Movement and habitat preference of in Lake Eildon

John Douglas

April 2009

Fisheries Victoria Research Report Series No. 38

Golden perch movement and habitat

If you would like to receive this Author Contact Details: John Douglas information/publication in an Fisheries Research Branch, Fisheries Victoria accessible format (such as large Private Bag 20, Alexandra Victoria 3714 print or audio) please call the Authorised by the Victorian Government, Customer Service Centre on: 1 Spring Street, Melbourne 136 186, TTY: 1800 122 969, Printed by DPI Snobs Creek, Victoria or email Published by the Department of Primary [email protected] Industries. © The State of Victoria, Department of Primary Copies are available from the website: Industries, 2009. www.dpi.vic.gov.au/fishing This publication is copyright. No part may be General disclaimer reproduced by any process except in accordance This publication may be of assistance to you but with the provisions of the Copyright Act 1968. the State of Victoria and its employees do not Preferred way to cite this publication: guarantee that the publication is without flaw of any kind or is wholly appropriate for your Douglas J.W. (2009) Movement and habitat particular purposes and therefore disclaims all preferences of golden perch in Lake Eildon. liability for any error, loss or other consequence Fisheries Victoria Research Report Series No. 38. which may arise from you relying on any ISSN 1448‐7373 information in this publication. ISBN 978‐1‐74217‐482‐2

Golden perch movement and habitat ii Executive Summary

Golden perch were tracked in Lake Eildon to investigate movement and habitat preference, They were found to have home ranges (site affinity) with a certain area and that this area is relatively larger in impoundments than in streams. The display homing behaviour in that they have the ability to return to their home range after being moved to another location. There is no strong association of golden perch with any particular type of habitat in Lake Eildon. The fish do seem to display some trends in preferring different areas of the lake at different times of the year. Golden perch show a trend in seasonal movement pattern that see them come closer to the shore in spring and early summer as the water temperature increases. They tend to move offshore in mid to late summer. Some golden perch are near the banks all year. The fish are equally as active in winter as in summer. Anglers wishing to target golden perch in the spring to early summer should fish near the banks when the fish appear to be closer to the shore. The presence of trees or steep banks does not appear to be needed. Anglers may have to try several areas before finding fish including banks with no trees or other obvious structure. Anglers wishing to target golden perch in the late summer should possibly try the heads of standing dead trees and fish in the upper 10 metres of the water column and above the thermocline if it can be detected. A winter fishery in Lake Eildon for golden perch may be an option.

Golden perch movement and habitat iii Table of Contents

Executive Summary...... iii

Table of Contents ...... iv

Introduction...... 1

Project Design and Methods ...... 2 Study rationale ...... 2 Study site...... 2 Telemetry tagging of golden perch ...... 3 Locating golden perch...... 3 Large scale movement and testing for spatial randomness ...... 3 Activity and depth ...... 3

Results...... 5 Spatial distribution ...... 5 Site fidelity...... 5 Homing...... 6 Golden perch preferred habitat associations...... 6 Lake shore...... 7 Standing dead trees ...... 8 Water temperature...... 8 Golden perch activity and depth ...... 9 Diurnal activity ...... 9 Seasonal activity ...... 9 Depth...... 9 Modelling golden perch depth...... 10

Discussion...... 11 Spatial distribution and movement of golden perch in lakes and rivers...... 11 Movement and angling...... 11 Movement hypothesis...... 12 Diel movement...... 12

Conclusions ...... 13

References ...... 14

Appendix 1‐ Individual golden perch locations for 2002‐03 tracking ...... 16

Acknowledgements...... 19

Golden perch movement and habitat iv

List of Tables Table 1. Details of golden perch implanted with acoustic tags in Lake Eildon ...... 5 Table 2. Details of golden perch implanted with radio tags and used in activity and depth investigations 9

List of Figures Figure 1. Diagram of Lake Eildon highlighting location of study area. Detail of study area (box) presented in Figure 2...... 2 Figure 2. Detail of study area showing golden perch locations for whole of study, high water mark at full supply as blue line, and satellite image of representative lake height at time of study. Coloured dots represent separate fish...... 6 Figure 3. Monthly mean of stratification index. Higher values indicate larger temperature difference (stratification) between surface and deeper water. Negative values indicate surface water is colder than deeper water, positive values indicate surface water is warmer than deeper water...... 7 Figure 4. Comparison of monthly stratification index and mean monthly depth of lake at golden perch locations...... 7 Figure 5. Percentage of golden perch located at various distances from bank (2002‐03 data)...... 7 Figure 6. Mean distances from bank for golden perch locations by month (2002‐03 data). Error bars are standard error...... 7 Figure 7. Distance from shore for all dates for all golden perch located during the study...... 8 Figure 8. Percentage of golden perch located at various distances from standing timber (2002‐03 data). ... 8 Figure 10. Mean distances from standing timber for golden perch locations by month (2002‐03 data). Error bars are standard error...... 8 Figure 11. Comparison of stratification index and mean monthly distance to standing dead trees. Stratification index is in degrees Celsius and distance to trees is in metres...... 8 Figure 12. Water temperature compared to golden perch distance to bank, depth of the lake at the fish and golden perch distance to standing trees in Lake Eildon in 2002‐03. Error bars are standard error.9 Figure 13. Percentage distribution of golden perch observations from lake‐bed...... 10 Figure 14. Regression of distance of golden perch from lake bed with lake depth (R2 = 0.66596)...... 10 Figure 15 Golden perch ʺTag 2ʺ locations for whole study...... 16 Figure 16 Golden perch ʺTag 4ʺ locations for whole study...... 16 Figure 17 Golden perch ʺTag 5ʺ locations for whole study. Lines indicate movement direction of fish. Fish released in study area (small square) but moved to other end of lake...... 17 Figure 18 Golden perch ʺTag 6ʺ locations for whole study...... 17 Figure 19 Golden perch ʺTag 9ʺ locations for whole study...... 18 Figure 20 Golden perch ʺTag 10ʺ locations for whole study...... 18

Golden perch movement and habitat v

Introduction

Large impoundments represent major observations on habitat as determined by the recreational assets, particularly for boating and accepted golden perch angling methods and fishing. In recognition of this, many from research captures of golden perch. Angling impoundments are regularly stocked with fish for golden perch is often based on fishing to either develop or maintain recreational structure such as standing timber, rock walls fisheries. In Victoria, golden perch are one such and weed beds (Sissons 1999, Harmon 2003). species that is regularly stocked into selected Many golden perch have been caught in Lake impoundments across the state. Fisheries Eildon in research mesh nets set on shallow, Victoria stocked over 600 000 golden perch in grassy flats away from cover (Pers. Com. Kylie the 2003‐04 season (source: Fisheries Victoria). If Hall DPI, Snobs Creek). successful, such stockings can add much to the A better understanding of habitat preferences value of the state’s recreational fishery as well as and movement patterns of golden perch in bring commercial and service benefits to local impoundments would provide fisheries towns. The stocking of fish does not necessarily managers specific information on the habitat use create a recreational fishery. Many factors such of the species to inform advocacy for habitat as initial survival of fingerlings, related issues, or assist in future habitat competition/predation pressures with existing enhancement activities. fish species, and incompatible habitat, can all affect the outcome of stockings. Even if the The first aim of the present study was to initial survival and growth of the stocked fish is determine any broad habitat movements of the confirmed, the true value of the fishery is golden perch and determine whether there was determined by the return to the angler of fish. any relationship between golden perch distribution and specific habitat or Knowledge of the behaviour of fish in these environmental conditions. The second aim of impoundments would not only assist managers the project was to investigate small‐scale but would also provide assistance to movement /activity of golden perch especially to recreational fishers who may be able to use the investigate any behavioural change in diurnal or information to target particular recreational fish seasonal activity. species more effectively. A subsequent aim was to use some physical Netting surveys of Lake Eildon have indicated parameters that are available to anglers to that it supports a population of golden perch model golden perch depth. If this aim was with sizes considered acceptable to anglers. successful then anglers could use readily Captures of golden perch from the Lake are accessible equipment such as thermometers and relatively common, but not consistent. Anglers depth sounders to help find golden perch may benefit from more information on the locations. habitat preferences and movement patterns of the golden perch in the storage to target the fish more effectively. Little information is available on golden perch movement in lakes. Reynolds (1983) showed that golden perch can be quite mobile at times in river systems and Crook et al. (2001) studied golden perch habitat and movement at a smaller scale in the Broken River using telemetry. Some studies have investigated golden perch populations in lakes (Robinson 1982, Battaglene 1991, Brown 1998, Hall and Brown 2002, Brown and Hall 2003). These studies have not focussed on behaviour and habitat preference. Much of the current information available is anecdotal and is derived from the recreational fishing sector. Complicating this issue are conflicting

Golden perch movement and habitat 1 Project Design and Methods

Study rationale Victoria’s north east and at full supply the Lake has a shoreline of 483 km, an area of 13,840 ha, a The study had two parts. capacity of 3,390,000 ML and a maximum depth 1. The investigation of general movement and of 76 m (source: Goulburn Murray Water). Fish habitat associations of golden perch species present in the lake include redfin (Perca fluvilatius), goldfish (Carassius auratus), roach 2. Investigating the depth preference and (Rutilus rutilus), carp (Cyprinus carpio), Australian diurnal movement of the fish. smelt (Retropinna semoni), mountain galaxias (Galaxias olidus), brown trout (Salmo trutta), The different aspects of the research used rainbow trout (Onchorynchus mykiss), golden different tags. The general movement and habitat perch ( ambigua), associations used acoustic tags. These tags ( peelii peelii) and require a hydrophone to locate them. The second (Macquarie australasica) (Tunbridge and Rogan aspect of the work used radio tags. These tags 1991). used a radio receiver and aerial for location. Radio telemetry was used for depth work The study primarily focussed on the Delatite arm because these tags had the capability to transmit of the lake (Figure 1). depth information.

Study site Lake Eildon is one of Victoria’s largest lakes. The Lake impounds the Goulburn River at Eildon in

Figure 1. Diagram of Lake Eildon highlighting location of study area. Detail of study area (box) presented in Figure 2.

Golden perch movement and habitat 2 Telemetry tagging of golden perch Temperature and DO readings were taken below the surface (0.5 m) and at the lake bottom. An Eight golden perch were collected for acoustic index of stratification was developed from the tracking and 10 for radio tracking. The fish for difference between surface and bottom water the acoustic tracking were mainly captured by temperature (Dedual 2000). This index was used mesh netting but electrofishing (boat based, to investigate the influence of water temperature Smithroot 7.5 GPS) was also undertaken along on golden perch movement. the lake margins. Recreational anglers captured all of the 10 fish for radio tracking. At each contact with tagged fish, a suite of other physical parameters was also measured After capture, golden perch were anaesthetised including position of fish, lake depth at the with Benzocaine (ethyl p‐aminobenzoate). The location of the fish, the presence of structure implanting method followed that of Ross and (such as large woody material), the distance to Kleiner (1982). The acoustic pingers (Lotek nearest obvious cover and the distance to shore. CAFT) were implanted surgically via a 2.5 cm Water depth was measured in metres via a boat‐ incision on the ventral side of the fish and the mounted depth sounder (Hummingbird, 200 pinger was inserted into the abdominal cavity. DX). The presence of underwater structure was The incision was then closed with sutures and investigated by driving the boat in a grid pattern sealed with a cyanoacrylate based adhesive. In around the fish position and monitoring the radio tagged fish, the antennae was fed down a depth sounder. The distance to shore and nearest large gauge needle inserted through the cover was measured to the nearest metre with an abdominal cavity posterior to pelvic fins. Total electronic range finder (Bushnell Tour Pro XL). surgery time averaged two to three minutes. While surgery was in progress fish were kept The presence of structure, the distance to the moist with constant spraying of water over the nearest obvious cover (primarily standing dead gills and body with an atomiser. After surgery, timber) and the distance to shore parameters anaesthetised fish were allowed to recover prior were measured at a series of randomly generated to release at their capture site. The golden perch locations throughout the study area. These data were not examined to determine sex therefore no were compared to the actual data collected from differentiation is made between sexes. fish locations using multi variate analysis (Primer). Analysis of similarity (ANOSIM) was Preliminary trials had shown that golden perch used to test if the locations of fish were recovered and began eating within one week and significantly different to random locations. were fully recovered (only small evidence of scar) from the tagging operation within one Large scale movement and testing month at 20°C. for spatial randomness Locating golden perch Individual golden perch locations were subjected to site fidelity testing. Site fidelity was This component of the study tracked the acoustic investigated by the Movement extension tag implanted golden perch. The fish were for Arcview© (Hooge and Eichenlaub 1997). This located with a directional hydrophone connected extension uses a Monte Carlo simulation to to a receiver (Lotek‐SRX 400). Signal strength and investigate if the observed movement pattern has direction determined the general location of more site fidelity than should occur randomly individual fish, and a more precise location of the (Hooge and Eichenlaub 1997). fish was established when the boat was manoeuvred so that there was no change in Activity and depth signal strength for any direction, thus indicating the hydrophone was above the fish (Wilkerson Radio tagged fish were used for this component and Fisher 1997). Individual fish were recognised of the study. The fish were initially located with a from the uniquely coded acoustic tags. A GPS hand held antenna attached to a radio receiver (Magellan‐Meridian Gold) reading was taken to (ATS) while the boat was underway. Once record the location. detected, the fish location was determined in a similar way to the acoustic tags and hydrophone The golden perch were tracked regularly (at least technique. once per month) from March 2001 to March 2003. The diurnal activity experiments were Water temperature and dissolved oxygen (DO) undertaken in 2003. The golden perch were content profiles were taken at each fish location. monitored for two weeks in late summer

Golden perch movement and habitat 3 (February‐March) and in another two weeks in The radio tags implanted in the golden perch winter (June‐July). This was to investigate if there activity experiment were equipped with pressure was any difference in activity between day and sensors that transmitted depth information. With night and if there was any difference in activity each fish contact the depth of the fish, water between winter and summer. Fish were initially temperature at the surface, water temperature at located then their position was determined at the depth of the fish and the bottom of the lake least another four times with a minimum 30 where the fish was located were recorded. minutes between contacts. The distance travelled Similar measurements were also undertaken for by the fish was divided by the time between dissolved oxygen. Fish depths were compared contacts to calculate a minimum swimming with single factor ANOVA to investigate any speed in metres per minute. A single factor differences in depth on a day/night basis or ANOVA was used to compare swimming speeds seasonally. and determine if any significant differences in Linear regression analysis (stepwise regression) activity between night and day were present. The was used to investigate and describe the depth of tests were also conducted on seasonal data to the fish as a function of surface temperature and determine any difference in movement between other environmental factors measurable by summer and winter. recreational anglers.

Golden perch movement and habitat 4 Results

Spatial distribution regularly monitored from March 2002. Fish with tag number five was implanted with a Details of the nine golden perch implanted with transmitter in September 2002 and monitored acoustic tags are presented in Table 1. Of these thereafter. fish, five (tag numbers 9, 10, 6, 4, and 1) were

Table 1. Details of golden perch implanted with acoustic tags in Lake Eildon

Capture/release Release Length Weight Tag No Last date No of location date located contacts

Delatite Arm 5/3/2002 495 2715 9 23/4/03 39

Delatite Arm 5/3/2002 478 2163 10 11/11/02 18

Delatite Arm 5/3/2002 520 3189 7 5/3/2002 0

Delatite Arm 2/4/2002 420 1306 4 18/3/03 36

Delatite Arm 2/4/2002 390 1013 6 24/2/03 12

Delatite Arm 2/4/2002 381 928 3 9/4/02 2

Delatite Arm 2/4/2002 404 1160 2 18/12/02 39

Delatite Arm 2/4/2002 375 932 1 18/12/02 1

Goughs Bay/Delatite 11/9/2002 383 871 5 11/11/04 10

Fish were most frequently found in the Delatite arm of the lake where they were originally Site fidelity captured and released (Figure 2). Details of all The site fidelity test results were found to be golden perch tracking records are presented in highly dependent on the scale over which the Appendix 1. Of the eight Delatite fish tagged, analysis was conducted. If the tests were five fish were located 12 or more times. The performed on a whole‐of‐lake scale then the remaining three fish were only located twice or golden perch distributions were found not to be less. The highest number of contacts with an random indicating site fidelity. If the movement individual fish was 39 (Tag 9). Tag 2 was also was tested in the Delatite arm only, then the located 39 times but this fish was presumed results varied with some fish displaying site dead, as the position of the signal did not change fidelity and some fish showing random over the study. The precision in locating the movement. As the golden perch tended to stay golden perch was estimated as within 30 metres, in the Delatite arm, it was concluded that on a which was adequate given the large size of the whole‐of‐lake basis, the perch showed behaviour lake. In general, the golden perch were found to patterns that were consistent with site fidelity. As stay in the Delatite arm of the lake, while some the scale of this behaviour was quite large, a fish (Tags 9, 10 and 6) made brief excursions into more general term is required and site affinity is the main arm, they returned back into the suggested as more appropriate than site fidelity. Delatite arm area.

Golden perch movement and habitat 5 Homing and moved several kilometres into the Big River arm of the lake before realising the captured Golden perch have the ability to return to their golden perch had a tag. They released the fish in home range if moved to another location. One the Big River arm. The fish was located in the Big golden perch, Tag 5, was captured in the Goughs River arm but again went missing. Several days Bay area of the lake (the other end of the lake later the tracking team found the fish back in the from the Delatite arm, see Figure 13 in Goughs Bay area, near where it was originally Appendix) but tagged and released in the captured. This isolated incident indicates that Delatite arm. The fish was tracked for some time perch may home and thus supports the findings before it was lost. The fish was subsequently that golden perch can move around the lake but captured by anglers back in the Goughs Bay area prefer certain areas. of Eildon. The anglers kept the fish in a live well

Figure 2. Detail of study area showing golden perch locations for whole of study, high water mark at full supply as blue line, and satellite image of representative lake height at time of study. Coloured dots represent separate fish.

Golden perch preferred habitat ANOSIM indicated no difference between the two data sets (Global R =‐0.0008, p= 0.604). associations No preferred habitat associations were observed in the study. The habitat parameters measure at each contact with golden perch were compared to the parameters obtained from randomly generated locations within the Delatite arm.

Golden perch movement and habitat 6 Lake shore

Monthly averages of the stratification index (ΔT) 25 are presented in Figure 3. The lake was strongly 20 stratified only in the summer months. 15 % Comparison of the depth of the lake at the 10 location of golden perch and the stratification 5 index indicated that the golden perch moved into shallower water as the lake stratified in the 0 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 summer months (Figure 4). The golden perch do metres not necessarily move closer to the banks. Overall only 18% of golden perch were located less than Figure 5. Percentage of golden perch located at 50 metres from the bank while nearly half of the various distances from bank (2002‐03 data). locations were greater that 100 metres from the bank. Percentage locations at various distances A comparison of monthly mean distances to the from the bank are presented in Figure 5. bank and time of year shows a trend of the fish coming nearer to the shore in December (Figure difference in temperature (ΔT) 6). There is some indication of a drop in the mean 0C 25 distance to shore in December. The difference is 20 probably not significant, and there is 68% 15 confidence that the true mean lies between the 10 5 extent of the error bars (Figure 6). The spread of 0 the error bars reflects a larger variation in the -5 -10 range of distances recorded and, therefore, while

2 2 2 3 it may not be statistically significant, 0 0 0 -02 -0 pr- Jul-02 ec Mar-02A May-02Jun-02 Aug- Sep- Oct-02Nov-02D Jan-03Feb-03Mar-03Apr proportionally more fish were closer to the banks metres in December 2002 than at other months in the study (Figure 6). Comparing all distances to the Figure 3. Monthly mean of stratification index. banks from each golden perch location by date Higher values indicate larger temperature indicates that some fish are near the banks difference (stratification) between surface and throughout the winter and spring months (Figure deeper water. Negative values indicate surface 7). There is some indications that golden perch water is colder than deeper water, positive move away from the banks in late summer values indicate surface water is warmer than (January‐March) given the lack of observations of deeper water. golden perch near the banks at this time (Figures

stratification 6 & 7). index depth of lake at fish location (m) stratification index 25 14 400 w ater depth 20 12 350 15 10 300 10 8 250 5 6 200

0 4 metres 150 -5 2 100 -10 0 50 0 2 2 -02 -02 -0 -02 -02 03 -03 r l-0 p-02 b-03 r- r p ay ug e ct-02 ov ec e 2 2 2 2 3 Mar-02A Jun-02Ju O N Jan-03F Ma Ap 02 03 M A S D l 02 p 02 t 0 c 02 apr ay 0 jun 0 ju e oc e jan 0 feb 03 apr months mar 0 m aug 02s nov 02d mar 03 month Figure 4. Comparison of monthly stratification index and mean monthly depth of lake at Figure 6. Mean distances from bank for golden golden perch locations. perch locations by month (2002‐03 data). Error bars are standard error.

Golden perch movement and habitat 7 600

500 50 400 40

300 30 metres

metres 20 200 10 100 0 Mar- Apr- May- Jun- Jul- Aug- Sep- Oct- Nov- Dec- Jan- 0 24-May-02 13-Jul-02 1-Sep-02 21-Oct-02 10-Dec-02 29-Jan-03 20-Mar-03 02 02 02 02 02 02 02 02 02 02 03 dates fish located months

Figure 7. Distance from shore for all dates for Figure 9. Mean distances from standing timber all golden perch located during the study. for golden perch locations by month (2002‐03 data). Error bars are standard error. Standing dead trees A comparison between the mean monthly A prominent feature of Lake Eildon is the distance to standing dead trees and the presence of standing dead trees. Almost 90% of stratification index suggests that the golden golden perch were located within 40 metres of perch may move closer to the cover in late spring standing dead trees, with 73% of golden perch and early summer as the lake begins to stratify located within 20 metres of such cover (Figure 8). (Figure 10).

Stratification Distance to index standing dead 60 25 trees 35 20 30 50 15 25 40 10 20 % 30 5 15 20 0 10 10 -5 5 0 -10 0

0 102030405060708090100110120130 2 2 3 0 -02 -02 -02 0 metres un-02Jul ct-02 ov ec Mar-02Apr- May-0 J Aug-02Sep-02O N D Jan-03Feb-03Mar-03Apr- months

Figure 8. Percentage of golden perch located at Figure 10. Comparison of stratification index various distances from standing timber (2002‐03 and mean monthly distance to standing dead data). trees. Stratification index is in degrees Celsius On a seasonal basis, the monthly mean distance and distance to trees is in metres. to standing timber decreased in the summer Water temperature months. For the majority of the year the golden Anglers may have the means to measure surface perch appeared to be located away from standing water temperature via handheld thermometers timber (>10 m) but from October to January there or depth sounders equipped with temperature was a trend where the fish moved much closer probes. Linking surface water temperature to (Figure 9). golden perch movement seems a logical task to assist anglers to locate golden perch. The comparison of lake depth at the fish, surface water temperature, distance to bank and distance to standing trees is presented in Figure 11. There is a trend for golden perch to move into shallower water, closer to the bank and to standing trees as the lake surface temperature rises in late spring‐summer.

Golden perch movement and habitat 8 distance from bank Golden perch activity and depth

400 distance to standing 30 timber Swimming speed was used as a measure of 350 surface water temp 25 activity. Golden perch swimming at higher 300 lake depth at fish speeds were considered to be more active. Eight 20 250 of the 10 golden perch fitted with radio telemetry 200 15 tags were subsequently located and tracked 34 Distance (m) 150 times for the activity and depth investigations 10 Temperature (C) 100 between February and June 2003. 5 50 Diurnal activity 0 0 mar apr may jun jul aug sep oct nov dec jan feb mar apr 02 02 02 02 02 02 02 02 02 02 03 03 03 03 There was a trend for the fish to move more at

night (mean 8.5 metres/minute at night compared Figure 11. Water temperature compared to to mean 2.9 metres/minute in the day) but it was golden perch distance to bank, depth of the not statistically significant (p = 0.09). lake at the fish and golden perch distance to standing trees in Lake Eildon in 2002‐03. Error bars are standard error. Table 2. Details of golden perch implanted with radio tags and used in activity and depth investigations

Released Length (TL) Weight (G) Dart Tag No Frequency Release area 14/12/2003 540 2872 3449 150.654 Delatite 14/12/2003 480 1990 3448 150.753 Delatite 14/12/2003 415 1200 3450 150.794 Delatite 14/12/2003 453 1568 3447 150.614 Delatite 14/12/2003 415 1228 3446 150.732 Delatite 14/12/2003 490 2206 3445 150.674 Delatite 14/12/2003 399 1030 3444 150.772 Delatite 14/12/2003 488 2405 3443 150.693 Delatite 14/12/2003 430 1420 3442 150.714 Delatite 14/12/2003 445 1820 3441 150.633 Delatite

Seasonal activity Depth Twelve observations were made during the day There was no significant difference in the depth in summer and five at night. Seventeen of golden perch between day and night or observations were made during winter in between summer and winter. Just under 60% of daylight only. The data from summer were all depth readings were located within 2 metres pooled and compared to the winter samples of the substrate (Figure 12). Golden perch are not (n=17). While the average activity (movement) always associated with the lake‐bed and were was higher in the summer (mean 5.8 sometimes further up in the water column. There metres/minute in summer, mean 1.6 is a trend for golden perch to be further off the metres/minute in winter) there was not a lake‐bed as the lake depth increases (Figure 13). statistical difference (p =0.07) between the activity of golden perch on a seasonal basis.

Golden perch movement and habitat 9 % of fish 30 Modelling golden perch depth 25 A stepwise regression was undertaken to 20 determine the relationship between the depth of 15 the fish and environmental conditions of surface 10 water temperature, bottom water temperature, 5 and surface and bottom DO. The regression 0 indicated that a combination of these factors 0 1 2 3 4 5 6 8 9 101112131415161718 could only explain about 43% of the variation in Distance from lake bed (m) fish depth (R‐square = 0.4257). The model is: Figure 12. Percentage distribution of golden Golden perch depth = 6.6 ‐ 0.69 surface water perch observations from lake‐bed. temperature + 0.4 lake depth + 0.67 lake bottom water temperature ‐ 0.29 dissolved oxygen at the 20 Distance from lake bed (m) = 0.907 Lake depth (m ) - 6.036 bottom. 18 16 14 12 10 8 6 4

Distance from lake bed (m 2 0 0 5 10 15 20 25 Lake depth (m)

Figure 13. Regression of distance of golden perch from lake bed with lake depth (R2 = 0.66596).

Golden perch movement and habitat 10 Discussion

Spatial distribution and in activity of the fish that coincided with the increase in water temperature and the lake movement of golden perch in beginning to stratify. The individual variability lakes and rivers and small sample size may have masked the statistical significance. Relatively high activity Site fidelity is common in many species of rates indicate that some fish are quite active at freshwater fish (Matheney 1995, Warden 1975, this time. The present study observed that golden Chilton and Paorch 1997, Crook 1999) and has perch come near the bank throughout most of the been reported for several Australian freshwater year, including the colder months. The fish do species in rivers including golden perch (Crook appear to move away from the banks as summer 2003), Mary River cod, (Simpson 2002), Murray progresses. This behaviour has been noted by cod (Koehn 1996) and (Pers. Com. some anglers who suggest that the timing of Simon Nicol, Department of Sustainability and movement coincides with increased boating Environment, Arthur Rylah Institute). Whilst the activities such as water skiing (Pers. Com. Bill golden perch generally remained in the one area Classon, Freshwater Fishing Australia publisher). of Lake Eildon, the actual home range was quite The timing of movement also coincides with large and consisted of almost the entire area of falling lake water levels. Despite this dispersal, the Delatite arm. The size of the home range of there is a message for anglers that some golden these lake fish contrasts with the smaller home perch are near the banks in winter (and probably ranges of the riverine golden perch reported by almost as active as they are during summer), as Crook (2003) and suggests that lacustrine golden well as spring and early summer. Also the timing perch may prefer or require a large area in which of the golden perch becoming active in late to forage. Scale is important when investigating spring may be connected to the lake beginning to home range and site fidelity (Crook 2003). The stratify and monitoring of lake water spatial distribution of Lake Eildon golden perch temperatures may give anglers a clue as to when was found to be dependent on the scale at which they should start fishing the banks. it was examined. At a small scale, ie the lake arm, the golden perch in the present study did not all Apart from movement away from the banks, display site fidelity and some of the fish there is also a relationship of golden perch being movements were considered random. At the further away from the lake‐bed as the lake depth larger scale of the whole lake, golden perch increases. This implies that in deeper water over exhibited site fidelity with the Delatite arm of the 10 metres, golden perch remain in the water lake. The fish do not roam about the whole lake column and not near the substrate. It is likely that but tend to have areas in which they reside, and this is due to water stratification as in summer return to if displaced. Lake Eildon stratifies and both dissolved oxygen and water temperature are lower below the Movement and angling thermocline. This condition may prevent golden perch from going below the thermocline. The The smaller fine‐scale movement of golden perch observations from the present study indicate that within their home range is of interest to anglers. golden perch do not go much deeper than about If the fish are at certain areas at certain times, 10 metres. If the depth of the lake is below 10 then anglers may be able to target these areas metres the golden perch can utilise anywhere and meet with more fishing success. There is a from the lake‐bed to the surface. In deeper water general feeling amongst native fish anglers that the thermocline may restrict golden perch from native fish come closer to the bank as the water going deeper. The stratification of the lake may warms in the spring (Sissins 1999) and increases explain why golden perch remain in the Delatite in golden perch captures are reported by arm. The arm is relatively shallow and the depth recreational anglers from Lake Eildon from in many places is above the depth of the October to December (Harmon 2003). While the thermocline. Therefore golden perch can utilise present study found a trend of the golden perch much of the substrate in this area. In the main coming closer to the banks in November and arm and deeper sections of the lake the available December, the trend was not statistically suitable habitat is restricted to the very margins significant. There also appeared to be an increase

Golden perch movement and habitat 11 of the lake because of the steep banks and deeper perch. Cadwallader and Backhouse (1983) water. suggested that redfin are often associated with cover although they may also be pelagic in lakes. The study suggests that in late summer golden They also reported that adult redfin may move perch are often located close to standing dead into shallow water in spring and possibly stay in trees, away from the banks and in deeper water, the area for some time. In European lakes, within the first 10 metres of the water column. juvenile redfin have been found to aggregated in Given observations of golden perch in the open dense schools in the warmer parts of the water water near the surface, trolling in these areas during the day (Masson 2001). If small redfin may be an option. seek the warmer parts of the water then they may Movement hypothesis tend to congregate in the shallow margins of the lake in winter and spring. It is possible that the Habitat selection has been defined as the non‐ predatory golden perch may frequent the area at random use of space as a result of voluntary the same time. As the water temperature movement in response to many co‐varying increases in summer and autumn, the redfin may factors (Crawshaw and O’Connor 1997, in Sims spread out in to the open water and the golden 2003, Kramer et al. 1997, in Sims 2003). One of perch may follow. On one occasion, some golden these co‐varying factors is likely to be food. The perch were observed within 1 metre of the distribution of predators can be influenced by surface in the middle of the Delatite arm well prey distribution (Heard et al. 2004). In fish, Coho away from the banks and timber. The salmon have been reported to forgo areas of observation was made on a relatively windy day. woody material that offered shelter for areas At the time there were many dead or dying where food was more abundant (Giannico 2000). redfin (from an EHN viral outbreak) and many Studies of distribution of golden perch larvae could be found concentrated in the long slicks or suggested that dispersal of larvae might be windlanes out in the middle of the lake. It is indirectly related to food availability (Gehrke conceivable that these golden perch were feeding 1991). In impoundments, golden perch have been (possibly on the redfin) in these surface reported near schools of baitfish by recreational windlanes. Such behaviour is common with anglers (Bethune 2004). Anglers have also impoundment trout feeding on suggested that in impoundments including concentrations of plankton. have changed from their riverine habits of holding around snags and are commonly found Diel movement out in the open water where they actively feed on Diel horizontal and vertical migrations have been pelagic fish and are often in the vicinity of bony reported from many fish species and vertical bream schools (Morgan 2004). Golden perch are migration behaviour is more common in lakes sometimes caught as bycatch of anglers targeting (Levy 1991, in Lucas and Baras 2001). Vertical these bass (Pers. Comm. Rod Cheetham, migrations have been linked to a number of Queensland Department of Primary Industries factors including following movements of prey, and Fisheries). Bony bream do not occur in Lake moving into deeper (and darker) water to avoid Eildon, but redfin and roach are present. Redfin predators and/or as a method of maintaining are known to be a source of food for Lake Eildon homeostatic controls (Brett 1971, in Lucas and golden perch as fish up to about 8 cm total length Baras 2001). In riverine environments there was a are a common item in the golden perch diet trend for perch to disperse at night and utilise (unpublished PIRVic data and Pers. Com. more habitat than during the day (Crook et al. Andrew Pickworth, Department of Primary 2001). The Lake Eildon golden perch showed no Industries technician, Snobs Creek). In Lake daily pattern in either activity levels or position Eildon, schools of small redfin (up to about 12 cm in the water column between day and night. Diel in length) are often seen swimming near the activity may not occur in lacustrine golden perch. shoreline or in the branches of sunken trees. If Predator avoidance is not considered to be redfin are a major source of prey for golden required for Lake Eildon golden perch as fish of perch then it is possible that the distribution of the size that were tagged would have few redfin may influence the distribution of golden predators in the lake.

Golden perch movement and habitat 12 Conclusions

• Golden perch have home ranges, ie have site the water temperature warms; the fish tend affinity with a certain area to move offshore in mid to late summer • The home ranges of golden perch are • Some golden perch are near the banks all relatively larger in impoundments than the year and are equally as active in winter as in home ranges reported from streams summer; a winter fishery in Lake Eildon for golden perch may be an option • Golden perch appear to have the ability to return to their home range after being • Anglers wishing to target golden perch in moved to another location ie display the spring to early summer should fish near homing behaviour the banks when the fish appear to be closer to the shore; the presence of trees or steep • There is no strong association of golden banks does not appear to be needed perch with any particular type of habitat in Lake Eildon. Golden perch appear to • Anglers wishing to target golden perch in display some trends in preferring different the late summer should possibly try the areas of the lake at different times of the heads of standing dead trees and fish in the year upper 10 metres of the water column and above the thermocline if it can be detected. • Golden perch show a trend in seasonal movement pattern that see them come closer to the shore in spring and early summer as

Golden perch movement and habitat 13 References

Battaglene S, Harris J, Gordon G (1991) water quality or food distribution? Australian Movement of tagged golden perch in Lake Journal of Marine and Freshwater Research Keepit (abstract) ASFB Newsletter 21(2), 25. 42(6), 707‐719. Bethune J (2004) When the going gets tough. Giannico GR (2000) Habitat selection by juvenile Freshwater Fishing Australia 67, 39‐42. coho salmon in response to food and woody debris manipulations in suburban and rural Brown P (1998) ‘Eppalog98 Lake Eppalock streams. Canadian Journal of Aquatic Science 57, Fisheries Assessment Using Angling Methods 1804‐1813. and Fishery Independent Methods, April 1998’ (Marine and Freshwater Resources Institute, Hall K, Brown P (2002) ʺLake Eppalock Fisheries Snobs Creek). Assessment, DNRE Northern Region, September 2000.ʹ (Marine and Freshwater Resources Brown P, Hall K (2003) ʹLake Eppalock golden Institute, 02/4, Snobs Creek). perch stock assessmentʹ Fisheries Victoria Report Series, No 6, Snobs Creek Harmon J (2003). Eildonʹs golden perch. Freshwater Fishing Australia 65, 114‐118. Cadwallader PL, Backhouse GN (1983) ‘A guide to the freshwater fish of Victoria’. (Ministry for Heard GW, Black D, Robertson P (2004) Habitat Conservation, Victoria). 249pp. use by the inland carpet python (Morelia spilota metcalfei: Pythonidae): Seasonal relationships Chilton EW, Paorch SM (1997) Distribution and with habitat structure and prey distribution in a movement behaviour of radio‐tagged grass carp rural landscape. Austral Ecology 29, 446‐460. in two Texas reservoirs. Transactions of the American Fisheries Society 126 467‐476. Hooge PN, Eichenlaub B (1997). Animal movement extension to arcview. Ver1.1., Alaska Crook DA, Robertson AI (1999) Relationships Biological Science Centre, U.S. Geological between riverine fish and woody debris. Marine Survey, Anchorage, AK, USA. and Freshwater Research 50, 941‐953. Koehn JD (1996) Habitats and movements of Crook DA (2003) Is home range concept freshwater fish in the Murray‐Darling Basin. In compatible with movements of two lowland ʹProceedings of the 1995 Riverine Research river fish? (In press). Forumʹ Brisbane, Australia. pp27‐32. (Murray‐ Crook DA, Robertson AI, King AJ, Humphreys Darling Basin Commission: Canberra) P (2001) The influence of spatial scale and Lucas M.C and Baras E (2001) ʹMigrations of habitat arrangement on diel patterns of habitat freshwater fishesʹ. Blackwell Science. 420 p. use by two lowland river . Oecologia 129, 525‐533. Masson S, Angeli N, Guillard J, Pinel‐Alloul B (2001) Diel vertical and horizontal distribution Dedual M (2000) Distribution and movements of of crustacean zooplankton and young of the brown (Salmo trutta) and rainbow trout year fish in a sub‐alpine lake: an approach based (Oncorhynchus mykiss) in Lake Otamangakau, on high frequency sampling. Journal of central North Island, New Zealand. New Plankton Research. 23(10) 1041 Zealand Journal of Marine & Freshwater Research 34, 615‐627. Matheney MP, Rabeni CF (1995) Patterns of movement and habitat use by northern hog Gehrke PC. (1991) Avoidance of inundated suckers in an Ozark stream. Transactions of the floodplain habitat by larvae of golden perch American Fisheries Society 124, 866‐897. (Macquaria ambigua Richardson): influence of

Golden perch movement and habitat 14 Merrick (1984) ʹAustralian freshwater fishes.ʹ American Journal of Fisheries Management 17, (Griffith Press: ) 677‐686. Morgan S (2004) Spoon feeding‐better bass catching series. www.fishingmonthly.com.au/features/bass_arti cles/spoons/spoons.html Reynolds LF (1983) Migration Patterns of Five Fish Species in the Murray‐ System. Australian Journal of Marine and Freshwater Research 34: 857‐71. Robinson (1982) ʹThe ecology of golden perch (Macquaria ambigua) in Lake Burley Griffin and Lake Ginninderra.ʹ ACT Conservation Service, The Conservation Memorandum No. 11, Department of the Capital Territory. Ross MJ, Kleiner CF (1982) Shielded‐needle technique for surgically implanting radio‐ frequency transmitters in fish. The Progressive Fish‐Culturist 44, 41‐43. Simpson RR, Mapleston AJ (2002) Movements and habitat use by the endangered Australian freshwater Mary River cod, Maccullochella peelii mariensis. Environmental biology of fishes 65,401‐410. Sims DW (2003) Tractable models for testing theories about natural strategies: foraging behaviour and habitat selection of free ranging sharks. Journal of fish biology 63 (supplement A) 53‐73.

Sissons, B (1999) Southern gold, Lake Eppalock. Freshwater Fishing Australia. 46, 4‐11. Tunbridge BR, Rogan PL (1991). ʹA guide to the inland angling waters of Victoria.ʹ (Department of Conservation and Environment: Melbourne) Warden RL Jr, Lorio WJ (1975) Movements of largemouth bass (Micropterus salmonides) in impounded waters as determined by underwater telemetry Transactions of the American Fisheries Society 104 698‐702. Wilkerson ML, Fisher WL (1997). Striped bass distribution, movements and site fidelity in Robert S. Kerr Reservoir, Oklahoma. North

Golden perch movement and habitat 15 Appendix 1‐ Individual golden perch locations for 2002‐03 tracking

Figure 14 Golden perch ʺTag 2ʺ locations for whole study

Figure 15 Golden perch ʺTag 4ʺ locations for whole study

Golden perch movement and habitat 16

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Figure 16 Golden perch ʺTag 5ʺ locations for whole study. Lines indicate movement direction of fish. Fish released in study area (small square) but moved to other end of lake

Figure 17 Golden perch ʺTag 6ʺ locations for whole study

Golden perch movement and habitat 17

Figure 18 Golden perch ʺTag 9ʺ locations for whole study

Figure 19 Golden perch ʺTag 10ʺ locations for whole study

Golden perch movement and habitat 18 Acknowledgements

Thanks are given to Russell Strongman, Andrew Pickworth, Daniel Stoessel, Michael Bretherton and Joel Tyndall for undertaking the fish capture, surgery and tracking components of the study. Wayne Fulton, Paul Brown and Kylie Hall made comments on the manuscript.

Golden perch movement and habitat 19