pH levels (9.9) were recorded in Gardiners Creek at Warrigal Road in the current study. The levels recorded exceed known water temperature and pH preferences for the

Department of Natural Resources and Environment – Freshwater Ecology 32 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks majority of species recorded, or expected to occur, in the Gardiners creek system (Koehn and O’Connor 1990, O’Brien DNRE pers. comm.).

Clearing of riparian vegetation

An intact riparian zone is an essential component of maintaining a healthy aquatic ecosystem, acting as a buffer from surrounding land use, supplying a source of nutrients for the aquatic food chain, preventing bank erosion, and providing instream habitat and stream shading (Koehn and O’Connor 1990). The riparian zone throughout much of the study area is largely cleared of native vegetation and comprises mostly exotic grasses. An obvious effect of the degraded nature of the riparian vegetation is the lack of stream shading, which may contribute to elevated water temperatures (e.g. Gardiners Creek at Warrigal Road). The poor condition of riparian vegetation may also contribute to the limited amount of logs, branches and leaves available as instream cover.

4.4 SIGNIFICANT SPECIES

The record of dwarf galaxias in Scotchmans Creek (pre-1985) is the only documented record of this species in the Yarra Basin (DNRE 2002). Dwarf galaxias is classified as ‘vulnerable’ nationally (ANZECC 2000) and is listed as a protected species under the Environment Protection and Biodiversity Conservation Act 1999. The abundance of dwarf galaxias has declined in river systems throughout Victoria, particularly in developed areas near Melbourne (Unmack and Paras 1995). Dwarf galaxias is considered prone to threats including habitat degradation and competitive interactions with the exotic eastern gambusia (Breen et al. 1989, Koster 1997) which may result in population extinction (SAC 1991). Dwarf galaxias typically inhabit still or slow-flowing waters such as swamps, billabongs, drains and backwaters of creeks and streams, often amongst dense aquatic vegetation (Humphries 1986, Koster 1997). Although dwarf galaxias were not recorded in the current study, off-stream habitats, which were not surveyed in the current study, should be assessed for the presence of this species.

Although none of the aquatic fauna species recorded in the current study are listed as threatened taxa in Victoria (DCNR 1995, DNRE 2000), records of broad-finned galaxias in the upper reaches of the catchment should be considered regionally significant given the species rarity throughout the Port Phillip region (DNRE 2002).

Department of Natural Resources and Environment – Freshwater Ecology 33 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

4.5 RECOMMENDATIONS

The following recommendations are made regarding refinement of the Rolling Tributaries Methodology and to issues raised in the discussion.

" Identify barriers to fish movement and assess their significance.

" Investigate the potential for reducing water velocity, and providing refuge areas, in channelised stream sections.

" Enhance and maintain riparian vegetation.

" Additional aquatic fauna surveys specifically designed to establish the presence/absence of dwarf galaxias.

" Review and modification of the health assessment rationale based on naturalness and relative abundance of exotic fish species, in order for it to provide appropriate indication of stream health under circumstances such as those highlighted in this and previous studies.

Department of Natural Resources and Environment – Freshwater Ecology 34 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

5. ACKNOWLEDGMENTS

Thanks are extended to Rhys Coleman (Melbourne Water) for coordinating this project. Thanks also to Steve Saddlier and Anthony Conallin (Freshwater Ecology Section) for their assistance with fieldwork, Pete Fairbrother (Freshwater Ecology Section) for data collation, and Tarmo Raadik and Paul Close (Freshwater Ecology Section) for assistance with compiling the expected species list, and comments on the manuscript.

Department of Natural Resources and Environment – Freshwater Ecology 35 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

6. REFERENCES

Allen, G.R. (1989). Freshwater fishes of Australia. TFH Publications, New Jersey, USA.

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Anderson, J.R., Hill, J.M. and Morison, A.K. (1989). Environmental flow studies for the Wimmera River, Victoria. Part E. Technical appendices. Arthur Rylah Institute for Environmental Research, Technical Report Series No. 77. Department of Conservation, Forests and Lands, Victoria.

ANZECC (2000). List of threatened Australian vertebrate fauna. Australian and New Zealand Environment and Conservation Council, Canberra.

Bessell-Browne, T. (2000). Environmental health of streams in the Yarra River catchment. Environment Protection Authority, Melbourne.

Breen, P.F., Condina, P., Donnelly, A. and Muir, S. (1989). Pusilla Flats (Tirhatuan Wetlands). Ecology, development and management strategy. DVA, Technical Report No. 33. Dandenong Valley Authority, Melbourne.

Close, P.G. (2000). Assessment of the aquatic fauna of Kororoit Creek, Victoria. Report for Melbourne Water. Arthur Rylah Institute for Environmental Research. Department of Natural Resources and Environment, Melbourne.

Close, P. Koster, W. and Lyon, J. (2001). An assessment of the aquatic fauna in four Western Port sub-catchments (Victoria): Cardinia, Gum Scrub, Toomuc and Deep creeks. Report for Melbourne Water. Arthur Rylah Institute for Environmental Research. Department of Natural Resources and Environment, Melbourne.

Deveraux, A. Tiller, D. and Metzeling, L. (2000). An environmental study of Blackburn Lake. Environment Protection Authority, Melbourne.

DCNR (1993). Victorian Fisheries Notes. 107. Department of Conservation and Natural Resources, Melbourne.

DCNR (1995). Threatened fauna in Victoria - 1995. Department of Conservation and Natural Resources, Melbourne.

DNRE (2000). Threatened vertebrate fauna in Victoria – 2000. Department of Natural Resources and Environment, Melbourne.

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DNRE (2002). Victorian Aquatic Fauna Database. Department of Natural Resources ad Environment, Melbourne.

Duxbury, K. (1990). Wetlands at Malvern: a municipal experience. In: Wetlands: their ecology, function, restoration and management: Applied Ecology and Conservation Seminar, Oct-Dec 1989, La Trobe University, Bundoora.

Gordon, N.D. McMahon, T.A. and Finlayson, B.L. (1992). Stream hydrology: An introduction for ecologists. John Wiley & Sons, West Sussex, England.

Hardwick, R. and Waller, K. (1999). Melbourne Water macroinvertebrate monitoring program. Water Ecoscience, Melbourne.

Horwitz, P. (1990). A taxonomic revision of species in the freshwater crayfish genus Engaeus Erichson (Decapoda: Parastacidae). Invertebrate Taxonomy 4: 427-614.

Humphries, P. (1986). Observations on the ecology of Galaxiella pusilla (Mack) (Salmoniformes: Galaxiidae) in Diamond Creek, Victoria. Proceedings of the Royal Society of Victoria. 98: 133-137.

Jerry, D.R., Elphinstone, M.S. and Baverstock, P.R. (2001). Phylogenetic relationships of Australian members of the family Percichthyidae inferred from mitochondrial 12S rRNA sequence data. Molecular Phylogenetics and Evolution 18(3): 335-347).

Koehn, J. D. and O’Connor, W. G. (1990). Biological information for the management of native freshwater fish in Victoria. Government Printer, Melbourne.

Koster, W.M. (1997). A study of the interactions between the Dwarf Galaxias, Southern Pygmy Perch and Eastern Gambusia. B.Sc (Hons) Thesis. Deakin University, Melbourne.

Koster, W. M. (2002). Ecological impact of removing effluent flows from Craigieburn Sewage Treatment Plant on Merri Creek: assessment of fish and decapod crustacea. Report to Egis Consulting. Freshwater Ecology, Department of Natural Resources and Environment, Melbourne.

Lieschke, J. and Raadik, T.A. (1999). An assessment of the aquatic biota at selected sites in the Diamond Creek system. Report to Melbourne Water. Freshwater Ecology, Parks Flora and Fauna, Department of Natural Resources and Environment, Victoria.

McDowall, R.M. (1997). Affinities, generic classification and biogeography of the Australian mudfishes (Salmoniformes: Galaxiidae). Records of the Australian Museum. 49(2): 121-137.

Department of Natural Resources and Environment – Freshwater Ecology 37 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

McDowall, R. M. (1998). Fighting the flow: downstream-upstream linkages in the ecology of diadromous fish fauna in West Coast New Zealand rivers. Freshwater Biology. 40: 111-122.

McDowall, R.M. and Fulton, W. (1996). Family Galaxiidae. In: McDowall, R.M. (Ed). Freshwater fishes of south-eastern Australia. Reed Books, Australia. pp198-199.

Melbourne Water (1997). Health of Waterways Within the Port Phillip & Western Port Catchments: Annual Stream Health Monitoring Report, 1997. Eds. Coleman, R., Batty, M., Pettigrove, V. Melbourne Water Corporation, Melbourne.

MV. Fish collection records. Museum of Victoria.

Paxton, J. R., Hoese, D. F., Allen, G. R. and Hanley, J. R. (1989). Zoological catalogue of Australia. Volume 7. Pisces. Petromyzontidae to Carangidae. Australian Government Publishing Service, Canberra.

Piha, H. (1992). Dights Falls development study. City of Collingwood.

Poussard, H. (1996). Draft Yarra catchment strategy. Department of Natural Resources and Environment, Melbourne.

Raadik, T. A. (1996). Initial assessment of the movement at moderate flows levels of fish through the Dights Falls fishway, Yarra River, Melbourne. Marine and Freshwater Resources Institute, Melbourne.

Raadik, T.A. and O'Connor, J. P. (1997). Fish survey of selected sites in the Yarra River and Dandenong Creek systems, Rolling Tributaries Program. Consultancy Report to Melbourne Water. Marine and Freshwater Resources Institute, Melbourne.

Raadik, T.A. and Zampatti, B. (1998). An assessment of the aquatic biota at selected sites in the Lang Lang River system and south-east Mornington Peninsula, Rolling Tributaries Program. Consultancy Report to Melbourne Water. Marine and Freshwater Resources Institute, Melbourne.

Raadik, T.A. and Lieschke, J. A. (1999). An assessment of the aquatic biota at selected sites in the Plenty River system. Consultancy Report to Melbourne Water. Arthur Rylah Institute for Environmental Research, Melbourne.

Raadik, T.A., Zampatti, B. and Lieschke, J. (1999). An assessment of aquatic biota at selected sites in the Woori Yallock Creek system. Report to Melbourne Water. Freshwater Ecology, Parks Flora and Fauna, Department of Natural Resources and Environment, Melbourne.

Riek, E. F. (1969). The Australian freshwater crayfish (Crustacea: Decapoda: Parastacidae), with descriptions of new species. Australian Journal of Zoology. 17: 855-918.

Department of Natural Resources and Environment – Freshwater Ecology 38 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

SAC (Scientific Advisory Committee) (1991). Final recommendation on a nomination for listing: Galaxiella pusilla (Mack, 1936) - Dwarf Galaxias. Nomination No. 141. Department of Natural Resources and Environment, Melbourne.

Unmack, P.J. and Paras, G.J. (1995). Galaxiella pusilla: around Melbourne, going, going, nearly gone. Fishes of Sahul 9(1), 398-400

Williams, W.D. and Smith, M.J. (1979). A taxonomic revision of Australian species of Paratya (Crustacea: Atyidae). Australian Journal of Marine and Freshwater Research 30: 815 - 832.

Yarra Care (1999). Overview of the status of waterways in the Yarra catchment. Yarra Catchment Implementation Committee, Melbourne.

Zampatti, B. and Lieschke, J. (1999). An assessment of environmental flow requirements for the Diamond Creek catchment. Report to Melbourne Water. Department of Natural Resources and Environment, Melbourne.

Department of Natural Resources and Environment – Freshwater Ecology 39 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7. APPENDIX A

7.1 GARDINERS CREEK – GC1

SITE DETAILS Stream name: Gardiners Creek Location: Downstream of concrete channel, Glenferrie Road, Hawthorn Map: 7922 Zone: 55 AMG: 326300-5810200 Date sampled: 1/2/02 Altitude: 20 m.a.s.l. Instantaneous discharge: 4.0 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 11.3 m Average depth 0.4 m Reach Area: 1130 m-2 Total time: 84 min Run 1: 44 min Run 2: 40min PHYSICO-CHEMICAL DATA Conductivity: 273.0 µS.cm-1 Temperature: 19.7°C DO: 4.6 mg.L-1 pH: 7.1 Turbidity: 8.8 NTU Time: 0900 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range Acanthogobius flavimanus 14 0 14 64 52-127 2.6 1.1-15.4 Anguilla australis 19 12 31 371 69-830 251 1.3-1460 Galaxias maculatus 11 13 24 63 48-80 1.6 0.7-3.1 Gambusia holbrooki 1 2 3 24 21-28 0.1 0.1-0.2 Philypnodon grandiceps 9 13 22 68 51-95 2.6 1.1-4.9 FAUNA CHARACTERISTICS Total no. fish: 94 Fish species: 5 Fish density: 0.08 fish.m-2 Total fish biomass: 3.6 g.m-2 CPUE: 67 fish.hr-1 Native: exotic ratio 3:2 Relative abundance of exotic species: 18%

Department of Natural Resources and Environment – Freshwater Ecology 40 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.2 GARDINERS CREEK – GC2

SITE DETAILS Stream name: Gardiners Creek Location: Downstream of Tooronga Road, Malvern Map: 7922 Zone: 55 AMG: 327600-5809200 Date sampled: 25/1/02 Altitude: 20 m.a.s.l. Instantaneous discharge: 4.1 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 5.3 m Average depth 0.3 m Reach Area: 530 m-2 Total time: 64 min Run 1: 36 min Run 2: 28 min PHYSICO-CHEMICAL DATA Conductivity: 70.7 µS.cm-1 Temperature: 19.0 °C DO: 6.4 mg.L-1 pH: 6.8 Turbidity: 6.2 NTU Time: 0900 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range Anguilla australis 19 6 25 517 41-775 465 7-1180 Cherax destructor 0 1 1 - 26 - 5.0 Galaxias maculatus 32 37 69 63 45-122 1.7 0.3-11.3 Gambusia holbrooki 1 2 3 23 21-28 0.1 0.1-0.2 FAUNA CHARACTERISTICS Total no. fish: 97 Fish species: 3 Fish density: 0.18 fish.m-2 Total fish biomass: 20.2 g.m-2 CPUE: 91 fish.hr-1 Native: exotic ratio 2:1 Relative abundance of exotic species: 3%

Department of Natural Resources and Environment – Freshwater Ecology 41 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.3 GARDINERS CREEK – GC3

SITE DETAILS Stream name: Gardiners Creek Location: Downstream of Warrigal Road Map: 7922 Zone: 55 AMG: 332000-5806500 Date sampled: 25/1/02 Altitude: 40 m.a.s.l. Instantaneous discharge: 5.4 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 4.8 m Average depth 0.2 m Reach Area: 480 m-2 Total time: 52 min Run 1: 29 min Run 2: 23 min PHYSICO-CHEMICAL DATA Conductivity: 148.6 µS.cm-1 Temperature: 34.2°C DO: 9.7mg.L-1 pH: 9.9 Turbidity: 4.4 NTU Time: 1230 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range Anguilla australis 1 0 1 - 384 - 101 Carassius auratus 2 4 6 38 32-55 0.8 0.1-2.4 Cherax destructor 42 19 61 21 7-37 7.1 0.1-22.6 Galaxias maculatus 4 3 7 69 50-118 2.5 0.9-8.8 Gambusia holbrooki 3 3 6 19 17-22 0.1 0.1-0.2 Misgurnus anguillicaudatus 1 0 1 - 128 - 12.6 Paratya australiensis ✔ ✔ - - - - - FAUNA CHARACTERISTICS Total no. fish: 21 Fish species: 5 Fish density: 0.04 fish.m-2 Total fish biomass: 0.3 g.m-2 CPUE: 24 fish.hr-1 Native: exotic ratio 2:3 Relative abundance of exotic species: 62% ✔- Present.

Department of Natural Resources and Environment – Freshwater Ecology 42 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.4 GARDINERS CREEK – GC4

SITE DETAILS Stream name: Gardiners Creek Location: Downstream of Station Street, Burwood Map: 7922 Zone: 55 AMG: 334500-5809900 Date sampled: 29/1/02 Altitude: 60 m.a.s.l. Instantaneous discharge: 5.2 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 5.8 m Average depth 1 m Reach Area: 580 m-2 Total time: 69 min Run 1: 40 min Run 2: 29 min PHYSICO-CHEMICAL DATA Conductivity: 50.1 µS.cm-1 Temperature: 20.1 °C DO: 4.8 mg.L-1 pH: 6.9 Turbidity: 17.7 NTU Time: 0900 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run Run total Mean Range Mean Range 1 2 Carassius auratus 1 4 5 39 16-105 0.6 0.1-2.5 Cherax destructor 4 3 7 24 15-31 9.2 2.4-18.2 Cyprinus carpio 10 4 14 481 410-560 2433 1715-3329 Gambusia holbrooki 34 25 59 28 17-53 1.2 0.1-2.1 Misgurnus anguillicaudatus 1 0 1 - 54 - 1.3 FAUNA CHARACTERISTICS Total no. fish: 79 Fish species: 4 Fish density: 0.13 fish.m-2 Total fish biomass: 50.5 g.m-2 CPUE: 68 fish.hr-1 Native: exotic ratio 0:4 Relative abundance of exotic species: 100%

Department of Natural Resources and Environment – Freshwater Ecology 43 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.5 GARDINERS CREEK – GC5

SITE DETAILS Stream name: Gardiners Creek Location: Upstream of Middleborough Road, Blackburn Map: 7922 Zone: 55 AMG: 335800-5811700 Date sampled: 29/1/02 Altitude: 80 m.a.s.l. Instantaneous discharge: 2.1 M/d Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 3.5 m Average depth 0.4 m Reach Area: 350 m-2 Total time: 52 min Run 1: 28 min Run 2: 24 min PHYSICO-CHEMICAL DATA Conductivity: 50.1 µS.cm-1 Temperature: 20.5°C DO: 6.9 mg.L-1 pH: 6.9 Turbidity: 15.6 NTU Time: 1300 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range Cherax destructor 18 20 38 21 8-47 23 13.1-34.1 Galaxias brevipinnis 0 1 1 - 67 - 2.9 Gambusia holbrooki 1 1 2 27 16-38 0.4 0.1-0.7 Misgurnus anguillicaudatus 1 1 2 84 57-111 4.0 1.4-6.7 FAUNA CHARACTERISTICS Total no. fish: 5 Fish species: 3 Fish density: 0.01 fish.m-2 Total fish biomass: 0.03 g.m-2 CPUE: 5.8 fish.hr-1 Native: exotic ratio 1:2 Relative abundance of exotic species: 80%

Department of Natural Resources and Environment – Freshwater Ecology 44 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.6 BACK CREEK – BC1

SITE DETAILS Stream name: Back Creek Location: Downstream of Dawson Drive, Glen Iris Map: 7922 Zone: 55 AMG: 329300-5808400 Date sampled: 1/2/02 Altitude: 20 m.a.s.l. Instantaneous discharge: 0 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 4.9 m Average depth 0.5 m Reach Area: 490 m-2 Total time: 62 min Run 1: 35 min Run 2: 27 min PHYSICO-CHEMICAL DATA Conductivity: 235.0 µS.cm-1 Temperature: 20.3°C DO: 2.6 mg.L-1 pH: 7.1 Turbidity: 9.6 NTU Time: 1330 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run Run total Mean Range Mean Range 1 2 Anguilla australis 4 6 10 601 345-790 684 84.4-1460 Galaxias maculatus 1 0 1 - 80 - 3.1 Misgurnus anguillicaudatus 8 8 16 153 131-182 23 13.1-34.7 FAUNA CHARACTERISTICS Total no. fish: 27 Fish species: 3 Fish density: 0.05 fish.m-2 Total fish biomass: 10.3 g.m-2 CPUE: 26 fish.hr-1 Native: exotic ratio 2:1 Relative abundance of exotic species: 59%

Department of Natural Resources and Environment – Freshwater Ecology 45 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.7 SCOTCHMANS CREEK – SC1

SITE DETAILS Stream name: Scotchmans Creek Location: Footbridge at Malvern Valley Golf Course, East Malvern Map: 7922 Zone: 55 AMG: 330800-5806100 Date sampled: 30/1/02 Altitude: 40 m.a.s.l. Instantaneous discharge: 0.8 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 2.9 m Average depth 0.3 m Reach Area: 290 m-2 Total time: 48 min Run 1: 30 min Run 2: 18 min PHYSICO-CHEMICAL DATA Conductivity: 182.1 µS.cm-1 Temperature: 20.5°C DO: 7.9 mg.L-1 pH: 7.2 Turbidity: 3.3 NTU Time: 1300 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run Run total Mean Range Mean Range 1 2 Anguilla australis 1 0 1 - 363 - 93.7 Cherax destructor 3 5 8 25 23-29 10.1 7.7-14.3 Galaxias maculatus 47 22 69 78 51-163 5.4 0.5-29.7 Gambusia holbrooki 1 0 1 - 25 - 0.2 Misgurnus anguillicaudatus 1 2 3 151 151-152 21 20.8-22.4 FAUNA CHARACTERISTICS Total no. fish: 74 Fish species: 4 Fish density: 0.25 fish.m-2 Total fish biomass: 1.4 g.m-2 CPUE: 92 fish.hr-1 Native: exotic ratio 2:2 Relative abundance of exotic species: 5%

Department of Natural Resources and Environment – Freshwater Ecology 46 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.8 SCOTCHMANS CREEK – SC2

SITE DETAILS Stream name: Scotchmans Creek Location: Downstream of Huntingdale Road Map: 7922 Zone: 55 AMG: 333400-5804500 Date sampled: 30/1/02 Altitude: 60 m.a.s.l. Instantaneous discharge: 1 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 1.7 m Average depth 0.3 m Reach Area: 170 m-2 Total time: 53 min Run 1: 29 min Run 2: 24 min PHYSICO-CHEMICAL DATA Conductivity: 127.7µS.cm-1 Temperature: 18.9°C DO: 2.9 mg.L-1 pH: 6.9 Turbidity: 3.1 NTU Time: 0900 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run Run total Mean Range Mean Range 1 2 Anguilla australis 3 1 4 433 215-670 244 18-649 Galaxias maculatus 4 2 6 74 51-152 5 0.7-27.5 Gambusia holbrooki 2 3 5 31 12-55 0.9 0.2- 2.7 FAUNA CHARACTERISTICS Total no. fish: 15 Fish species: 3 Fish density: 0.08 fish.m-2 Total fish biomass: 6 g.m-2 CPUE: 17 fish.hr-1 Native: exotic ratio 2:1 Relative abundance of exotic species: 33%

Department of Natural Resources and Environment – Freshwater Ecology 47 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.9 SCOTCHMANS CREEK – SC3

SITE DETAILS Stream name: Scotchmans Creek Location: Upstream of Regent Street, Mount Waverley Map: 7922 Zone: 55 AMG: 336100-5805100 Date sampled: 31/1/02 Altitude: 80 m.a.s.l. Instantaneous discharge: 0.7 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 3 m Average depth 0.3 m Reach Area: 300 m-2 Total time: 39 min Run 1: 22 min Run 2: 17 min PHYSICO-CHEMICAL DATA Conductivity: 107.8µS.cm-1 Temperature: 18.7°C DO: 3.3mg.L-1 pH: 7.1 Turbidity: 8.4 NTU Time: 0900 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range Galaxias brevipinnis 2 2 4 109 72-147 15 3.3-30.8 FAUNA CHARACTERISTICS Total no. fish: 4 Fish species: 1 Fish density: 0.01 fish.m-2 Total fish biomass: 0.2 g.m-2 CPUE: 6 fish.hr-1 Native: exotic ratio 1:0 Relative abundance of exotic species: 0%

Department of Natural Resources and Environment – Freshwater Ecology 48 An Assessment of Aquatic Fauna in Gardiners, Scotchmans, Back and Damper Creeks

7.10 DAMPER CREEK – DC1

SITE DETAILS Stream name: Damper Creek Location: Upstream of Park Road, Mount Waverley Map: 7922 Zone: 55 AMG: 334900-5807100 Date sampled: 31/1/02 Altitude: 80 m.a.s.l. Instantaneous discharge: 0 ML.d-1 Gauge height: - SAMPLE DETAILS Sample length: 100 m Average width: 1.7 m Average depth 0.1 m Reach Area: 170 m-2 Total time: 40 min Run 1: 23 min Run 2: 17 min PHYSICO-CHEMICAL DATA Conductivity: 51.1 µS.cm-1 Temperature: 19.4°C DO: 3 mg.L-1 pH: 6.8 Turbidity: 3.4 NTU Time: 1200 hrs COLLECTION DATA Abundance Length (mm) Weight (g) Species Run 1 Run 2 total Mean Range Mean Range No fish 0 0 0 - - - - FAUNA CHARACTERISTICS Total no. fish: 0 Fish species: 0 Fish density: 0 fish.m-2 Total fish biomass: 0 g.m-2 CPUE: 0 fish.hr-1 Native: exotic ratio - Relative abundance of exotic species: 0%

Department of Natural Resources and Environment – Freshwater Ecology 49