Error! No text of specified style in document. Growth, Movement and Survival of Stocked in Impoundments and Waterways of 1987-2008

Report prepared for Queensland Primary Industries and Fisheries by Infofish Services

Bill Sawynok and John Platten Infofish Services PO Box 9793 Frenchville Qld 4701

Published June 2009

Cover: Cover design by All-Biz-Art

Information in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought.

Infofish Services have taken all steps to ensure the information contained in this publication is accurate at the time of publication. Readers should ensure that they make the appropriate enquiries to determine whether new information is available on a particular subject matter.

Report No: STSG-2008-21

 Infofish Services All rights reserved. No part of this publication may be reprinted, reproduced, stored in a retrieval system or transmitted, in any form or by any means, without prior permission from Infofish Services.

page 1 Table of Contents

Acknowledgements...... 5 1. Summary...... 6 1. Introduction...... 10 2. Tagging of stocked fish in geographic divisions...... 11 2. Aims...... 14 3. Methods ...... 14 3.1 Growth of Stocked Fish ...... 14 3.2 Movement of Stocked Fish...... 15 3.3 Survival of Tagged Fish Released in Batches...... 16 3.4 Survival of Fish in Impoundments where Low Water Levels were experienced ...... 16 4. Growth of Stocked Fish ...... 17 4.1 Growth of Stocked ...... 17 4.2 Growth of Tagged Barramundi Released in Batches ...... 20 4.3 Growth Curves for Barramundi ...... 26 4.4 Discussion on Barramundi Growth...... 27 4.5 Growth of Stocked Australian Bass...... 27 4.6 Growth Curve for Australian Bass ...... 29 4.7 Discussion on Australian Bass Growth ...... 29 4.8 Growth of Stocked ...... 30 4.9 Growth Curves for Golden Perch ...... 31 4.10 Discussion on Growth of Golden Perch...... 31 5. Movement of Stocked Fish...... 32 5.1 Movement of Stocked Barramundi...... 32 5.2 Discussion on Barramundi Movement...... 49 5.3 Movement of Stocked Australian Bass...... 50 5.4 Discussion on Australian Bass Movement...... 55 5.5 Movement of Stocked Golden Perch...... 55 5.6 Discussion on Golden Perch Movement...... 60 6. Survival of Tagged Fish Released in Batches...... 61 6.1 Batch Releases of Barramundi...... 61 6.2 Batch Release of ...... 70 6.3 Discussion on Survival of fish in Batch Releases...... 71 7. Survival of Fish in Impoundments where Low Water Levels were experienced ...... 73

page 2 7.1 Low Water Levels and Australian Bass and Golden Perch...... 73 7.2 Discussions on Low Water Levels...... 76 8. Implications for Future Stocking...... 78 List of Figures Figure 1: Geographic divisions based on catchments where stocking has occurred 11 Figure 2: Locations where fish have been tagged in impoundments and waterways 1987-2008 13 Figure 3: Average annual growth rate for stocked Barramundi and natural populations (red) for comparison 19 Figure 4: Growth of Barramundi released in batches into Lake Tinaroo in 2003 and 2004-05 21 Figure 5: Growth of Barramundi released in batches into Trinity Inlet and the Barron River from 2002 to 2005 22 Figure 6: Growth of Barramundi released in batches in Black and Aplin Weirs on the Ross River in 2000 and 2007 23 Figure 7: Growth of Barramundi batch released into Alligator Creek (Fitzroy River) in 2005 24 Figure 8: Growth of Barramundi batch released into Moura Weir in 2005 and 2006 24 Figure 9: Growth of Barramundi released in batches into in 1998 and 2000 25 Figure 10: Growth curves for freshwater stocked locations compared to the Fitzroy River estuary 26 Figure 11: Summary of annual growth rates for stocked Australian Bass and Noosa River fish 28 Figure 12: Growth curves for Australian Bass in a number of impoundments and Noosa River 29 Figure 13: Summary of annual growth rates for stocked Golden Perch and for Dawson River fish 30 Figure 14: Growth curves for Golden Perch in 3 impoundments 31 Figure 15: Movement of Barramundi stocked in Trinity Inlet and Barron River 34 Figure 16: Movement of Barramundi stocked in Mulgrave and Russell Rivers 35 Figure 17: Movement of Barramundi stocked in Johnstone River 35 Figure 18: Locations where Barramundi tagged in the Johnstone River have been recaptured elsewhere 36 Figure 19: Where Barramundi tagged in Ross River weir pools were recaptured 37 Figure 20: Stocked Barramundi in Ross River weir pools and monthly rainfall from 1994-2008 37 Figure 21: Flow over Aplin Weir in February 2007 38 Figure 22: Flow over Black Weir in February 2007 38 Figure 23: Movement of Barramundi stocked in Ross River weir pools 39 Figure 24: Locations where stocked Barramundi tagged in Ross River weir pools have been recaptured outside the river 39 Figure 25: Movement of wild Barramundi tagged in the Haughton River 40 Figure 26: Movement of stocked Barramundi in Clare Weir 40 Figure 27: Movement of tagged Barramundi stocked in Clare Weir 41 Figure 28: Movement of tagged stocked Barramundi in Hedlow Creek and Serpentine Lagoon 41 Figure 29: Movement of tagged stocked Barramundi in Moura Weir 42 Figure 30: Movement of tagged stocked Barramundi in Bedford Weir 43 Figure 31: Movement of stocked tagged Barramundi in Alligator Creek and at Laurel Bank on the Fitzroy River 43 Figure 32: Movement of wild fish tagged in the Fitzroy River estuary 44 Figure 33: Movement of tagged Barramundi from stocking locations to the Fitzroy River estuary and beyond 44 Figure 34: Comparison of river flows at Riverslea on the Fitzroy River and Barramundi stocked and tagged at Hedlow Creek, Serpentine Lagoon, Alligator Creek and Laurel Bank on the Fitzroy River 45 Figure 35: Stocked tagged Barramundi released at Laurel Bank on the Fitzroy River and recaptured in Frogmore Lagoon 46 Figure 36: Movement of stocked fish tagged in Lake Callemondah 47 Figure 37: Movement of stocked Barramundi tagged in Lake Callemondah 47 Figure 38: Comparison of monthly rainfall at Gladstone and Barramundi stocked and tagged in Lake Callemondah 48 Figure 39: Lake Callemondah dam wall in a low flow event 48 Figure 40: Distance moved compared with days out for Australian Bass in Lake Somerset 52 Figure 41: Australian Bass tagged in Lake Somerset and recaptured outside the lake 52 Figure 42: Distance moved compared with days out for Australian Bass in Lake Boodooma 53 Figure 43: Australian Bass tagged in Lake Boondooma and recaptured outside the lake 53 Figure 44: Distance moved compared with days out for Australian Bass in Noosa River 54 Figure 45: Recaptures of tagged Australian Bass outside the tagging area in the Noosa River 54 Figure 46: Distance moved compared with days out for Golden Perch in Lake Somerset 57 Figure 47: Golden Perch tagged in Lake Somerset and recaptured outside the lake 57 Figure 48: Distance moved compared with days out for Golden Perch in Lake Boondooma 58

page 3 Figure 49: Golden Perch tagged in Lake Boondooma and recaptured outside the lake 58 Figure 50: Distance moved compared with days out for Golden Perch in Dawson River 59 Figure 51: Movement of tagged Golden Perch in the Dawson River 59 Figure 52: Recapture rates of batches of tagged Barramundi stocked into Lake Tinaroo 62 Figure 53: Recapture rates of batches of tagged Barramundi stocked in the Cairns area 63 Figure 54: Recapture rates for Barramundi released at different site in Trinity Inlet in December 2002 64 Figure 55: Recapture rates for Barramundi released at different sites in Trinity Inlet and Barron River in February 2004 64 Figure 56: Recapture rates of batches of tagged Barramundi stocked in Ross River weirs 65 Figure 57: Recapture rates of batches of tagged Barramundi stocked in Clare Weir 66 Figure 58: Recapture rates of batches of tagged Barramundi stocked in Lake Awoonga 69 Figure 59: Barramundi tagged and recapture rates in a number of Queensland waterways 70 Figure 60: Fish tagged and released each month and water levels in Lake Boondooma from 2001/02 to 2008/09 74 Figure 61: Fish tagged and released each month and water levels in Lake Barambah from 2001/02 to 2008/09 74 Figure 62: Fish tagged and recaptured in Lake Moogerah from 1989/90 to 2000/2001 75 Figure 63: Fish tagged and recaptured each month in Lake Moogerah compared with dam levels from 2001/02 to 2007/08 76 List of Tables Table 1: Summary of growth of Barramundi in stocking divisions with natural populations for comparison ...... 18 Table 2: Summary of tagged Barramundi released in batches from 1996-2008...... 21 Table 3: Summary of recaptures and annual growth rates for stocked Australian Bass and for Noosa River fish ...... 28 Table 4: Maximum time at liberty for recaptured Australian Bass ...... 29 Table 5: Summary of recaptures and annual growth rates for stocked Golden Perch ...... 30 Table 6: Maximum time at liberty for recaptured Golden Perch ...... 31 Table 7: Summary of Barramundi movements outside impoundment or waterway ...... 33 Table 8: Summary of Barramundi movement (km) outside of impoundments or waterways ..... 33 Table 9: Summary of Barramundi tagged and recaptured in Ross River weirs...... 36 Table 10: Summary of Australian Bass movements outside impoundments ...... 50 Table 11: Summary of Australian Bass movements...... 51 Table 12: Summary of Golden Perch tagged and recaptured and movements outside impoundments ...... 56 Table 13: Summary of Golden Perch movements...... 56 Table 14: Barramundi tagged and stocked in batches and recaptured in Lake Fred Tritton ...... 61 Table 15: Barramundi tagged and stocked in batches and recaptured in Lake Tinaroo ...... 61 Table 16: Barramundi tagged and stocked in batches in the Cairns area ...... 62 Table 17: Barramundi tagged and stocked in batches and recaptures in Black Weir...... 65 Table 18: Barramundi tagged and stocked in batches and recaptured in Lake Dalrymple ...... 65 Table 19: Barramundi tagged and stocked in batches and recaptured in Clare Weir...... 66 Table 20: Barramundi tagged and stocked in batches and recaptured in Barratta and Sheepstation Creek...... 67 Table 21: Barramundi tagged and stocked in batches in Lake Proserpine ...... 67 Table 22: Barramundi tagged and stocked in batches in the Fitzroy Basin ...... 67 Table 23: Barramundi tagged and stocked in batches and recaptured in Lake Awoonga ...... 68 Table 24: Barramundi tagged and recaptured in a number of Queensland waterways ...... 70 Table 25: Murray Cod tagged and stocked in batches and recaptured in Lake Coolmunda ...... 70 Table 26: Summary of fish tagged and recaptured each year in Lakes Boondooma, Barambah and Moogerah (*2008/09 to 31/12/2008)...... 73

page 4 Acknowledgements

This report covers a time span of 20 years and there are many groups and individuals that have contributed in some way to the generation of information contained in this report. It is not possible to acknowledge the contributions of everyone involved however it is important to provide acknowledgement to the greatest contributors.

The support of Queensland Primary Industries and Fisheries (QPI&F) in the Department of Employment, Economic Development and Innovation (DEEDI) is acknowledged for the Suntag program over that time. The QPI&F has provided funding for Suntag over that 20 year period and funding for this and other reports was provided from the Living the Queensland Lifestyle program of the Queensland Government.

The support of the Australian National Sportfishing Association Queensland Branch (ANSA Qld) is also acknowledged. ANSA Qld has been responsible for the Suntag program over the past 20 years while it has contracted the delivery of the program to Infofish Services since 1996. The continued support of the ANSA Qld state executive and ANSA Qld sportfishing clubs is acknowledged.

Acknowledged is the contribution of all ANSA Qld members that have tagged fish in stocked impoundments and waterways.

The support of the Freshwater Fish Stocking Association of Queensland (FFSAQ) and its Executive Officer Les Kowitz is also acknowledged. FFSAQ has provided long term support for the involvement of stocking groups in Suntag.

Also acknowledged is the contribution of all members of stocking groups that have tagged fish in stocked impoundments and waterways.

page 5 1. Summary

This is 1 of 3 reports examining fish stocked and tagged in impoundments and waterways of Queensland. The reports are:

 Summary of tagging of stocked fish in impoundments and waterways of Queensland 1987-2007  Winter 2007 fish death events: Impact on stocked fish  Growth, movement and survival of stocked fish from tagging programs in impoundments and waterways of Queensland 1987-2008

The aims of this report were to analyse tagging data from stocked fish from 1987- 2008 in relation to:

 Growth of stocked fish in impoundments and waterways  Movement of stocked fish beyond the impoundment or waterway  Survival of tagged fish released in batches  Survival of fish in impoundments where low water levels were experienced  Implications for future stocking

Tagging of stocked fish has occurred in 66 impoundments and waterways in 6 geographic divisions in Queensland.

Annual growth rates were calculated for Barramundi in 22 impoundments and waterways and a further 5 natural river systems for comparison. The lowest average annual growth rate was 86.3mm for fish in however this was for only 9 large fish with an average length of 790.3mm when tagged. The highest average annual growth rate was 360.7mm for Lake Fred Tritton however these were small fish tagged recently at an average length of 299.3mm and were mostly recaptured within a few months when growth rates are highest. Growth rates were generally higher in the freshwater impoundments and waterways than in estuaries.

Growth of Barramundi released in batches were generally similar for batches released at different times in the same impoundment or waterway, although many batch releases were made in recent years since 2002 and data on recaptures is still being received. From 1996-2008 there were a total of 59,692 fish released in batches in 25 impoundments and waterways. Of these there were 991 (1.7%) recaptures and 931 (1.6%) with sufficient data to calculate growth.

Growth curves were generated for 12 batch releases into 6 impoundments and waterways. Three batch releases of fish have had recaptures of fish that have now been at liberty for over 7 years (2,555 days). These were batch releases in Lake Awoonga in 1998 and 2000 and a release in Black Weir in 2000. Fish in Lake Awoonga were generally over 1000mm long after 5 years (1,825 days) while fish released in Black Weir were generally only 800-900mm after that time.

For Lake Tinaroo fish from the batch release in 2002 have been recaptured up to almost 5 years (1,812 days) after release. There has only been 1 fish recaptured after that time and it was 900mm long.

Growth curves using GROTAG were generated for a number of stocking locations in the Fitzroy basin and impoundments at Gladstone, and compared with growth curves for the Fitzroy estuary. These showed the growth rate for fish in freshwater was higher than for fish in saltwater except for one location. Fish grew faster in the early years in Moura Weir, Bedford Weir, Alligator Creek, Fitzroy River (freshwater) Lake Callemondah and Lake Awoonga. Only fish in Hedlow Creek had similar growth to fish in the estuary.

Growth rates for fish stocked in wet tropic locations are generally lower than for other locations. Growth rates for the natural population of fish at Weipa are the lowest recorded for any location and supports this being a genetically distinct strain of Barramundi.

page 6 Growth rates for the same location can also vary over time. The batch releases of Barramundi at particular locations show similar growth rates over different years. However for Black and Aplin Weirs there appears to be a higher growth rate for fish released in 2007 compared with those released in 2000. More recapture data for fish released in 2007 is needed to confirm this. This could be related to different environmental conditions between the years or to the genetics of the broodstock used.

Growth rates of Australian Bass were calculated for 9 impoundments and the Noosa River for comparison with a wild population. Growth curves were generated and compared for Lake Somerset, Lake Boondooma, Lake Cressbrook, Lake Moogerah and the Noosa River. Growth rates for the impoundments were mostly higher than for the Noosa River except for Lake Cressbrook where the growth rate was similar to that of the river. As the lake is at a higher altitude than the other impoundments it could be related to overall cooler water temperatures.

Growth rates for Golden Perch were calculated for 4 impoundments and the Dawson River for comparison. Growth curves were generated and compared for Lake Boondooma, Lake Somerset and Lake Leslie. Growth rates in 3 of the impoundments were similar to those in the Dawson River while the only impoundment where growth was significantly different (higher) was in Lake Leslie. The reason for such a difference is unknown.

Movement of fish was assessed by examining fish that were recaptured within or outside the impoundment or waterway they were tagged in.

For Barramundi there were 46 impoundments where stocked Barramundi have been tagged. A total of 72,242 fish have been tagged with 2,250 (3.1%) recaptures of which 403 (17.9%) were recaptured outside the impoundment or waterway they were tagged in. There were 24 (52%) locations where fish were recaptured outside the impoundment or waterway in which they were tagged.

Of the fish recaptured away from where tagged only 3 were recaptured upstream while 400 were caught downstream. The average distance moved ranged from 2.6km for Aplin Weir to 142.9km for Serpentine Lagoon. Most fish have been recaptured within 20km from where they were released and the movement from the system they were tagged in to other systems was low at less than 5%.

For and Lake Dalrymple there were 3 fish recaptured outside of each impoundment. Both lakes have high dam walls and these fish survived going over the wall. At both locations dead Barramundi have been recorded following water flowing over the spillway but some fish do survive.

For fish tagged in 3 weir pools on the Ross River no fish were caught above the weir pool they were tagged in, 66.6% of fish were caught in the same pool, 10.1% were recaptured in a downstream weir pool while 23.3% were recaptured below all weir pools in the Ross River estuary and beyond.

Barramundi have not moved far at most locations. The exception is the Fitzroy River where fish from locations over 500km upstream were able to migrate to the estuary when suitable flows occur. There were 2 flow events when fish stocked in upstream locations were able to migrate to the Fitzroy River estuary. These were a large flow in January 2003 and a flood in January-February 2008. Following both these flows there were fish recaptured in the estuary that had been stocked in Moura Weir which is over 400km upstream. Following the 2008 flood there were 99 tagged fish recaptured in the Fitzroy River estuary by commercial and recreational fishers from February to June 2008. Of these 70 (70.7%) were stocked fish from upstream locations.

Lake Callemondah is a unique impoundment in which Barramundi have been stocked as it is the only one where fish leaving the lake immediately enter the estuary over a low weir wall where survival is high. Stocked fish have been tagged in the lake since 1999. Fish left the lake and entered the estuary on 2 large flow events, one in February 2003 and another in January 2008. Of 103 recaptures of fish tagged 59

page 7 (57.3%) have been recaptured outside the lake. The furthest distance a fish has moved from the lake is 36km.

For Australian Bass there have been 18 impoundments where fish have been tagged. A total of 35,999 fish have been tagged with 2,980 (8.3%) recaptures and of these 36 (1.2%) have been recaptured outside the impoundment they were tagged in. There were 5 impoundments where fish were recaptured outside the impoundment.

As most movements were confined to the impoundment the average distance moved is related to the size of the impoundment and ranged from 1.1km in Lake Moogerah to 6.9km in Lake Somerset.

Of the 36 recaptures outside their impoundment 3 were recaptured upstream while the remaining 33 were recaptured downstream. In moving downstream fish had to go over high dam walls at Lake Somerset, Lake Wivenhoe and Lake Boondooma. Of the 15 fish recaptured below Lake Somerset 8 fish were caught below the Lake Wivenhoe having survived going over both dam walls. A further 2 fish were recaptured at Colleges Crossing having also gone over and 1 fish was recaptured in the saltwater down at the Gold Coast 290km downstream from where it was tagged.

The low numbers of Australian Bass recorded as having moved outside the impoundment where stocked is also likely to be the result of prolonged dry and drought periods during the years following tagging. This would have limited the opportunity for fish to move outside the impoundment. It is likely in wetter years where high flows and overflows from impoundments occur that a greater number of fish would move outside their impoundment.

There were 17 impoundments and 1 river where Golden Perch have been tagged. A total of 10,849 fish have been tagged for 1,022 (9.4%) recaptures and of these 12 (1.2%) were recaptured outside the impoundment they were tagged in. There were only 2 impoundments where fish were recaptured outside the impoundment.

As most movements were confined to the impoundment the average distance moved is related to the size of the impoundment and ranged from 1.4km in Lake Cania to 4.1km in Lake Somerset.

Of the 12 recaptures outside their impoundment 7 (58.3%) moved upstream while the other 5 moved downstream. Upstream movements were recorded at Lake Somerset and Lake Boondooma. The downstream recaptures were all for fish tagged in Lake Somerset. Four were caught immediately below the Somerset wall or in Lake Wivenhoe. One fish was recaptured at Colleges Crossing having gone over the Somerset wall, Wivenhoe wall and Mount Crosby Weir.

Of the fish tagged in the Dawson River there were 18 recaptures where the fish moved with 17 having moved upstream and 1 downstream. Of the fish that moved upstream most were recaptured close to or at the base of the next weir upstream.

The low numbers of Golden Perch recorded as having moved outside the impoundment where stocked is also likely to be the result of prolonged dry and drought periods during the years following tagging. This would have limited the opportunity for fish to move outside the impoundment. It is likely in wetter years where high flows and overflows from impoundments occur that a greater number of fish would move outside their impoundment.

The recapture rates of tagged fish released in batches were examined to obtain an estimate of relative survival. Overall recapture rates for Barramundi released in batches ranged from 0% to 16.5% with an average recapture rate of 1.7%. This compares to an overall recapture rate of 10.4% for fish tagged in 6 natural systems.

Winter released of 5,338 tagged fish in 2004 and 2005 into Lake Tinaroo have resulted in 1 (0.0%) recapture. Winter releases of 6,567 tagged fish in Lake Awoonga in 1997 and 2000 have resulted in 1 (0.0%) recapture. It is likely that winter releases of tagged fish result in lower survival.

page 8 Releases of fish at different sites were able to be assessed for Trinity Inlet. There were releases at a number of sites in 2002 and 2004. There were 5 sites where releases were made in both years. At the Hills Creek site recapture rates were 4.2% and 3.2% for the 2 years. By contrast at Redbank Creek the recapture rates were 0.7% and 1.5%. Care needs to be taken in any interpretation of the results due to the low numbers of recaptures.

For batch releases of Barramundi there was little evidence of differences in the recapture rates for tagged fish stocked at lengths over 150mm. This would suggest that if larger fish are intended to be stocked then using fish around 150-200mm would be more economical than larger fish without any likelihood of a significant difference in survival.

There was a batch release of 196 Murray Cod in Lake Coolmunda in 2006 however to date no recaptures have been made.

Survival of fish in impoundments where low water levels were experienced was assessed by examining tagging and recaptures during and after low water levels. This was able to be assessed for fish tagged in Lake Boondooma, Lake Barambah and Lake Moogerah.

For Lake Boondooma the minimum water level was 10% in November-December 2007 however fish continued to be tagged and recaptured during and after the lowest water levels. Since October 2007 when water levels reached their lowest there have been 32 recaptures with 30 of these being fish tagged prior to October 2007 and as far back as 1999.

The evidence suggests that minimum water levels of 10% are not likely to have a significant impact on the survival of stocked fish.

Water levels in Lake Barambah reached a low of 2% and stayed below 5% for around 23 months from April 2006 to February 2008. A small number of fish were tagged and recaptured during the early part of this period however few fish have been tagged since then and after the water level rose again. There have been no recaptures after 18 months into that low water period and none since water levels rose again.

For Lake Moogerah there was no data on water levels available from 1989/90 to 2001/02 however during that period it was reported that water level reached a low of 1% during the drought of 1995. There were 1,787 fish, almost all being Australian Bass, tagged prior to that time and 227 (12.7%) were recaptured after that low level. This recapture rate indicates a high rate of survival as this compares with an overall recapture rate of 8.5% for stocked Australian Bass.

For other fish tagged in Lake Moogerah prior to periods of low water levels as low as 2.6% in 2002/03 and 2006/07 the recapture rates of fish caught after these low levels were 4.9% and 3.7%.

Based on the limited available data it is likely that, at least for Australian Bass, that fish can survive low water levels of around 5% and even 1% in the case of Lake Moogerah.

page 9 Growth, Movement and Survival of Stocked Fish in Impoundments and Waterways of Queensland 1987-2008

1. Introduction

During the 1980s the Queensland Government introduced the Recreational Fishing Enhancement Program which saw the start of stocking in impoundments and waterways on a statewide scale. Tagging of stocked fish commenced shortly after and has been incorporated into a broader monitoring program of stocked fish.

Tagging commenced in the mid-late 1980s carried out by members of Sportfishing clubs affiliated with the Australian National Sportfishing Association (ANSA) under the Recreational Sportfish Tagging Program (now Suntag). Taggers began to target stocked fish when they had reached a size of around 200mm which was considered large enough for them to be tagged. Tagging by Suntag taggers has continued since then. Some stocking groups also commenced tagging of their stocked fish, in the same way as Suntag taggers, in the late 1980s. Over the following years tagging of stocked fish by both Suntag taggers and stocking groups grew to become a significant component of the Suntag program.

QPI&F staff also tagged fish during their monitoring, which in the 1980s and 1990s was mostly through netting surveys. During the 2000s electrofishing surveys commenced and fish have also been tagged during these surveys.

A small number of tagged broodstock used in hatcheries have also been released when they are no longer required by the hatchery.

In the earlier years of the stocking program fish were generally released at small sizes from 25-50mm. In 1996 a batch of around 200 Barramundi from 210-350mm were tagged before release in Lake Awoonga. Similar releases of larger fish in Lake Awoonga continued through to 2000. In 2000 there was a release of 110 larger tagged 170-310mm fish in Black Weir. In 2002 northern stocking groups commenced releasing Barramundi, up to several thousand fish at a time, in larger sizes from 200- 400mm and all were tagged to improve the subsequent monitoring of these fish. Since then there have been continuing releases of batches of tagged Barramundi. There has also been a release of larger tagged Murray Cod in Lake Coolmunda.

This tagging has provided a significant amount of data that can be used to assist in understanding the results of stocking, especially when considered in combination with data obtained from other monitoring surveys and activities.

This report provides an analysis of that tagging data to assist Queensland Primary Industries and Fisheries and stocking groups to refine their stocking strategy into the future.

page 10 2. Tagging of stocked fish in geographic divisions

Stocking groups have been identified by geographic divisions within the State which are based on catchments that are associated with those geographic areas as shown in figure 1.1

North Qld Division

Gulf of Carpentaria Division

Murray / Darling Division

Central Qld Division

Mary / Burnett Division

South East Qld

Figure 1: Geographic divisions based on catchments where stocking has occurred

Reporting on the tagging of stocked fish is based around impoundments and waterways in each of the geographic divisions. The following impoundments and waterways are included in each division and are included in the analysis where there are sufficient data available. Figure 2 shows the locations of impoundments and waterways.

Gulf of Carpentaria  ()  Lake Moondarra (Mount Isa)  Lake Belmore (Croydon)  Chinaman Creek (Cloncurry)  Lake Fred Tritton (Richmond)  Lake Tinaroo (Atherton)  Barron River (Cairns)  Trinity Inlet (Cairns)  Mulgrave and Russell Rivers (Cairns)  Johnstone River (Innisfail)  Lake Koombooloomba (Tully)  Ross River including Aplin, Gleeson and Black Weirs (Townsville)  Barratta Creek lagoons (Brandon)  Sheepstation Creek Lagoons (Brandon)  Charters Tower Weir on the Burdekin River (Charters Towers)  Lake Dalrymple (Ayr)  Burdekin River (Collinsville)  Clare Weir on Burdekin River (Ayr)  Lake Proserpine (Proserpine)  Lake Eungella (Mackay)  Lake Teemburra (Mackay)

1 From FFSAQ website www.ffsaq.ausfish.com.au

page 11  Hedlow Creek and Serpentine Lagoon (Rockhampton)  Alligator Creek (Rockhampton)  Fitzroy River at Laurel Bank (Rockhampton)  Mount Morgan Reservoir (Mount Morgan)  Baralaba Weir on Dawson River (Baralaba)  Moura Weir on Dawson River (Moura)  Theodore Weir on Dawson River (Theodore)  Glebe Weir on Dawson River (Taroom)  Bedford Weir on Mackenzie River (Blackwater)  Lake Theresa (Clermont)  Lake Callide (Biloela)  Wilmott Lagoon (Mount Larcom)  Lake Awoonga (Gladstone)  Lake Callemondah (Gladstone)  Railway Dam or Duck Pond (Gladstone) Mary/Burnett  Lake Monduran (Gin Gin)  Lake Gregory (Bundaberg)  Lake Cania (Monto)  Lake Wuruma (Eidsvold)  Lake Barambah (Murgon)  Lake Boondooma (Proston)  Burnett River (Gayndah to Wallaville)  Lake Lenthall (Howard)  Lake Borumba (Imbil)  Lake Baroon (Kenilworth)  Lake MacDonald (Noosa)  Lake Samsonvale (Brisbane)  Pukallus Weir on Cooyar Creek (Yarraman)  Lake Somerset (Esk)  Lake Wivenhoe (Lowood)  Lake Dyer (Lowood)  Lake Cressbrook (Toowoomba)  Mount Crosby Weir on Brisbane River (Ipswich)  Lake Moogerah (Boonah)  Lake Maroon (Rathdowney)  Albert River (Rathdowney)  Lake Hinze (Gold Coast)  Lake Glenlyon (Texas) Murray/Darling  Lake Cooby (Toowoomba)  Oakey Weir on Oakey Creek (Oakey)  Yarramalong Weir on Condamine River (Millmerrin)  Cecil Plains Weir on Condamine River (Cecil Plains)  Lake Coolmunda (Inglewood)  Dogwood Creek (Miles)  Surat Weir (Surat)

page 12 BARRON RIVER TRINITY INLET LAKE TINAROO MULGRAVE RIVER JOHNSTONE RIVER LAKE KOOMBOOLOOMBA LAKE BELMORE ROSS RIVER LAKE BARRATTA CREEK SHEEPSTATION CREEK LAKE FRED JULIUS TRITTON CHARTERS CLARE TOWERS LAKE PROSERPINE CHINAMAN LAKE LAKE LAKE EUNGELLA RESERVOIR DALRYMPLE MOONDARRA LAKE TEEMBURRA

LAKE THERESA HEDLOW CREEK BEDFORD WEIR FITZROY RIVER LAKE CALLEMONDAH BARALABA WEIR LAKE AWOONGA MOURA WEIR LAKE CALLIDE THEODORE WEIR LAKE MONDURAN LAKE CANIA LAKE GREGORY LAKE WURUMA LAKE LENTHALL LAKE BARAMBAH LAKE BOONDOOMA LAKE BAROON LAKE CRESSBROOK LAKE MACDONALD SURAT WEIR LAKE SOMERSET LAKE SAMSONVALE LAKE WIVENHOE LAKE HINZE LAKE COOLMUNDA LAKE MOOGERAH LAKE LAKE LESLIE MAROON

Figure 2: Locations where fish have been tagged in impoundments and waterways 1987-2008

page 13 2. Aims

This is 1 of 3 reports examining fish stocked and tagged in impoundments and waterways of Queensland. The reports are:

 Summary of tagging of stocked fish in impoundments and waterways of Queensland 1987-2007  Winter 2007 fish death events: Impact on stocked fish  Growth, movement and survival of stocked fish from tagging programs in impoundments and waterways of Queensland 1987-2008

The aims of this report are to analyse tagging data from stocked fish from 1987- 2008 in relation to:

 Growth of stocked fish in impoundments and waterways  Movement of stocked fish beyond the impoundment or waterway  Survival of tagged fish released in Batches  Survival of fish in impoundments where low water levels were experienced  Implications for future stocking

3. Methods

3.1 Growth of Stocked Fish

Tag and recapture data from 1984-2008 were analysed to estimate growth for 3 key species. The species were:

 Barramundi (Lates calcarifer)  Australian Bass ( novaemaculata)  Golden Perch (Macquaria ambigua)

Growth rates were calculated using 3 different methods.

a) Annual growth rate

The annual growth rate was calculated as:

AGR = ((TLr – TLt)/ Dr-t)*365

Where

AGR = annual growth rate in millimeters TLr = total length on recapture TLt = total length on tagging Dr-t = time in days between tagging and recapture

Fish with apparent negative growth, where lengths were not recorded and fish that were at liberty for less than 30 days were excluded when calculating growth. Fish with major outlier growth rates were assumed to be erroroneous and excluded.

Linear daily growth rates were calculated and then converted to annual growth rates. Data are only shown for those locations where there were at least 5 recaptures that provided valid growth.

b) Growth variation between batch releases

The growth of some batches of fish released from 2000 onward in a number of impoundments and waterways was described by plotting the length of fish when tagged and recaptured against time. This was used to examine differences in growth between batches.

c) Modelling growth equations

page 14 Growth of fish was assessed using GROTAG which estimates growth parameters from tag and recapture data.

GROTAG uses least squares regression techniques to estimate Linf and K by minimising the difference between predicted and observed lengths at recapture.

GROTAG uses a modification of the von Bertalanffy growth equation described by Francis (1988). This can be described as:

TLr = Linf*(1-exp(-K*(Dr-t)) - (TLt*(1-exp(-K*(Dr-t))

Where

TLr = total length on recapture Linf = asymptotic length K = instantaneous daily growth rate Dr-t = time in days between tagging and recapture

This was then used to calculate the size of fish for each year of age and growth curves were generated from these data.

3.2 Movement of Stocked Fish

Tag and recapture data were analysed for 3 key species that have been stocked to provide information on movement. The species were:

 Barramundi (Lates calcarifer)  Australian Bass (Macquaria novaemaculata)  Golden Perch (Macquaria ambigua)

Movement of fish tagged in impoundments was recorded as:

 Within the impoundment if the recapture was made within the full supply level of the dam or weir.  Outside the impoundment if the recapture was made downstream of the impoundment wall or upstream of the full supply level of the dam or weir.  The distance between the tag an recapture location being the shortest distance by the most direct water route.

Movement of fish tagged in open systems was assessed based on the distance between where the fish was tagged and recaptured. Distance was the shortest distance by the most direct water route.

For a number of impoundments and waterways the average distance moved was calculated and for recaptures outside the impoundment or waterways whether the movement was upstream or downstream.

For a number of impoundments plots were made of distance moved and days between tagging and recapture.

For some locations the movement of fish in relation to flows was examined. The recapture of fish tagged prior to significant flow events was assessed to determine whether fish remained in or moved outside the impoundment or waterway. This was compared to movements during periods of low flow.

page 15 3.3 Survival of Tagged Fish Released in Batches

From 1996 batches of larger fish, mostly Barramundi, were tagged and stocked into a number of impoundments and waterways. This provided the opportunity to monitor these fish over subsequent years.

Survival of stocked fish following release cannot be assessed from tagging data however the recapture rate of tagged stocked fish from the release of different batches of tagged fish can be used as an indicator of relative survival between batches.

The recapture rate was calculated as the percentage of recaptures of individual fish compared with the number of fish released in a batch. Multiple recaptures of the same fish were not included.

Some batch releases in open systems were made at discrete locations and the recapture rate of fish released at different sites was also able to be assessed and compared.

The average length of fish stocked in a batch was compared with the average length of recaptured fish when tagged. This was used to assess whether size at release had an influence on the subsequent recapture of fish.

Recapture rates of Barramundi tagged in a number of Queensland rivers was also included to provide a comparison with natural populations.

3.4 Survival of Fish in Impoundments where Low Water Levels were experienced

Over the period of this report a number of impoundments that were stocked experienced very low water levels of below 10% of full capacity and some as low as 1%. Data on monthly water levels was obtained from the authority that was responsible for the management of the impoundment.

Tag and recapture data were examined to determine the effect of low water levels on tagging and the number of recaptures. Recapture rates may give an indication of fish survival, so the recapture rates before during and after periods of very lo9w water levels were compared.

page 16 4. Growth of Stocked Fish

4.1 Growth of Stocked Barramundi

The following impoundments or waterways had sufficient data to calculate annual growth. Average annual growth rates were also calculated for a number of natural populations. Average annual growth for the Johnstone River included stocked and wild fish tagged. This provided a comparison of growth in a number impoundments and stocked locations to wild populations in river systems.

Gulf of Carpentaria  Weipa Rivers (marine system for comparison)  Norman River (marine system for comparison)  Lake Moondarra  Lake Belmore  Lake Fred Trittion North Queensland  Lake Tinaroo  Barron River  Trinity Inlet  Mulgrave River including Russell River  Johnstone River (stocked and wild fish)  Ross River including Aplin, Gleeson and Black Weirs  Haughton River (marine system for comparison)  Barratta Creek including Sheepstation Creek  Charters Tower Weir on Burdekin River  Clare Weir on Burdekin River  Lake Proserpine Central Queensland  Fitzroy Salt estuary (marine system for comparison)  Fitzroy Fresh including Alligator Creek  Hedlow Creek including Serpentine Lagoon  Moura Weir on Dawson River  Bedford Weir on Mackenzie River  Lake Callide  Lake Awoonga  Lake Callemondah  Railway Dam or Duck Pond Mary/Burnett  Mary River (marine system for comparison)  Lake Lenthall

A summary of annual growth rates is shown in table 1 and figure 3. Growth of natural populations is shown in red in table 1 and figure 3. The lowest growth was for fish in Lake Belmore where the annual average growth rate was 86.3mm, however this was for only 9 fish which were an average length of 790.3mm when tagged and reflect a lower growth rate for larger fish. The highest growth was for fish in Lake Fred Tritton with an annual growth rate of 360.7mm however these were small fish tagged recently at an average of 299.3mm and were mostly recaptured within a few months when growth rates are highest. This is unlikely to be reflective of growth rates over a longer time.

Generally where the growth rates of stocked fish are high this reflects growth of smaller fish over shorter time periods and this needs to be taken into account when making comparisons.

page 17 Growth rates in natural systems are provided for comparison. Fish from the rivers entering Albatross Bay at Weipa had an annual growth rate of 74.0mm and this is low compared with other natural systems. The average annual growth rate of 130.2mm for fish in the Norman River is more typical. Fish from the Haughton River had an annual growth rate of 98.2mm while for the Fitzroy River estuary it was 151.8mm. The Mary River is the southern most population of Barramundi and had an annual growth rate of 144.7mm.

USED AVERAGE AVERAGE AVERAGE AVERAGE FOR DAYS TAG RECAP ANNUAL 95% RECAPS GROWTH OUT LENGTH LENGTH GROWTH CONFIDENCE GULF OF CARPENTARIA WEIPA 550 463 644.6 518.1 618.2 74.0 5.8 NORMAN RIVER 144 108 557.6 558.8 718 130.2 17.2 LAKE MOONDARRA 63 29 977.2 576.8 921.6 174.0 50.6 LAKE BELMORE 11 9 888.3 790.3 952.0 86.3 56.3 LAKE FRED TRITTON 13 12 136.7 299.3 430.4 360.7 66.2 NORTH QUEENSLAND LAKE TINAROO 137 135 611.4 303.0 636.2 223.7 13.6 BARRON RIVER 51 43 467.3 296.6 431.9 128.3 37.7 TRINITY INLET 159 146 658.8 293.7 488.5 122.9 13.2 MULGRAVE RIVER 32 26 663.7 284.2 453.5 87.9 9.8 JOHNSTONE RIVER 633 579 550.8 397.2 517.4 93.2 7.0 ROSS RIVER 405 338 699.5 538.1 717.6 132.6 16.3 HAUGHTON RIVER 167 150 776.2 487.6 661.8 98.2 10.2 BARRATTA CREEK 24 24 744.0 240.0 680.3 234.7 32.5 CHARTERS TOWERS WEIR 5 5 508.6 439.2 640.0 167.9 52.1 CLARE WEIR 53 52 429.7 188.4 537.8 276.2 75.1 LAKE PROSERPINE 6 6 774.8 292.8 659.2 224.9 61.7 CENTRAL QUEENSLAND FITZROY SALT 4585 3198 514.1 435.4 612.2 151.8 3.8 FITZROY FRESH 76 43 1014.9 201.9 735.9 195.6 10.2 HELDOW CREEK 45 41 851.5 449.0 722.3 124.2 10.1 MOURA WEIR 114 96 607.1 229.9 673.7 273.3 9.5 BEDFORD WEIR 34 29 311.0 205.6 445.0 341.6 64.3 LAKE CALLIDE 14 14 704.9 280.1 679.6 217.5 32.6 LAKE AWOONGA 226 212 966.3 240.8 741.5 240.2 13.3 LAKE CALLEMONDAH 42 33 431.6 539.1 711.4 169.2 29.8 RAILWAY DAM 13 9 334.8 479.4 676.1 266.4 75.7 MARY/BURNETT MARY RIVER 362 284 464.6 448.6 600.9 144.7 11.1 LAKE LENTHALL 13 10 490.3 470.5 670.0 150.3 19.1

Table 1: Summary of growth of Barramundi in stocking divisions with natural populations for comparison

page 18 STOCKED BARRAMUNI GROWTH

GULF OF CARPENTARIA

WEIPA

NORMAN RIVER

LAKE MOONDARRA

LAKE BELMORE

LAKE FRED TRITTON

NORTH QUEENSLAND

LAKE TINAROO

BARRON RIVER

TRINITY INLET

MULGRAVE RIVER

JOHNSTONE RIVER

ROSS RIVER

HAUGHTON RIVER

BARRATTA CREEK

CHARTERS TOWERS WEIR

CLARE WEIR

LAKE PROSERPINE

CENTRAL QUEENSLAND

FITZROY SALT

FITZROY FRESH

HELDOW CREEK

MOURA WEIR

BEDFORD WEIR

LAKE CALLIDE

LAKE AWOONGA

LAKE CALLEMONDAH

RAILWAY DAM

MARY/BURNETT

MARY RIVER

LAKE LENTHALL

0 100 200 300 400 500 ANNUAL GROWTH RATE (MM)

Figure 3: Average annual growth rate for stocked Barramundi and natural populations (red) for comparison

page 19 4.2 Growth of Tagged Barramundi Released in Batches

From 1996-2008 there were 59,692 tagged Barramundi released in batches into 25 impoundments and waterways. Of these there have been 991 (1.7%) recaptures with 931 (1.6%) with sufficient data to calculate growth. Table 2 provides a summary of these releases. At some locations for a number of releases there was sufficient data to track the growth of these fish over time.

DATES BATCH AVERAGE RECAPS YEAR RELEASED SIZE LENGTH RECAPS GROWTH GULF OF CARPENTARIA LAKE MOONDARRA 2004 5/6/2004 46 188.9 0 0 LAKE FRED TRITTON 2008 3/08/2008 97 239.6 11 10 NORTH QUEENSLAND TRINITY INLET 2002 14/12/2002 3010 286.8 102 99 TRINITY INLET 2004 21-28/2/2004 2381 293.2 61 56 TRINITY INLET 2005 17/04/2005 1246 277.6 23 23 TRINITY INLET 2007 2/11/2007 1543 275.1 10 8 MULGRAVE RIVER 2004 4/07/2004 589 285.9 14 13 MULGRAVE RIVER 2005 17/04/2005 997 278.3 8 7 MULGRAVE RIVER 2007 2/11/2007 1511 272.2 2 2 CENTENARY LAKE 2005 25/10/2005 226 321.8 1 0 LAKE TINAROO 2003 13/10/2003 1138 276.3 48 47 LAKE TINAROO 2004 5/6-7/8/2004 4099 291.9 1 1 2004- 16/10/2004- LAKE TINAROO 05 27/2/2005 5980 310.6 92 91 LAKE TINAROO 2005 15/5-7/8/2005 1239 295.1 0 0 BLACK WEIR 2000 13/10/2000 109 269.3 19 18 BLACK WEIR 2007 20/01/2007 510 326.3 34 33 BLACK WEIR 2007 10-28/11/2007 542 301.0 33 33 APLIN WEIR 2007 18/03/2007 489 350.6 30 30 EAST BARRATTA CREEK 2006 18/03/2006 250 215 4 4 WEST BARRATTA CREEK 2006 21/11/2006 531 200 0 0 WOODHOUSE LAGOON 2005 19/02/2005 232 210 2 2 DICKS LAGOON 2007 6/03/2007 152 160 0 0 DICKS LAGOON 2007 28/4/2007 50 325 0 0 CHURCH LAGOON 2006 11/03/2006 809 205 3 3 PEGORARO LAGOON 2005 19/02/2005 54 210 3 3 GORIZIA LAGOON 2005 19/02/2005 150 210 14 14 GLADYS LAGOON 2005 19/02/2005 50 210 1 1 CLARE WEIR 2003 30/10/2003 146 144.0 4 4 CLARE WEIR 2005 12/03/2005 781 187 21 21 CLARE WEIR 2005 26/11/2005 1162 185 19 18 CLARE WEIR 2006 18/11/2006 1039 200 4 4 CLARE WEIR 2007 19/09/2007 337 240 1 1 LAKE DALRYMPLE 2005 5/02/2005 515 175 3 3 LAKE DALRYMPLE 2007 17/02/2007 683 300 0 0 LAKE DALRYMPLE 2007 27/10/2007 1550 280 0 0 LAKE PROSERPINE 2004 21/03/2004 135 214.6 3 3 LAKE PROSERPINE 2006 26/05/2006 114 250.5 0 0 LAKE PROSERPINE 2006 27/10/2006 207 247.1 1 1 LAKE PROSERPINE 2007 10/02/2007 111 337.8 0 0

page 20 DATES BATCH AVERAGE RECAPS YEAR RELEASED SIZE LENGTH RECAPS GROWTH CENTRAL QUEENSLAND LAKE AWOONGA 1996 20/1/1996 201 302 17 17 LAKE AWOONGA 1997 27/5/1997 232 128 0 0 LAKE AWOONGA 1997 3-27/6/1997 1316 119 0 0 LAKE AWOONGA 1998 5-27/2/1998 610 182 20 20 LAKE AWOONGA 1998 12-31/3/1998 740 221 34 34 LAKE AWOONGA 1998 7-30/4/1998 1043 234 27 27 LAKE AWOONGA 1998 7-21/5/1998 674 244 6 6 LAKE AWOONGA 2000 9-23/2/2000 2968 174 87 82 LAKE AWOONGA 2000 1-3/3/2000 773 174 10 9 LAKE AWOONGA 2000 31/5-7/6/2000 5019 155 1 1 ALLIGATOR CREEK 2005 5/02/2005 1198 197.0 65 43 FITZROY LAUREL BANK 2006 11/02/2006 3317 202.6 11 9 LAKE CALLIDE 2005 28/01/2005 600 239.1 12 12 MOURA WEIR 2005 2/02/2005 600 197.5 32 27 MOURA WEIR 2006 10/02/2006 600 206.7 61 61 BEDFORD WEIR 2005 8/02/2005 600 196.8 19 16 BEDFORD WEIR 2006 1-24/02/2006 3541 211.5 15 14 LAKE THERESA 2007 10/11/2007 850 - 2 0 TOTAL 59692 991 931

Table 2: Summary of tagged Barramundi released in batches from 1996-2008

1000

900

800

700 )

M 600 M (

H 500 T G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI TINAROO BATCH RELEASE 2003 0 0 500 1000 1500 2000 DAYS OUT 1000

900

800

700 )

M 600 M (

T 500 H G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI TINAROO BATCH RELEASE 2004-05 0 0 500 1000 1500 2000 DAYS OUT

Figure 4: Growth of Barramundi released in batches into Lake Tinaroo in 2003 and 2004-05

page 21 Figure 4 shows the growth of two batches of fish released into Lake Tinaroo in 2003 and 2004-05 which showed similar growth rates over time.

1000 900

800 700 )

M 600 M (

H 500 T G

N 400 E L 300 200

100 GROWTH OF BARRAMUNDI TRINITY INLET BATCH RELEASE 2002 0 0 500 1000 1500 2000 2500

1000 DAYS OUT 900 800

) 700 M

M 600 (

H 500 T G

N 400 E L 300 200 GROWTH OF BARRAMUNDI TRINITY INLET AND BARRON RIVER 100 BATCH RELEASE 2004 0 0 500 1000 1500 2000 2500 1000 DAYS OUT 900 800 700 ) M

M 600 (

H 500 T G

N 400 E L 300 200 GROWTH OF BARRAMUNDI TRINITY INLET AND BARRON RIVER 100 BATCH RELEASE 2005 0 0 500 1000 1500 2000 2500 DAYS OUT

Figure 5: Growth of Barramundi released in batches into Trinity Inlet and the Barron River from 2002 to 2005

Figure 5 shows the growth of fish compared with days out for 3 batch releases in Trinity Inlet and the Barron River from 2002 to 2008. Data from these releases has been combined as there was no significant difference in the growth rates for each

page 22 system (table 1 and figure 3). The growth rate for each batch release was also not significantly different.

1000

900

800 700 )

M 600 M (

T 500 H G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI BLACK WEIR RELEASE 2000 0 0 500 1000 1500 2000 2500 3000 DAYS OUT 1000

900

800

700 )

M 600 M (

H 500 T G

N 400 E L 300

200 GROWTH OF BARRAMUNDI BLACK AND APLIN WEIR BATCH RELEASE 100 2007 0 0 500 1000 1500 2000 2500 3000 DAYS OUT

Figure 6: Growth of Barramundi released in batches in Black and Aplin Weirs on the Ross River in 2000 and 2007

Figure 6 shows the growth of 2 batches of fish released in Black and Aplin Weirs on the Ross River. The batch released in 2000 was the first batch released and provides the longest timeline of growth. By comparison the growth rate for fish released in 2007 appears to be significantly higher.

Figure 7 shows the growth of a batch of fish released in Alligator Creek (Fitzroy River) in 2005. The lack of recaptures early reflects the lack of fishing effort in the area with recaptures being made later when the fish moved down into the Fitzroy River estuary (see section 5.1) and were mostly caught by commercial fishers.

Figure 8 shows the growth of 2 batches of fish released into Moura Weir on the Dawson River in 2005 and 2006. Many of the recaptures from both batches were fish that were recovered in a fish kill in winter 2007.2 Growth rates of fish in both releases are similar.

2 See Fish death events: Impact on stocked fish: Winter 2007

page 23 1000

900

800

700 )

M 600 M (

T 500 H G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI ALLIGATOR CREEK BATCH RELEASE 2005 0 0 500 1000 1500 2000 DAYS OUT

Figure 7: Growth of Barramundi batch released into Alligator Creek (Fitzroy River) in 2005

1000

900

800

700 )

M 600 M (

H 500 T G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI MOURA WEIR BATCH RELEASE 2005 0 0 500 1000 1500 2000 DAYS OUT 1000

900

800

700 )

M 600 M (

H 500 T G

N 400 E L 300

200

100 GROWTH OF BARRAMUNDI MOURA WEIR BATCH RELEASE 2006 0 0 500 1000 1500 2000 DAYS OUT

Figure 8: Growth of Barramundi batch released into Moura Weir in 2005 and 2006

page 24 1200

1000

800 ) M M (

H 600 T G N E L 400

200

GROWTH OF AWOONGA BATCH RELEASE 1998 0 0 500 1000 1500 2000 2500 3000 3500 4000 DAYS OUT 1400

1200

1000 ) M

M 800 (

H T G

N 600 E L

400

200 GROWTH OF AWOONGA BATCH RELEASE 2000 0 0 500 1000 1500 2000 2500 3000 DAYS OUT

Figure 9: Growth of Barramundi released in batches into Lake Awoonga in 1998 and 2000

Figure 9 shows the growth of batches of fish released in summer and autumn in 1998 and 2000 into Lake Awoonga. Fish released in 1998 were each month from February to May and were individually measured at an averaged 223mm. Fish released in 2000 were released in February-March and were not individually measured. The average length of the batches was recorded with an overall average estimated at 174mm.

Three batch releases of fish have had recaptures of fish that have now been at liberty for over 7 years (2,555 days). These were batch releases in Lake Awoonga in 1998 and 2000 and a release in Black Weir in 2000. Fish in Lake Awoonga were generally over 1000mm long after 5 years (1,825 days) while fish released in Black Weir were generally only 800-900mm after that time.

For Lake Tinaroo fish from the batch release in 2002 have been recaptured up to almost 5 years (1,812 days) after release. There has only been 1 fish recaptured after that time and it was 900mm long.

page 25 4.3 Growth Curves for Barramundi

Growth curves were generated for a number of locations where there was sufficient data, however for most locations a lack of longer term recaptures beyond 5 years results in lower confidence in the projection of the curves.

Growth curves are shown for a number of locations in Central Queensland and compared with the growth curve for the Fitzroy River estuary where there were good long term recaptures.

Figure 10 shows growth curves for 6 freshwater locations where fish were stocked compared with the Fitzroy estuary (saltwater). This indicates that for 5 of the locations the growth rates in the early years were significantly higher for fish in freshwater. Only fish stocked in Hedlow Creek showed a similar growth to fish in the Fitzroy estuary.

1600 BARRAMUNDI GROWTH CURVES FITZROY 1400

1200 ) m

m 1000 (

h t

g 800 n e L

Fitzroy Salt l

a 600

t Moura o

T Bedford 400 Hedlow Fitzroy Fresh 200

0 0 2 4 6 8 10 12 14 16 Age (yrs)

1400 BARRAMUNDI GROWTH CURVES GLADSTONE 1200

) 1000 m m ( 800 h t g n e

L 600

l Fitzroy Salt a t o T 400 Callemondah Awoonga 200

0 0 2 4 6 8 10 12 14 16 Age (yrs)

Figure 10: Growth curves for freshwater stocked locations compared to the Fitzroy River estuary

page 26 4.4 Discussion on Barramundi Growth

Caution is required in the interpretation of growth rates since those locations where growth rates were for smaller fish over a shorter time period would be expected to be higher than for larger fish and longer term recaptures. Growth rates of smaller fish are significantly higher than for larger fish as shown in the growth curves however the data do provide some comparison of growth. Also for some locations the growth rate was calculated from a very small sample and further data are likely to change the growth rates.

Growth of Barramundi was variable however a number of observations can be made. Growth rates for fish in freshwater were significantly higher than those in saltwater. This is likely to be the result of a better food supply, less competition from other predatory species and fewer predators on Barramundi. This is particularly significant as Barramundi tend to use freshwater for their first few years and then return to the saltwater.

Growth rates for fish stocked in wet tropic locations are generally lower than for other locations. Growth rates for the natural population of fish at Weipa are the lowest recorded for any location and supports these fish being a genetically distinct strain of Barramundi.3

Growth rates for the same location can also vary over time. The batch releases of Barramundi at particular locations show similar growth rates over different years. However for Black and Aplin Weirs there appears to be a higher growth rate for fish released in 2007 compared with those released in 2000. More recapture data for fish released in 2007 is needed to confirm this. This could be related to different environmental conditions between the years or to the genetics of the broodstock used.

4.5 Growth of Stocked Australian Bass

The following impoundments and waterways had sufficient data to calculate annual growth. Average annual growth rate was also calculated for the natural population of Australian Bass in the Noosa River. This provided a comparison of growth in a number of impoundments and waterways to a wild population in river.

Mary/Burnett  Lake Barambah  Lake Boondooma  Lake Gregory  Lake Borumba South East Queensland  Noosa River (river system for comparison)  Lake Samsonvale  Lake Somerset  Lake Moogerah  Lake Maroon  Lake Cressbrook

A summary of annual growth rates is shown in table 3 and figure 11. Growth of the natural population is shown in red in table 3 and figure 11. The lowest growth rate was for the Noosa River where the annual growth rates was 14.3mm while the lowest rate for stocked fish was for Lake Cressbrook where the rate was 15.2mm. The highest growth rate was for fish in Lake Somerset where the rate was 34.4mm. There was no significant difference in the growth rate for fish in Mary/Burnett impoundments.

3 Barramundi discoveries may change management John Salini and James Shaklee Australian Fisheries 1987

page 27 USED AVERAGE AVERAGE AVERAGE AVERAGE 95% FOR DAYS TAG RECAP ANNUAL CONFIDENCE LOCATION RECAPS GROWTH OUT LENGTH LENGTH GROWTH LIMIT MARY/BURNETT LAKE BARAMBAH 128 90 500.8 371.9 396.4 28.0 8.6 LAKE BOONDOOMA 843 711 1074.9 315.8 378.6 27.6 2.5 LAKE GREGORY 18 14 426.6 399.3 413.2 29.5 15.8 LAKE BORUMBA 25 15 329.5 342.7 365.5 25.1 11.8 SOUTH EAST QUEENSLAND NOOSA RIVER 150 110 1142.4 284.5 320.1 14.3 3.1 LAKE SAMSONVALE 47 36 369.1 432.4 445.4 21.6 8.5 LAKE SOMERSET 611 567 1497.1 311.1 411.9 34.4 2.6 LAKE MOOGERAH 726 663 1071.2 317.1 389.9 30.5 1.9 LAKE MAROON 41 41 1357.3 271.8 368.8 33.2 6.2 LAKE CRESSBROOK 477 395 1300.8 314.5 354.3 15.2 1.8

Table 3: Summary of recaptures and annual growth rates for stocked Australian Bass and for Noosa River fish

STOCKED AUSTRALIAN BASS ANNUAL GROWTH

MARY/BURNETT

LAKE BARAMBAH

LAKE BOONDOOMA

LAKE GREGORY

LAKE BORUMBA

SOUTH EAST QUEENSLAND

NOOSA RIVER

LAKE SAMSONVALE

LAKE SOMERSET

LAKE MOOGERAH

LAKE MAROON

LAKE CRESSBROOK

0 10 20 30 40 50 GROWTH (MM/YR)

Figure 11: Summary of annual growth rates for stocked Australian Bass and Noosa River fish

page 28 4.6 Growth Curve for Australian Bass

Growth curves were generated for a number of locations where there was sufficient data. For these locations there were sufficient long term recaptures to provide longer term growth (table 4). Growth curves are shown in figure 12. The curves show the faster growth rate for Australian Bass in the impoundments compared to those in a natural river.

Max days at liberty LOCATION (years in bracket) LAKE SOMERSET 4793 (13.1) LAKE BOONDOOMA 4625 (12.7) LAKE CRESSBROOK 5045 (13.8) LAKE MOOGERAH 3666 (10.0) NOOSA RIVER 4004 (11.0)

Table 4: Maximum time at liberty for recaptured Australian Bass

500

450 BASS GROWTH CURVES

400

350 ) m m

( 300

h t

g 250 n e L

l 200 a t

o Somerset T 150 Boondooma Cressbrook 100 Moogerah 50 Noosa

0 0 2 4 6 8 10 12 14 16 Age (yrs)

Figure 12: Growth curves for Australian Bass in a number of impoundments and Noosa River

4.7 Discussion on Australian Bass Growth

Australian Bass are a slow growing species that attains a maximum size of around 600mm however that growth is variable depending on location. While there is only 1 natural system to compare with for growth it appear likely that Australian Bass grow faster in impoundments compared with natural rivers, or at least the Noosa River.

There was no significant difference in the growth rates for Australian Bass in impoundments in the Mary/Burnett impoundments however there were significant differences for impoundments in south east Queensland. Lake Cressbrook had the lowest growth rate of any impoundment and it is uncertain as to the reason(s) for this. The lake is smaller than Boondooma and Somerset but larger than Moogerah. As the lake is at a higher altitude than the other impoundments it could be related to overall cooler water temperatures.

page 29 4.8 Growth of Stocked Golden Perch

The following impoundments and waterways had sufficient data to calculate annual growth. Average annual growth rate was also calculated for Golden Perch in the Dawson River which has a mixed population of wild and stocked fish. This provided a comparison of growth in a number of impoundments and a population in a river.

Central Queensland  Dawson River (river system for comparison) Mary/Burnett  Lake Barambah  Lake Boondooma South East Queensland  Lake Somerset Murray/Darling  Lake Leslie

USED AVERAGE AVERAGE AVERAGE AVERAGE FOR DAYS TAG RECAP ANNUAL 95% LOCATION RECAPS GROWTH OUT LENGTH LENGTH GROWTH CONFIDENCE CENTRAL QUEENSLAND DAWSON RIVER 41 29 489.6 368.6 390.4 30.8 11.2 MARY/BURNETT LAKE BOONDOOMA 532 383 816.5 351.3 404.9 33.2 3.3 LAKE BARAMBAH 15 9 341.6 438.3 462.8 32.8 19.0 SOUTH EAST QUEENSLAND LAKE SOMERSET 268 203 881.0 388.6 437.6 37.3 5.7 MURRAY/DARLING LAKE LESLIE 115 73 738.3 342.4 407.4 60.5 13.9

Table 5: Summary of recaptures and annual growth rates for stocked Golden Perch

STOCKED GOLDEN PERCH ANNUAL GROWTH

CENTRAL QUEENSLAND

DAWSON RIVER

MARY/BURNETT

LAKE BOONDOOMA

LAKE BARAMBAH

SOUTH EAST QUEENSLAND

LAKE SOMERSET

MURRAY/DARLING

LAKE LESLIE

0 10 20 30 40 50 60 70 80 GROWTH (MM/YR)

Figure 13: Summary of annual growth rates for stocked Golden Perch and for Dawson River fish

page 30 A summary of annual growth is shown in table 5 and figure 13 with the growth of the natural/stocked population in the Dawson River shown in red. The lowest growth rate was for fish in the Dawson River with an annual growth rate of 30.8mm however this rate was not significantly different to those in Mary/Burnett impoundments. The highest growth rate was for fish in Lake Leslie.

4.9 Growth Curves for Golden Perch

Growth curves were generated for 3 impoundments where there was sufficient data as shown in figure 14. For these locations there were sufficient long term recaptures to provide longer term growth (table 6).

Max days at liberty LOCATION (years in brackets) LAKE LESLIE 3344 (9.2) LAKE SOMERSET 5039 (13.8) LAKE BOONDOOMA 3959 (10.8)

Table 6: Maximum time at liberty for recaptured Golden Perch

500

450

400

) 350 GOLDEN PERCH

m GROWTH CURVES m

( 300

h t

g 250 n Boondooma e L

l 200

a Somerset t o T 150 Leslie 100

50

0 0 2 4 6 8 10 12 14 16 Age (yrs)

Figure 14: Growth curves for Golden Perch in 3 impoundments

4.10 Discussion on Growth of Golden Perch

The only location where there was a significant difference in the growth rate of Golden Perch was Lake Leslie. The reason for such a difference is unknown.

page 31 5. Movement of Stocked Fish

5.1 Movement of Stocked Barramundi

There were 46 impoundments and waterways where stocked Barramundi have been tagged. Table 7 provides a summary of the number of fish tagged in each impoundment, the number of recaptures and the number of recaptures outside the impoundment or waterway.

OUTSIDE IMPOUNDMENT OR WATERWAY TAGGED RECAPS IMPOUNDMENT GULF OF CARPENTARIA LAKE JULIUS 1 0 0 LAKE MOONDARRA 580 63 3 LAKE BELMORE 141 10 0 CHINAMAN RESERVOIR 31 1 0 LAKE FRED TRITTON 97 11 0 NORTH QUEENSLAND LAKE TINAROO 12617 155 0 BARRON RIVER 2084 51 3 TRINITY INLET 7218 159 7 RUSSELL/MULGRAVE RIVER 5051 31 4 JOHNSTONE RIVER 5578 633 13 LAKE KOOMBOOLOOMBA 4 0 0 BLACK WEIR (ROSS RIVER) 1531 169 52 GLEESON WEIR (ROSS RIVER) 38 4 1 APLIN WEIR (ROSS RIVER) 1083 236 75 EAST BARRATTA CREEK 250 4 0 WOODHOUSE LAGOON (BARRATTA CREEK) 232 0 0 SHEEPSTATION CREEK 50 0 0 DICKS LAGOON (SHEEPSTATION CREEK) 152 0 0 PEGORARO LAGOON (SHEEPSTATION CREEK) 54 3 1 CHURCH LAGOON (SHEEPSTATION CREEK) 809 3 0 GORIZIA LAGOON (SHEEPSTATION CREEK) 159 14 1 CHARTERS TOWERS WEIR (BURDEKIN RIVER) 49 5 2 GLADYS LAGOON 50 1 0 CLARE WEIR (BURDEKIN RIVER) 2684 30 28 LAKE DALRYMPLE 3298 3 3 LAKE PROSERPINE 601 6 0 LAKE EUNGELLA 35 5 0 LAKE TEEMBURRA 152 3 0 CENTRAL QUEENSLAND SERPENTINE LAGOON (FITZROY RIVER) 111 14 14 HEDLOW CREEK (FITZROY RIVER) 374 30 19 ALLIGATOR CREEK (FITZROY RIVER) 1198 65 64 LAUREL BANK (FITZROY RIVER) 3317 11 11 BARALABA WEIR (DAWSON RIVER) 78 1 1 MOURA WEIR (DAWSON RIVER) 1310 114 8 THEODORE WEIR (DAWSON RIVER) 21 0 0 BEDFORD WEIR (MACKENZIE RIVER) 4141 34 33 LAKE THERESA 870 5 2 LAKE CALLIDE 645 14 0 WILMOTT LAGOON (CALLIOPE RIVER) 26 2 1 LAKE AWOONGA 14501 225 0

page 32 OUTSIDE IMPOUNDMENT OR WATERWAY TAGGED RECAPS IMPOUNDMENT CENTRAL QUEENSLAND LAKE CALLEMONDAH 535 105 59 RAILWAY DAM (GLADSTONE) 113 13 4 MARY/BURNETT LAKE MONDURAN 262 3 0 LAKE WURUMA 14 0 0 LAKE BOONDOOMA 1 0 0 LAKE LENTHALL 96 13 0 TOTAL 72242 2250 403

Table 7: Summary of Barramundi movements outside impoundment or waterway

IMPOUNDMENT BARRON TRINITY MULGRAVE JOHNSTONE NUMBER OF RECAPTURES 51 159 31 633 MOVEMENT KNOWN 51 153 31 611 AVERAGE DAYS OUT 415.3 604.7 556.6 508.1 AVERAGE DISTANCE MOVED 3.7 4.7 11.4 3.6 OUTSIDE IMPOUNDMENT 3 7 4 13 MOVED DOWNSTREAM 3 7 4 13 MOVED UPSTREAM 0 0 0 0 GREATEST DISTANCE MOVED 20 72 55 115 IMPOUNDMENT APLIN BLACK CLARE HAUGHTON NUMBER OF RECAPTURES 236 169 50 167 MOVEMENT KNOWN 236 169 49 143 AVERAGE DAYS OUT 533.1 720.3 423.9 757.1 AVERAGE DISTANCE MOVED 2.6 3.2 23.8 10.3 OUTSIDE IMPOUNDMENT 75 52 48 14 MOVED DOWNSTREAM 75 52 45 14 MOVED UPSTREAM 0 0 3 0 GREATEST DISTANCE MOVED 130 80 105 105 IMPOUNDMENT HEDLOW SERPENTINE ALLIGATOR LAUREL BANK NUMBER OF RECAPTURES 30 14 65 11 MOVEMENT KNOWN 30 14 65 11 AVERAGE DAYS OUT 891.6 904.2 1090.8 698.5 AVERAGE DISTANCE MOVED 92.5 142.9 68.9 30.4 OUTSIDE IMPOUNDMENT 19 14 64 11 MOVED DOWNSTREAM 19 14 64 11 MOVED UPSTREAM 0 0 0 0 GREATEST DISTANCE MOVED 275 240 120 48 IMPOUNDMENT BEDFORD MOURA CALLEMONDAH FITZROY NUMBER OF RECAPTURES 34 114 105 2727 MOVEMENT KNOWN 34 106 103 2542 AVERAGE DAYS OUT 326.0 550.7 604.5 540.9 AVERAGE DISTANCE MOVED 47.3 30.1 7.2 11.1 OUTSIDE IMPOUNDMENT 33 8 59 135 MOVED DOWNSTREAM 33 8 59 126 MOVED UPSTREAM 0 0 0 9 GREATEST DISTANCE MOVED 520 450 36 650

Table 8: Summary of Barramundi movement (km) outside of impoundments or waterways

page 33 The overall number of recaptures was 2,250 which is a recapture rate of 3.1% for these impoundments and waterways. Of these 403 (17.9%) were recaptured outside the impoundment or waterway they were tagged in. There were 24 locations where fish were recaptured outside the impoundment or waterway which is 52% of locations where Barramundi were tagged (table 7).

Table 8 provides a summary of movement in a number of impoundments and the Haughton and Fitzroy River for comparison with wild populations. The average distance moved ranged from 2.6km for Aplin Weir to 142.9km for Serpentine Lagoon. For fish that moved outside the impoundment or waterway only 3 fish from Clare Weir moved upstream with all other fish moving downstream.

For Lake Moondarra and Lake Dalrymple there were 3 fish recaptured outside of each impoundment. Both lakes have high dam walls and these fish survived going over the wall. At both locations dead Barramundi have been recorded following water flowing over the spillway but some fish do survive.

100 BARRAMUNDI MOVEMENT TRINITY INLET AND BARRON RIVER 90

80

70 ) M

K 60 (

E

C 50 N A T

S 40 I D 30

20

10

0 0 500 1000 1500 2000 2500 DAYS OUT

Figure 15: Movement of Barramundi stocked in Trinity Inlet and Barron River

Figure 15 shows the movement of stocked fish in Trinity Inlet and Barron River. Data for these 2 waterways has been combined as the systems are adjacent and fish movement is similar in each system. The average distance fish in Trinity Inlet moved is 3.7km while for the Barron River it was 4.7km. Two fish released in Trinity Inlet were recaptured in the Barron River. One fish released in Trinity Inlet was recaptured 72km south in the Russell River.

Figure 16 shows the movement of stocked fish in Mulgrave and Russell Rivers. The average distance moved was 11.4km and the maximum distance moved was 55km. Four fish were recaptured outside the rivers with all being caught to the south. One fish was recaptured at Bramston Beach while 3 were recaptured in the Johnstone River.

page 34 100 BARRAMUNDI MOVEMENTS MULGRAVE AND RUSSELL RIVERS 90

80

70 ) M

K 60 (

E

C 50 N A T

S 40 I D 30

20

10

0 0 200 400 600 800 1000 1200 1400 1600 DAYS OUT

Figure 16: Movement of Barramundi stocked in Mulgrave and Russell Rivers

140 BARRAMUNDI MOVEMENT JOHNSTONE RIVER 120

100 ) M K (

80 E C N A

T 60 S I D 40

20

0 0 500 1000 1500 2000 2500 3000 3500 4000 DAYS OUT

Figure 17: Movement of Barramundi stocked in Johnstone River

Figure 17 shows the movement of fish in the Johnstone River. The average distance moved was 3.6km and the maximum distance moved was 115km. Thirteen fish were recaptured outside the Johnstone River with 5 fish recaptured to the south and 8 recaptured to the north.

Figure 18 shows where Barramundi tagged in the Johnstone River have been recaptured outside the system. This extends from the Barron River in the north to the Hull River in the south.

page 35 RECAPTURES

AREA FISH TAGGED

Figure 18: Locations where Barramundi tagged in the Johnstone River have been recaptured elsewhere

The Ross River at Townsville has 3 weirs on it between the and the estuary. The weirs are Black, Gleeson and Aplin. Each weir pool has been stocked with Barramundi with most fish being stocked in Black and Aplin weir pools. When the weirs overflow fish move between weir pools and down into Ross River estuary and beyond.

LOCATION ELSE- TAGGED TAGGED RECAPS BLACK GLEESON APLIN ROSS WHERE BLACK WEIR 2024 173 120 27 13 11 2 GLEESON WEIR 38 4 0 3 1 0 0 APLIN WEIR 1083 237 0 0 160 70 7 TOTALS 3145 414 120 30 174 81 9

Table 9: Summary of Barramundi tagged and recaptured in Ross River weirs

Table 9 provides a summary of the Barramundi tagged in Ross River weir pools and recaptured. A total of 3,145 fish were tagged with 414 recaptures which is a recapture rate of 14.7%.

Of the recaptures 131 (31.6%) were from outside the weir pool they were tagged in. For fish tagged in the 3 weir pools no fish were caught above the weir pool they were tagged in, 68.4% of fish were caught in the same pool as tagged, 9.9% were recaptured in a downstream weir pool while 21.7% were recaptured below all weir pools in the Ross River estuary and beyond (figure 19).

page 36 80.0%

ROSS WEIRS RECAPTURES 70.0%

60.0%

50.0%

40.0%

30.0%

20.0%

10.0%

0.0% ABOVE WEIR SAME WEIR BELOW WEIR BELOW ALL WEIRS

Figure 19: Where Barramundi tagged in Ross River weir pools were recaptured

1400

Fish Length 1200 Monthly Rainfall )

m 1000 m (

l l a f n i 800 a r

d n a

t 600 h g n e l

h 400 s i F

200

0 27-Nov-93 23-Aug-96 20-May-99 13-Feb-02 09-Nov-04 06-Aug-07

Figure 20: Stocked Barramundi in Ross River weir pools and monthly rainfall from 1994-2008

Figure 20 shows stocked Barramundi tagged in the Ross River weir pools from 1994- 2008 compared with monthly rainfall for Townsville4. No river flow data is available for the Ross River so rainfall has been used to indicate flow. It is likely that water will flow over the weirs when there is over 200mm of rain in a month. Based on this it is likely that the weirs have overflowed each year, mostly in January or February and this would allow fish to leave the weir pool they were in.

Flows such as the one in February 2007 over Aplin Weir (figure 21) and Black Weir (figure 22) allow fish to move downstream to the Ross River estuary and beyond.

However the weir walls provide an effective barrier to upstream movement even under high flow conditions as no fish have been recaptured in an upstream weir pool.

4 Rainfall from Bureau of Meteorology website for Townsville Airport 032040

page 37 Figure 21: Flow over Aplin Weir in February 2007

Figure 22: Flow over Black Weir in February 2007

page 38 Figure 23 shows the movement of stocked fish tagged in the Ross River weirs. The average distance moved was 2.6km for fish tagged in Black Weir and 3.2km for those tagged in Aplin Weir. The maximum distance moved was 130km. Of the 81 fish recaptured in the Ross River estuary 61 (75.3%) were recaptured immediately below Aplin Weir. Nine fish were recaptured outside the Ross River with 3 fish recaptured to the south and 6 recaptured to the north.

Figure 24 shows where Barramundi tagged in the Ross River weirs that have been recaptured outside the system. This extends from the Balgal Beach in the north to Groper Creek in the south.

140 BARRAMUNDI MOVEMENT ROSS RIVER WEIRS 120

100 ) M K ( 80 E C N A

T 60 S I D 40

20

0 0 500 1000 1500 2000 2500 3000 3500 4000 DAYS OUT

Figure 23: Movement of Barramundi stocked in Ross River weir pools

RECAPTURES

BLACK WEIR APLIN WEIR GLEESON WEIR AREA FISH TAGGED

ROSS RIVER DAM

Figure 24: Locations where stocked Barramundi tagged in Ross River weir pools have been recaptured outside the river

page 39 120 BARRAMUNDI MOVEMENT HAUGHTON RIVER

100

) 80 M K (

E

C 60 N A T S I

D 40

20

0 0 500 1000 1500 2000 2500 3000 DAYS OUT

Figure 25: Movement of wild Barramundi tagged in the Haughton River

Figure 25 shows the movement of wild fish tagged in the Haughton River for comparison. The average distance moved was 10.3km and the maximum distance moved was 105km. Of the 143 fish recaptured 14 (9.8%) were recaptured outside the Haughton River with 10 fish recaptured to the south down to Groper Creek and 5 recaptured to the north to Ross River.

120 BARRAMUNDI MOVEMENT CLARE WEIR

100

80 ) M K (

E

C 60 N A T S I D 40

20

0 0 200 400 600 800 1000 1200 1400 DAYS OUT

Figure 26: Movement of stocked Barramundi in Clare Weir

Figure 26 shows the movement of stocked fish tagged in Clare Weir. The average distance moved was 23.4km and the maximum distance moved was 105km. Of the 48 fish recaptured 45 (93.8%) were recaptured downstream with 27 (56.3%) recaptured in the Clare weir fishway. Fish tagged in Clare Weir are the only ones to have recorded an upstream movement with 3 fish recaptured above the weir pool. One fish was recaptured 105km upstream at the base of the wall. This fish had to negotiate its way past the Gorge Weir to reach the dam wall. This is only

page 40 the second recording for Barramundi where fish have moved past an upstream weir barrier. The other was in the Fitzroy River following the 1991 flood. Two fish were recaptured downstream outside the Burdekin River. These were fish recaptured in Hellhole Creek to the north. Figure 27 shows where tagged stocked fish released in Clare Weir have been recaptured outside the weir pool.

CLARE WEIR AREA TAGGED FISH RELEASED

RECAPTURES

GORGE WEIR

BURDEKIN DAM WALL

Figure 27: Movement of tagged Barramundi stocked in Clare Weir

300

250

200 ) M K (

E

C 150 N A T S I D 100

BARRAMUNDI MOVEMENT HEDLOW CREEK AND SERPENTINE LAGOON 50

0 0 500 1000 1500 2000 2500 DAYS OUT Figure 28: Movement of tagged stocked Barramundi in Hedlow Creek and Serpentine Lagoon

page 41 Figure 28 shows the movement of stocked fish tagged in Hedlow Creek and Serpentine Lagoon. The average distance moved was 92.5km for fish in Hedlow Creek and 149.2km for fish in Serpentine Lagoon. The maximum distance moved was 275km. Of the fish tagged in Hedlow Creek 11 fish were recaptured in the same area, 14 were recaptured downstream in the Fitzroy River estuary and 5 were recaptured outside the Fitzroy River. Of the fish tagged in Serpentine Lagoon none were recaptured in the lagoon with 11 recaptured downstream in the Fitzroy River estuary and 2 recaptured outside the Fitzroy River. The movement of these fish to the Fitzroy estuary and beyond was associated with flooding in February 2003 and January-February 2008.

500 BARRAMUNDI MOVEMENT MOURA WEIR 450

400

350 ) M

K 300 (

E

C 250 N A T

S 200 I D 150

100

50

0 0 200 400 600 800 1000 1200 1400 1600 DAYS OUT

Figure 29: Movement of tagged stocked Barramundi in Moura Weir

Figure 29 shows the movement of stocked fish in Moura Weir. A total of 98 fish were recaptured in the weir with 78 being recovered in the weir following a fish kill in winter 2007.5 The other 8 fish were recaptured over 400km downstream in the Fitzroy River estuary with 1 fish being recaptured outside the river to the north in Coorooman Creek 450km from where it was tagged. Fish recaptured in the estuary passed over 5 weir walls in their movement downstream.

Figure 30 shows the movement of stocked fish in Bedford Weir. Of the 34 fish recaptured only 1 has been recaptured in the weir pool. There were 29 fish recaptured immediately below the weir and to 7km downstream. The remaining 3 fish were recaptured over 500km downstream in the Fitzroy River estuary having passed over 5 weir walls.

The movement of fish from both Moura and Bedford weirs were associated with flooding in February 2003 and January-February 2008 which allowed the fish to negotiate downstream weirs.

5 See Fish death events: Impact on stocked fish: Winter 2007

page 42 600 BARRAMUNDI MOVEMENT BEDFORD WEIR

500

400 ) M K (

E

C 300 N A T S I D 200

100

0 0 200 400 600 800 1000 1200 DAYS OUT

Figure 30: Movement of tagged stocked Barramundi in Bedford Weir

140 BARRAMUNDI MOVEMENT ALLIGATOR CREEK AND LAUREL BANK FITZROY RIVER 120

100 ) M K (

80 E C N A

T 60 S I D 40

20

0 0 200 400 600 800 1000 1200 1400 DAYS OUT

Figure 31: Movement of stocked tagged Barramundi in Alligator Creek and at Laurel Bank on the Fitzroy River

Figure 31 shows the movement of tagged stocked fish in Alligator Creek and at Laurel Bank on the Fitzroy River. Of the 76 fish recaptured only 1 has been recaptured in the area released. The remaining 75 fish have all been caught downstream in the Fitzroy River estuary below the Fitzroy Barrage.

Figure 32 shows the movement of wild fish tagged in the Fitzroy River estuary which has been included for comparison. Of the 2,727 recaptures there were 137 (5.0%) recaptured outside the estuary. Of these 66 were caught adjacent to the river in the adjoining creeks of the estuary out to Cape Capricorn. A total of 30 fish were recaptured up to 650km to the north and 32 recaptured up to 350km to the south.

page 43 A total of 9 fish moved upstream. Of these 5 were fish that had been caught at the Rockhampton Barrage and released upstream above the Barrage. The remaining 4 fish were all tagged before the 1991 flood and recaptured after the flood up to 240km upstream. These are the only recaptures of wild fish that have been recaptured upstream of a barrier from where they were tagged.

700 BARRAMUNDI MOVEMENT FITZROY RIVER ESTUARY 600

500 ) M K (

400 E C N A

T 300 S I D 200

100

0 0 1000 2000 3000 4000 5000 DAYS OUT

Figure 32: Movement of wild fish tagged in the Fitzroy River estuary

Alligator M Serpentine Lagoon r Creek e a v c i k R e YEPPOON e n zi WEIRS R n z iv e ie e k r c R a Hedlow Creek M iv e y r o r Laurel Bank z t i Bedford Weir F BARRAGE ROCKHAMPTON

BLACKWATER Recaptures outside Fitzroy River DUARINGA Recaptures in Fitzroy River estuary

Tagged Barram undi

r

e

v i 0 40 80

R

n

o s WEIR kilometres w a BARALABA

D

BILOELA

MOURA Moura Weir

Figure 33: Movement of tagged Barramundi from stocking locations to the Fitzroy River estuary and beyond

Figure 33 shows the movement of tagged stocked Barramundi from locations where they were stocked to the Fitzroy River estuary and beyond. All these movements were associated with flooding in February 2003 and January-February 2008.

page 44 In the Fitzroy River estuary there were 245 recaptures of fish that were at liberty for less than 1 year that moved over 5km and were able to move both upstream and downstream. There were 116 fish up to 580mm with 83 (71.6%) that moved upstream and 33 (28.4%) that moved downstream. There were 129 fish over 580mm with 20 (15.5%) that moved upstream and 109 (84.5%) that moved downstream. Of 9 fish that moved upstream of the Barrage all were less than 580mm when tagged and 8 of these were recaptured within 1 year. This indicates that juvenile fish primarily move upstream while adult fish primarily move downstream.

6000000 1200 FLOW Fish Length 5000000 1000 Hedlow and Serpentine fish tagged

) 4000000 800 L h t M ( g

n w e o L l

f

3000000 600 d y e l g h t g n a o T

M 2000000 400

Laurel Bank stocking Alligator 1000000 200 stocking

0 0 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ------l l l l l l l l l n n n n n n n n n u u u u u u u u u a a a a a a a a a J J J J J J J J J J J J J J J J J J

Figure 34: Comparison of river flows at Riverslea on the Fitzroy River and Barramundi stocked and tagged at Hedlow Creek, Serpentine Lagoon, Alligator Creek and Laurel Bank on the Fitzroy River Figure 34 shows a composite of fish released and later tagged in Hedlow Creek and Serpentine Lagoon, batch releases of tagged Barramundi in Alligator Creek and at Laurel Bank on the Fitzroy River compared with river flows in the Fitzroy River at Riverslea.6

There were 346 fish tagged in Hedlow Creek and Serpentine Lagoon up to February 2003 prior to the flow in the river that month. Of these 2 were recaptured in the same area prior to that flow. Following that flow a further 33 fish have been recaptured. One in the same area as tagged, 2 had moved from Hedlow Creek into the adjacent Lake Mary and 28 were recaptured in the Fitzroy River estuary and beyond with 1 fish recaptured in the Boyne River 240km from where tagged.

From February 2003 to January 2008 there were no flows of sufficient size to connect Hedlow Creek to the Fitzroy River. In that time a further 148 fish were tagged in Hedlow Creek and Serpentine Lagoon. Of these 6 were recaptured from May 2004 to August 2007 and all were recaptured in the same area as tagged. Following the flow in January-February 2008 a further 5 were recaptured all downstream in the Fitzroy River estuary and beyond. One fish was recaptured 275km to the south in Worthington Creek at Turkey Beach.

There have been no fish tagged in Hedlow Creek or Serpentine Lagoon since August 2007 suggesting that most of the fish may have left the creek on the January- February 2008 flow.

6 River flow data from Natural Resources and Water website and from Rockhampton office for Riverslea Gauging Station 130003B

page 45 There was a batch release of 1,198 tagged Barramundi in Alligator Creek in February 2005. Only 1 fish was recaptured in the same area as tagged and that was in August 2005. The remaining 64 recaptures have been downstream in the Fitzroy River estuary below the Barrage and up to 120km from where released. There was a small flow in the river of around 97,000ML in January 2007. Follow that flow and prior to the flow in January 2008 there were 3 fish recaptured down in the estuary. The remaining 61 recaptures were all caught in the estuary after the season opened on 1 February 2008 with 56 fish recaptured by commercial fishers.

There was also a batch release of 3,317 tagged Barramundi in February 2006 in the Fitzroy River at Laurel Bank 17km upstream from the Barrage. No fish from this release have been recaptured in the same area as tagged with 11 fish having been recaptured downstream in the estuary below the Barrage. One fish was recaptured in the estuary not long after the release in May 2006. There was a small flow in the river shortly after the release and the fish probably moved downstream on that flow.

There were 2 fish recaptured in the 2007 Rocky Barra Bounty fishing competition in October 2007 following the flow in January 2007. The remaining 8 fish were all caught in the estuary following the flow in January-February 2008 with 6 fish recaptured by commercial fishers.

One fish from the batch release at Laurel Bank was recaptured in Frogmore Lagoon after the 2008 flood (figure 35). The lagoon is adjacent to the freshwater section of Gavial Creek. This was the first recording of a recapture of a fish that moved downstream to the estuary then moved up another creek back into freshwater.

TAGGED

RECAPTURED

Figure 35: Stocked tagged Barramundi released at Laurel Bank on the Fitzroy River and recaptured in Frogmore Lagoon

page 46 40 BARRAMUNDI MOVEMENT LAKE CALLEMONDAH 35

30 )

M 25 K (

E

C 20 N A T S

I 15 D

10

5

0 0 500 1000 1500 2000 2500 DAYS OUT

Figure 36: Movement of stocked fish tagged in Lake Callemondah

LAKE CALLEMONDAH

RECAPTURES

Figure 37: Movement of stocked Barramundi tagged in Lake Callemondah

Figure 36 shows the movement of stocked fish tagged in Lake Callemondah. Of the 103 recaptures there were 59 (57.3%) recaptured outside the lake. Lake Callemondah is unique in impoundments stocked with Barramundi in that fish moving from the lake enter directly into the Auckland Creek estuary. Figure 37 shows the locations where fish have been recaptured outside the lake. The furthest distance a fish has moved from the lake is 36km.

page 47 1200 700 Barramundi left lake on Barramundi left lake on flow from this rainfall flow from this rainfall 600 1000 Fish Length Monthly rainfall

500 800 ) m ) m m 400 (

m h (

t l l

g 600 a n f e n l i

300 a h R s i F 400 200

200 100

0 0 01-Dec-99 30-Nov-00 30-Nov-01 30-Nov-02 30-Nov-03 29-Nov-04 29-Nov-05 29-Nov-06 29-Nov-07 28-Nov-08 Date

Figure 38: Comparison of monthly rainfall at Gladstone and Barramundi stocked and tagged in Lake Callemondah

Figure 39: Lake Callemondah dam wall in a low flow event

Figure 38 provides a comparison of the stocked and tagged Barramundi in Lake Callemondah and rainfall at Gladstone Airport.7 Of 29 recaptures prior to February 2003 only 1 was from outside the lake. From February 2003 to April 2005 there were a further 45 recaptures with 42 of these being from outside the lake. The flow in February 2003 allowed fish to leave the lake.

From May 2005 to January 2008 there were a further 19 recaptures with 12 from the lake and 7 from outside. Of the fish recaptured in the lake only 1 was a fish tagged prior to February 2003. Of the 7 caught elsewhere 6 were fish tagged prior to February 2003. Following the flow in February 2008 there were a further 9 recaptures which were all from outside the lake. The flow in February 2008 again allowed fish to leave the lake. These large flows allowed many fish to leave the lake.

7 Rainfall from Bureau of Meteorology website for Gladstone Airport 039326

page 48 Only 2 recaptures have been made where fish left the lake on smaller flows. Figure 39 shows the Callemondah dam wall during a low flow event.

5.2 Discussion on Barramundi Movement

Barramundi movement is primarily associated with flooding or high flows that allow fish to migrate. That movement is generally upstream for juvenile fish and then is primarily downstream for fish that are adult over legal size.

Of the 403 stocked Barramundi that were recaptured outside the impoundment they were tagged all moved downstream except for 3 fish released into Clare weir. There are a number of reasons for this.

Generally there is less suitable habitat for Barramundi upstream from the impoundments where the fish were tagged and as a result there is also less fishing effort. So while some fish may have moved upstream there was less chance that they would be detected.

Also with elevated growth rates in impoundments fish reach legal size more quickly, often within 2 years. If there are no substantial flows in that time then when the flow occurs the fish are more likely to move downstream.

Barriers to upstream movement pose particular problems to upstream migration but are not a significant impediment to downstream migration, particularly if they are low structures. Of fish tagged in the Ross River weir pools none have been recaptured above the next upstream barrier while 131 have been recaptured below the weir and 13 fish managed to go over all 3 weirs.

In the Fitzroy River system only 4 wild Barramundi have been recorded upstream of the Barrage having been tagged below the Barrage. All fish were tagged prior to the 1991 flood and recaptured within 1 year of the flood. No stocked fish have been recaptured above an upstream barrier in the Fitzroy River system.

Fish stocked in Moura and Bedford Weirs had to negotiate 5 weirs on their way down to the Fitzroy River estuary. Fish from Serpentine Lagoon and Hedlow Creek had to negotiate the Barrage to get to the estuary.

Even for lakes with high walls there is a downstream movement of fish when the dams overflow. While many fish are killed 3 fish survived going over the Moondarra dam spillway and 3 fish survived going over the Burdekin dam spillway.

Many of the locations where Barramundi have been stocked along the east coast are open or marine systems which allow fish to move more freely than in impoundments. Tagging has provided data on the subsequent distribution of these fish. Most fish have been recaptured within 20km of where they were released and the leakage from the system to other systems is low at less than 5%. Therefore any impacts on the genetics of wild stocks through stocked fish taking part in spawning are likely to be confined to the system in which the fish were stocked.

The exception is the Fitzroy River where fish from locations over 500km upstream were able to migrate to the estuary when suitable flows occur. Following the 2008 flood in January-February there were 99 tagged fish recaptured in the Fitzroy River by commercial and recreational fishers from February to June 2008. Of these 70 (70.7%) were stocked fish from upstream locations. This indicates that stocked fish could have made up a significant proportion of fish in the estuary at the time and could take part in future spawning wild stocks. However provided hatcheries follow they established protocols in relation to use of brood stock any impacts are likely to be low but are uncertain and worthy of study.

page 49 5.3 Movement of Stocked Australian Bass

There were 18 impoundments where Australian Bass have been tagged. Table 10 provides a summary of the number of fish tagged in each impoundment, the number of recaptures and the number of recaptures from outside the impoundment.

OUTSIDE IMPOUNDMENT TAGGED RECAPS IMPOUNDMENT MARY/BURNETT LAKE CANIA 197 10 0 LAKE WURUMA 234 10 0 LAKE BARAMBAH 1899 127 0 LAKE BOONDOOMA 9020 855 4 LAKE MONDURAN 26 2 0 LAKE GREGORY 534 19 0 LAKE LENTHALL 42 2 0 LAKE BORUMBA 709 25 0 LAKE BAROON 514 9 3 LAKE MACDONALD 312 4 0 SOUTH EAST QUEENSLAND LAKE CRESSBROOK 4262 482 0 PUKALLUS WEIR (COOYAR CREEK) 18 1 0 LAKE SOMERSET 9067 610 26 LAKE WIVENHOE 144 8 2 LAKE MOOGERAH 6177 726 0 LAKE MAROON 331 41 0 LAKE SAMSONVALE 2381 47 0 LAKE HINZE 132 2 1 TOTAL 35999 2980 36

Table 10: Summary of Australian Bass movements outside impoundments

The overall number of recaptures was 2,980 which is a recapture rate of 8.3% for these impoundments. Of these 1.2% were recaptured outside the impoundment they were tagged in. There were 5 impoundments where tagged fish were recaptured outside the impoundment, these were Lake Hinze, Somerset, Wivenhoe, Baroon and Boondooma.

Table 11 provides a summary of movement in a number of impoundments. As most movements are confined to the impoundment the average distance moved is related to the surface area of the impoundment and ranged from 1.1km in Lake Moogerah to 6.9km in Lake Somerset. Data on movement in the Noosa River was also included to provide a comparison with a natural population.

page 50 MOOGERAH SOMERSET CRESSBROOK NUMBER OF RECAPTURES 726 610 482 MOVEMENT KNOWN 624 556 388 AVERAGE DAYS OUT 1038.2 1475.1 1213.2 MAXIMUM SURFACE AREA KM2 8.27 39.67 5.17 AVERAGE DISTANCE MOVED KM 1.1 6.9 1.3 MOVED OUTSIDE IMPOUNDMENT 0 26 0 MOVED DOWNSTREAM 0 24 0 MOVED UPSTREAM 0 2 0 GREATEST DISTANCE MOVED 5 290 7 NOOSA BARAMBAH BOONDOOMA NUMBER OF RECAPTURES 153 127 855 MOVEMENT KNOWN 129 106 765 AVERAGE DAYS OUT 875.9 433.5 1000.8 MAXIMUM SURFACE AREA KM2 21.50 18.15 AVERAGE DISTANCE MOVED KM 4.1 2.2 3.9 MOVED OUTSIDE IMPOUNDMENT NA 0 4 MOVED DOWNSTREAM 29 0 3 MOVED UPSTREAM 41 0 1 GREATEST DISTANCE MOVED 33 14 135

Table 11: Summary of Australian Bass movements

Figure 40 shows the movement of fish tagged in Lake Somerset while figure 35 shows where fish tagged in Somerset were recaptured outside the lake. Maximum distance between tag and recapture in the lake was 22km.

There were 26 fish recaptured outside the lake with 2 being recaptured upstream in Kilcoy Creek. One fish was recaptured just below Kilcoy Creek weir which is the next upstream barrier that prevents upstream migration.

The other 24 fish were recaptured downstream having survived going over the Somerset wall. Fifteen (15) of these fish were caught below the wall and in Lake Wivenhoe. A further 4 fish were caught at the bottom of the Wivenhoe spillway having survived going over both dam walls. A further 4 fish were recaptured in the Brisbane River from below Wivenhoe to Colleges Crossing with 2 fish being recaptured below Crosby Weir. These fish survived going over 3 walls. The fish that moved the furthest was caught in Saltwater Creek on the Gold Coast which was 290km downstream from where it was tagged (not shown on figure 41). This was the only Australian Bass recaptured in saltwater.

page 51 350 MOVEMENT OF AUSTRALIAN BASS TAGGED IN LAKE SOMERSET 300

250 ) M K (

200 E C N A

T 150 S I D 100

50

0 0 1000 2000 3000 4000 5000 6000 7000 DAYS OUT

Figure 40: Distance moved compared with days out for Australian Bass in Lake Somerset

LAKE SOMERSET

SOMERSET DAMWALL

LAKE WIVENHOE

WIVENHOE DAMWALL

MOUNT CROSBY WEIR

Figure 41: Australian Bass tagged in Lake Somerset and recaptured outside the lake

page 52 160 MOVEMENT OF AUSTRALIAN BASS TAGGED IN LAKE BOONDOOMA 140

120 ) M

K 100 (

E C 80 N A T S

I 60 D

40

20

0 0 1000 2000 3000 4000 5000 DAYS OUT

Figure 42: Distance moved compared with days out for Australian Bass in Lake Boodooma

DOWNSTREAM 135KM IN CLAUDE WHARTON WEIR

BOONDOOMA DAM WALL

LAKE BOONDOOMA

GORDONBROOK WEIR WALL

Figure 43: Australian Bass tagged in Lake Boondooma and recaptured outside the lake

Figure 42 shows the movement of fish tagged in Lake Boondooma. There were 4 fish recaptured outside the lake. Three (3) fish were both caught downstream in the Boyne River. Two (2) fish were caught below the dam wall 3-4km downstream while one fish was recaptured 135km downstream in Claude Wharton Weir on the Boyne River. Figure 43 shows where fish tagged in Boondooma were recaptured outside the lake.

page 53 50 MOVEMENT OF AUSTRALIAN BASS TAGGED IN NOOSA RIVER 45

40

35 ) M K

( 30

E

C 25 N A T

S 20 I D 15

10

5

0 0 500 1000 1500 2000 2500 3000 3500 DAYS OUT

Figure 44: Distance moved compared with days out for Australian Bass in Noosa River

FISH TAGGED IN FRESHWATER REACHES OF NOOSA RIVER

LAKE COOTHARABA

LAKE COOROIBAH

NOOSA

Figure 45: Recaptures of tagged Australian Bass outside the tagging area in the Noosa River

Figure 44 shows the movement of Australian Bass in the Noosa River which is a natural population in a river that is not impacted by barriers to fish movement. All fish were tagged in the freshwater reaches of the river upstream from Lake Cootharaba. Fish moved both up and down the river (table 11) above the lake. Nine (9) fish were recaptured downstream in Lake Cootharaba, 1 was recaptured in Lake Cooroibah and 1 in the lower reaches of the Noosa River (downstream 33km from where it was tagged).

page 54 5.4 Discussion on Australian Bass Movement

Movement of Australian Bass was mostly confined to the impoundment in which they were stocked. Movement outside the impoundments was associated with flows. Upstream movement was likely to be associated with inflows to the impoundment and downstream movement with overflows of the impoundment via the spillway or wall.

A greater number of movements were recorded downstream compared with upstream. There may be a number of reasons for this. It is likely that the level of fishing effort above impoundments is significantly lower than effort downstream of the impoundments and therefore the likelihood of recaptures being made upstream is lower than downstream.

Also adult Australian Bass are likely to move downstream related to the need to move to the estuary for spawning. It is also possible in high flow events that fish are accidentally washed downstream.

The low numbers of Australian Bass recorded as having moved outside the impoundment where stocked is also likely to be the result of prolonged dry and drought periods during the years following tagging. This would have limited the opportunity for fish to move outside the impoundment. It is likely in wetter years where high flows and overflows from impoundments occur that a greater number of fish would move outside their impoundment.

5.5 Movement of Stocked Golden Perch

There were 17 impoundments and 1 river where Golden Perch have been tagged. Table 12 provides a summary of the number of fish tagged in each impoundment, the number of recaptures and the number of recaptures from outside the impoundment.

The overall number of recaptures was 1,022 which is a recapture rate of 9.4% for these impoundments. Of these 1.2% were recaptured outside the impoundment they were tagged in. There were 2 impoundments where tagged fish were recaptured outside the impoundment, these were Lake Somerset and Boondooma.

Table 13 provides a summary of movement in a number of impoundments. As most movements are confined to the impoundment the average distance moved is related to the surface area of the impoundment and ranged from 1.4km in Lake Cania to 4.1km in Lake Somerset. Data on movement in the Dawson River was also included to provide a comparison with movement in a river system.

Figure 46 shows the movement of fish tagged in Lake Somerset. There were 10 fish recaptured outside the lake with 5 being recaptured upstream in Sheepstation and Kilcoy Creeks. The other 5 fish were recaptured downstream having survived going over the Somerset wall. Four of these fish were caught below the Somerset dam wall and in Lake Wivenhoe. One fish was caught 115km downstream at Colleges Crossing on the Brisbane River so survived going over both Somerset and walls and then over Mount Crosby Weir. Figure 47 shows where fish tagged in Somerset were recaptured outside the lake.

page 55 OUTSIDE IMPOUNDMENT TAGGED RECAPS IMPOUNDMENT CENTRAL QUEENSLAND DAWSON RIVER 1127 31 NA MOUNT MORGAN RESERVOIR 10 10 0 MARY/BURNETT LAKE CANIA 108 22 0 LAKE WURUMA 13 0 0 LAKE BARAMBAH 323 13 0 LAKE BOONDOOMA 4113 532 2 LAKE BORUMBA 28 1 0 LAKE MACDONALD 15 3 0 SOUTH EAST QUEENSLAND PUKALLUS WEIR (COOYAR CREEK) 35 1 0 LAKE CRESSBROOK 138 13 0 LAKE SOMERSET 3770 268 10 LAKE SAMSONVALE 49 1 0 LAKE MOOGERAH 108 9 0 LAKE MAROON 9 3 0 LAKE HINZE 2 0 0 LAKE GLENLYON 3 0 0 MURRAY/DARLING LAKE COOBY 10 0 0 LAKE LESLIE 988 115 0 TOTAL 10849 1022 12

Table 12: Summary of Golden Perch tagged and recaptured and movements outside impoundments

LESLIE SOMERSET BOONDOOMA NUMBER OF RECAPTURES 115 268 532 MOVEMENT KNOWN 58 229 468 AVERAGE DAYS OUT 708.3 799.5 667.1 MAXIMUM SURFACE AREA KM2 12.88 39.67 18.15 AVERAGE DISTANCE MOVED KM 2.1 4.1 2.3 MOVED OUTSIDE IMPOUNDMENT 0 10 2 MOVED DOWNSTREAM 0 5 0 MOVED UPSTREAM 0 5 2 GREATEST DISTANCE MOVED 7 115 28 BARAMBAH CANIA DAWSON NUMBER OF RECAPTURES 13 22 47 MOVEMENT KNOWN 12 16 47 AVERAGE DAYS OUT 259.3 901.4 386.6 MAXIMUM SURFACE AREA KM2 21.50 7.60 NA AVERAGE DISTANCE MOVED KM 1.6 1.4 19.4 MOVED OUTSIDE IMPOUNDMENT 0 0 NA MOVED DOWNSTREAM 0 0 1 MOVED UPSTREAM 0 0 17 GREATEST DISTANCE MOVED 6 4 125

Table 13: Summary of Golden Perch movements

page 56 140 MOVEMENT OF GOLDEN PERCH TAGGED IN LAKE SOMERSET 120 ) M

K 100 (

D E

V 80 O M

E

C 60 N A T

S 40 I D 20

0 0 1000 2000 3000 4000 5000 6000 DAYS OUT

Figure 46: Distance moved compared with days out for Golden Perch in Lake Somerset

LAKE SOMERSET

SOMERSET DAMWALL

LAKE WIVENHOE

WIVENHOE DAMWALL

MOUNT CROSBY WEIR

Figure 47: Golden Perch tagged in Lake Somerset and recaptured outside the lake

page 57 100 MOVEMENT OF GOLDEN PERCH TAGGED IN LAKE BOONDOOMA 90

80 )

M 70 K (

D 60 E V O

M 50

E C

N 40 A T S

I 30 D

20

10

0 0 1000 2000 3000 4000 5000 DAYS OUT

Figure 48: Distance moved compared with days out for Golden Perch in Lake Boondooma

BOONDOOMA DAM WALL

LAKE BOONDOOMA

GORDONBROOK WEIR WALL

Figure 49: Golden Perch tagged in Lake Boondooma and recaptured outside the lake

Figure 48 shows the movement of fish tagged in Lake Boondooma. There were 2 fish recaptured outside the lake. These fish were both caught upstream in the Stuart River with one fish caught 28km upstream below Gordonbrook Weir which is the next barrier upstream from Lake Boondooma. Figure 49 shows where fish tagged in Boondooma were recaptured outside the lake.

page 58 140 MOVEMENT OF GOLDEN PERCH IN DAWSON RIVER 120 ) M

K 100 (

D E

V 80 O M

E

C 60 N A T S

I 40 D

20

0 0 500 1000 1500 2000 2500 DAYS OUT

Figure 50: Distance moved compared with days out for Golden Perch in Dawson River

BARALABA WEIR

MOURA WEIR

D

a w

s o n THEODORE WEIR

R

i v e r

ORANGE CREEK WEIR

GLEBE WEIR

TAGGED

RECAPTURED

Figure 51: Movement of tagged Golden Perch in the Dawson River

Figure 50 shows the movement of Golden Perch tagged in the Dawson River. The average distance moved was 19.4km. Of the fish that moved 1 moved downstream 20km while 17 moved upstream. Eight (8) of the fish tagged in a weir pool were caught upstream at the base of the next barrier which prevented any further movement upstream (figure 51). One (1) fish tagged in Glebe Weir near Taroom was recaptured 125km upstream in Juandan Creek near Wandoan. There are no further barriers to movement above Glebe Weir.

page 59 5.6 Discussion on Golden Perch Movement

Movement of Golden Perch was mostly confined to the impoundment in which they were stocked. Movement outside the impoundments was associated with flows. Upstream movement was likely to be associated with inflows to the impoundment and downstream movement with overflows of the impoundment via the spillway or wall.

A greater number of movements were recorded upstream compared with downstream although the numbers of movements outside impoundments were low. In river systems Golden Perch tend to move upstream to access spawning locations and then downstream following spawning. Spawning is also associated with flows and this is reflected in the movements in the Dawson River.

It is also possible in high flow events that fish are accidentally washed downstream and that would account for some downstream movement.

The low numbers of Golden Perch recorded as having moved outside the impoundment where stocked is also likely to be the result of prolonged dry and drought periods during the years following tagging. This would have limited the opportunity for fish to move outside the impoundment. It is likely in wetter years where high flows and overflows from impoundments occur that a greater number of fish would move outside their impoundment.

page 60 6. Survival of Tagged Fish Released in Batches

6.1 Batch Releases of Barramundi

From 1996 to 2008 there were batch releases of tagged Barramundi into 25 impoundments or waterways. Details of releases are in section 5.1

In August 2008 there was a batch release of tagged fish into Lake Fred Tritton. Table 14 shows the number of tagged fish stocked and the number of recaptures. A total of 97 fish were released with 11 (11.3%) recaptured. The average size of fish stocked was 240mm and the average length at tagging of fish that were recaptured was 264mm.

Tag Length Date Stocked Av Length of Recap Recaptured % Recap 3/08/2008 97 240 264 11 11.3%

Table 14: Barramundi tagged and stocked in batches and recaptured in Lake Fred Tritton

From October 2003 to August 2005 there were 9 releases of batches of tagged fish into Lake Tinaroo. Table 15 shows the number of tagged fish stocked and the number of recaptures of fish from each batch. A total of 12,456 were released for 141 (1.1%) recaptures. Figure 52 shows the recapture rate for fish stocked in each batch release.

Tag Length Date Stocked Av Length of Recap Recaptured % Recap 13/10/2003 1138 276 278 47 4.1% 5-6/06/2004 2243 295 295 1 0.0% 7/08/2004 1856 288 0 0.0% 16/10/2004 1996 287 288 20 1.0% 6/12/2004 100 310 315 2 2.0% 19/12/2004 2026 306 313 41 2.0% 27/02/2005 1858 341 349 30 1.6% 15/05/2005 1094 293 0 0.0% 7/08/2005 145 311 0 0.0% Totals 12456 301 141 1.1%

Table 15: Barramundi tagged and stocked in batches and recaptured in Lake Tinaroo

The highest recapture rate was for fish in the initial release in October 2003 with 4.1% recaptured. The recapture rate for fish stocked in December 2005 was 2.0% for both releases even through one release was only a small number of fish.

For winter releases in June 2004 and August 2004 there has only been 1 recapture with a 0.0% rate. For winter releases in May 2005 and August 2005 there have not been any recaptures with a recapture rate of 0.0%.

The average size of fish at release over all batches was 301mm and ranged from 276mm in October 2003 to 311mm in August 2005. For recaptures the average length at tagging was not significantly different from the average size of fish released.

It should be noted that recaptures are still being made from these releases and recapture rates may change in the future, particularly for the more recent releases.

page 61 2500 4.5% LAKE TINAROO Stocked 4.0% % Recap 2000 3.5%

3.0% D D E

1500 E K R C 2.5% U O T T P S 2.0% A C H E S 1000 I R F 1.5%

500 1.0%

0.5%

0 0.0% 3 4 4 4 4 4 5 5 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 / / / / / / / / / 6 8 2 8 0 0 2 2 5 1 0 0 1 1 1 0 0 0 / / / / / / / / / 3 6 7 6 6 9 7 5 7 - 1 1 1 2 1 5

Figure 52: Recapture rates of batches of tagged Barramundi stocked into Lake Tinaroo

From December 2002 to October 2008 there were 13 releases of batches of tagged fish stocked in the Cairns area as shown in table 16. These releases were into natural systems rather than impoundments and were released into:

 Trinity Inlet  Barron River  Mulgrave River  Russell River  Centenary Lake

Av Tag Length % Date Location Stocked Length of Recap Recaptured Recap 14/12/2002 Trinity 3009 287 295 98 3.3% 21-28/2/2004 Trinity/Barron 2480 293 297 66 2.7% 4/07/2004 Mulgrave/Russell 589 286 283 13 2.2% 17/04/2005 Trinity/Barron 1246 278 284 20 1.6% 17/04/2005 Mulgrave/Russell 997 278 283 8 0.8% 25/10/2005 Centenary Lake 226 322 325 1 0.4% 2/11/2007 Mulgrave/Russell 1511 272 280 2 0.1% 2/11/2007 Trinity/Barron 1543 275 278 10 0.6% 2-3/2/2008 Trinity/Barron 1123 307 316 14 1.2% 3/02/2008 Mulgrave/Russell 1099 304 309 7 0.6% 10/07/2008 Mulgrave/Russell 855 287 0 0.0% 25/10/2008 Mulgrave/Russell 951 2 0.2% 25/10/2008 Trinity/Barron 1224 5 0.4% Totals 16853 290 246 1.5%

Table 16: Barramundi tagged and stocked in batches in the Cairns area

page 62 A total of 16,853 fish have been stocked for 246 (1.5%) recaptured. Figure 53 shows the recapture rate for fish stocked in each batch release.

The highest recapture rate was for fish in the initial release in Trinity Inlet in 2002 with 3.3% recaptured. The average length of tagged fish released was 290mm with a range of 272mm in November 2007 to 322mm in October 2005. For recaptures the average length at tagging was not significantly different from the average size of fish released.

It should be noted that recaptures are still being made from these releases and recapture rates may change in the future, particularly for the more recent releases.

3500 3.5%

TRINITY INLET/BARRON RIVER (GREEN) 3000 MULGRAVE/RUSSELL RIVERS (RED) 3.0%

2500 2.5% D D E E R K U

C 2000 2.0% T O P T A S C E

H 1500 1.5% R S

I F % 1000 1.0%

500 0.5%

0 0.0% 2 4 4 5 5 5 7 7 8 8 8 8 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 2 2 2 2 2 2 2 2 2 2 2 2 2 1 / / / / / / / / / / / / / 2 2 2 7 4 4 0 1 1 2 2 7 0 0 / / 1 0 0 0 1 1 1 0 0 1 1 / 8 / / / / / / 3 / / / / - 4 2 4 7 7 5 2 2 3 0 5 5 2 1 1 1 2 1 2 2

Figure 53: Recapture rates of batches of tagged Barramundi stocked in the Cairns area

For Trinity Inlet and Barron River there were discrete release sites where fish were released in December 2002 and February 2004. Figures 54 and 55 show the recapture rates for locations where fish were release. The overall recapture rate for the 2002 release was 3.3% and for 2004 was 2.6%. Recaptures are still being made from these releases so that recapture rates may increase in the future.

Recaptures at all sites over both releases are low so caution is needed in interpreting the results.

page 63 900 5.0% TRINITY INLET RELEASE SITES 2002 800 4.5% 4.0% 700 Stocked % Recap 3.5% D

D 600 E E R

K 3.0% U C 500 T O P

T 2.5% A S 400 C E H

2.0% R S

I F

300 % 1.5%

200 1.0%

100 0.5%

0 0.0% k n k k k k a e n e e k e k e a e e e e m r e r r r b e a e C C r C C d

r

n C i t s e s C e l l h h h R i n t i C g i i H P r m W S

Figure 54: Recapture rates for Barramundi released at different site in Trinity Inlet in December 2002

450 4.5% TRINITY INLET AND BARRON RIVER 2004 400 4.0%

350 3.5% Stocked D

D 300 3.0% E E % Recap R K U C 250 2.5% T O P T A S 200 2.0% C E H R S

I

F 150 1.5% %

100 1.0%

50 0.5%

0 0.0% s r r k r n k k k i k e e e t a e n e e k e k t k v v k a e a e e i i ) e e e a ) m r e e r r r b e R R 8 e m a e 8 e C C r C w C r d r 1 r o t n 1 n n C l i t s e C s C I C e h l M o o a l ( h h h R ( i T r r n t i S r r C g i i H P a a r m B B W S

Figure 55: Recapture rates for Barramundi released at different sites in Trinity Inlet and Barron River in February 2004 From October 2000 to November 2007 there were 5 releases of batches of tagged fish stocked in the weirs on the Ross River as shown in table 17. Figure 56 shows the recapture rate of fish stocked in each batch. A total of 1,139 fish were stocked with 87 (7.6%) recaptures. The highest recapture rate was 16.5% for fish in the initial release in October 2000.

The average length of fish stocked was 311mm. For recaptures the average length at tagging was not significantly different from the average size of fish released.

page 64 Av Tag Length Date Location Stocked Length of Recaps Recaptured % Recap 13/10/2000 Black Weir 109 269 281 18 16.5% 20/01/2007 Black Weir 510 326 326 33 6.5% 18/03/2007 Aplin Weir 489 351 359 31 6.3% 10/11/2007 Black Weir 520 305 308 36 6.9% 28/11/2007 Gleeson Weir 21 207 0 0.0% Totals 1649 321 118 7.2%

Table 17: Barramundi tagged and stocked in batches and recaptures in Black Weir

600 18.0% ROSS RIVER WEIRS Stocked 16.0% 500 % Recap 14.0%

400 12.0% D D E E R K U C 10.0% T O P

T 300 A S 8.0% C E H R S

I F

200 6.0% %

4.0% 100 2.0%

0 0.0% 0 7 7 7 7 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 / / / / / 0 1 3 1 1 1 0 0 1 1 / / / / / 3 0 8 0 8 1 2 1 1 2

Figure 56: Recapture rates of batches of tagged Barramundi stocked in Ross River weirs

From February 2005 to October 2007 there were 3 releases of tagged fish stocked in Lake Dalrymple as shown in table 18. A total of 2,748 fish have been stocked for 3 (0.1%) recaptures. All recaptures were for fish that survived going over the dam and were recaptured downstream in the Burdekin River.

In table 18 for fish released (*) the length of individual fish were not recorded and the length was shown as the average length for all fish in the batch.

Av Tag Length of % Date Stocked Length Recaps Recaptured Recap 5/02/2005 515 175* 3 0.6% 17/02/2007 683 300* 0 0.0% 27/10/2007 1550 280* 0 0.0% Totals 2748 311 3 0.1%

Table 18: Barramundi tagged and stocked in batches and recaptured in Lake Dalrymple

page 65 From October 2003 to September 2007 there were 5 releases of tagged fish stocked into Clare Weir as shown in table 19. A total of 3,515 fish have been stocked for 49 (1.4%) recaptures. In table 19 for fish released (*) the lengths of individual fish were not recorded and the length was shown as the average length for all fish in the batch. Figure 57 shows the recapture rate for fish stocked in each batch release.

Tag Length of Date Stocked Av Length Recap Recaptured % Recap 30/10/2003 146 144 137 4 2.7% 12/03/2005 781 187* 21 2.7% 26/11/2005 1162 185* 19 1.6% 18/11/2006 1089 200* 4 0.4% 19/09/2007 337 240* 1 0.3% Totals 3515 144 49 1.4%

Table 19: Barramundi tagged and stocked in batches and recaptured in Clare Weir

1400 3.0% CLARE WEIR 1200 Stocked 2.5% % Recap 1000

2.0% S D E E R K U

C 800 T O P T

1.5% A S C

E

H 600 R S

I F

1.0% % 400

200 0.5%

0 0.0% 3 5 5 6 7 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 / / / / / 0 3 1 1 9 1 0 1 1 0 / / / / / 0 2 6 8 9 3 1 2 1 1

Figure 57: Recapture rates of batches of tagged Barramundi stocked in Clare Weir

From February 2005 to April 2007 there were 10 batch releases of stocked fish into natural lagoons on Barratta Creek and Sheepstation Creek. The locations were:

 Woodhouse Lagoon  Pegoraro Lagoon  Gorizia Lagoon  Gladys Lagoon  Church Lagoon  East Barratta Creek  Sheepstation Creek  West Barratta Creek  Dicks Lagoon

Batch releases and recaptures are shown in table 20. A total of 2,239 fish have been stocked for 24 (1.1%) recaptures. A total of 3,515 fish have been stocked for 49 (1.4%) recaptures. In table 20 for fish released (*) the lengths of individual fish were not recorded and the length was shown as the average length for all fish in the

page 66 batch. The highest recapture rate was in Gorizia Lagoon with 13 (8.8%) however 6 of those fish were recorded in a fish kill in January 2008.

From March 2004 to February 2007 there were 4 batch releases of stocked fish into Lake Proserpine as shown in table 21. A total of 567 fish have been stocked for 1 (0.2%) recapture. The average length of fish at release was 258mm.

Av Tag Length % Date Location Stocked Length of Recap Recaptured Recap 19/02/2005 Woodhouse 209 210* 0 0.0% 19/02/2005 Pegoraro 49 210* 3 6.1% 19/02/2005 Gorizia 147 210* 13 8.8% 19/02/2005 Gladys 50 210* 1 2.0% 11/03/2006 Church 802 205* 3 0.4% 18/03/2006 East Barratta 250 215* 4 1.6% 18/11/2006 Sheepstation 50 200* 0 0.0% 21/11/2006 West Barratta 531 200* 0 0.0% 6/03/2007 Dicks 100 160* 0 0.0% 28/04/2007 Dicks 50 325* 0 0.0% Totals 2238 24 1.1%

Table 20: Barramundi tagged and stocked in batches and recaptured in Barratta and Sheepstation Creek

Av Tag Length of Date Stocked Length Recaps Recaptured % Recap 21/03/2004 135 215 0 0.0% 26/05/2006 114 250 0 0.0% 26-27/10/2006 207 247 260 1 0.5% 10/02/2007 111 338 0 0.0% Totals 567 258 1 0.2%

Table 21: Barramundi tagged and stocked in batches in Lake Proserpine

Av Tag Length Date Location Stocked Length of Recaps Recaptured % Recap 28/01/2005 Lake Callide 600 198 196 12 2.0% 2/02/2005 Moura Weir 600 198 198 31 5.2% 5/02/2005 Alligator 1198 197 199 64 5.3% 8/02/2005 Bedford Weir 600 197 202 19 3.2% 10/02/2006 Moura Weir 600 207 208 61 10.2% 11/02/2006 Laurel Bank 3317 203 212 11 0.3% 1&24/2/2006 Bedford Weir 3541 212 213 15 0.4% 10/11/2007 Lake Theresa 850 2 0.2% Totals 11306 215 1.9%

Table 22: Barramundi tagged and stocked in batches in the Fitzroy Basin

page 67 From January 2005 to November 2007 there were 8 batch releases of stocked fish in the Fitzroy Basin as shown in table 22. These releases were in the river and impoundments and were released into:

 Lake Callide  Moura Weir  Alligator Creek  Bedford Weir  Fitzroy River at Laurel Bank

A total of 11,306 fish have been stocked for 215 (1.9%) recaptured. The highest recapture rate was for the 2006 release in Moura Weir with a recapture rate of 10.2%. All expect 1 of these fish were recorded in a fish kill that occurred in winter 2007.8 For recaptures the average length at tagging was not significantly different from the average size of fish released.

It should be noted that recaptures are still being made from these releases, except from the 2005 Lake Callide release were all fish were likely to have been lost in the winter 2007 fish kill. It is expected that the recapture rate will increase over the next few years.

From January 1996 to June 2000 there were 11 monthly releases of batches of tagged fish into Lake Awoonga as shown in table 23.

A total of 13,576 fish have been stocked for 202 (1.5%) recaptures. The highest recapture rate of 8.5% was for fish in the initial release in January 1996.

Av Tag Length Date Stocked Length of Recaps Recaptured % Recap 20/01/1996 201 302 301 17 8.5% 27/05/1997 232 128 0 0.0% 3-27/6/1997 1316 119 0 0.0% 5-27/2/1998 610 182 195 20 3.3% 12-31/3/1998 740 221 226 34 4.6% 7-30/4/1998 1043 234 256 27 2.6% 7-21/5/1998 674 244 280 6 0.9% 9-23/2/2000 2968 174* 87 2.9% 1-3/3/2000 773 174* 10 1.3% 31/05/2000 1269 155* 1 0.1% 1-7/6/2000 3750 155* 0 0.0% Totals 13576 202 1.5%

Table 23: Barramundi tagged and stocked in batches and recaptured in Lake Awoonga

The average length of fish released ranged from 119mm in June 1997 to 302mm in January 1996. For fish released (*) the length of individual fish were not recorded and the length was shown as the average length for all fish in the batch. For recaptures the average length at tagging was generally higher than the average size of fish released.

Figure 58 shows the recapture rate for the batches of fish released into Lake Awoonga. It should be noted that recaptures are still being made from these releases, however the number of future recaptures is expected to be low, particularly for the releases in earlier years. It is expected that the recapture rate may increase a little for the later releases over the next few years.

8 See Fish Death Events: Impact on stocked fish: Winter 2007

page 68 4000 9.0% LAKE AWOONGA 3500 8.0%

Stocked 7.0% 3000 % Recap

6.0% D D E

E 2500 R K U C 5.0% T O P

T 2000 A S 4.0% C E H R S

I 1500 F

3.0% % 1000 2.0%

500 1.0%

0 0.0% 6 7 7 8 8 8 8 0 0 0 0 9 9 9 9 9 9 9 0 0 0 0 9 9 9 9 9 9 9 0 0 0 0 - 1 1 1 1 1 1 1 2 2 2 2 2 / / / / / / / / / / / 1 1 5 6 2 3 4 5 2 3 5 6 / / / / / / / / 0 0 0 / / 7 7 1 0 1 3 3 / 7 - - 0 7 2 2 3 3 2 2 1 - - - - - 1 1 2 2 3 3 5 7 7 9

Figure 58: Recapture rates of batches of tagged Barramundi stocked in Lake Awoonga

Recapture rates for Barramundi in a number of rivers and waterways were calculated for comparison. These were:

 Weipa Rivers (Mission River, Embley River, Hey River, Pine River and Albatross Bay)  Johnstone River  Haughton River  Fitzroy River  12 Mile Creek (Marmor)  Mary River

12 Mile Creek is a small waterway which is isolated most of the time and is comparable to a small impoundment. It is mostly used by juvenile Barramundi of a similar size to those stocked in batches.

Table 24 shows the number of fish tagged and recaptured from 1985-2008. The overall recapture of Barramundi in these waterways is 9.8% however is as low as 2.0% for Weipa River and as high as 23.5% for 12 Mile Creek. In 1996 there were 1,519 fish tagged in 12 Mile Creek over about 2 months at an average length of 222mm. This was similar to a batch release of stocked fish and the recapture rate was 32.2%. Figure 59 shows the Barramundi tagged and the recapture rates in these waterways.

page 69 Waterway Tagged Av Length Recaps % Recap Weipa Rivers 27109 465 535 2.0% Johnstone River 5162 343 584 11.3% Haughton River 1435 474 163 11.4% Fitzroy River 13518 464 2454 18.2% 12 Mile Creek 5788 317 1359 23.5% 12 Mile Creek 1996 1519 222 489 32.2% Mary River 2369 473 327 13.8% Total 56900 5911 10.4%

Table 24: Barramundi tagged and recaptured in a number of Queensland waterways

30000 35.0% QLD RIVERS 30.0% 25000 Tagged % Recap 25.0%

20000 D D E E R G

20.0% U G T P A 15000 T A

C H

15.0% E S R I

F

10000 % 10.0%

5000 5.0%

0 0.0% r r n s e k k e e r o e e n r v t v e r i i e e o e v e h r r t R i R 6 v

s v g i C C i R 9 y y n u R R r e e 9 o a l l h a i i a r 1 p o H z i J M M M t

e i F 2 2 W 1 1

Figure 59: Barramundi tagged and recapture rates in a number of Queensland waterways

6.2 Batch Release of Murray Cod

There has been 1 batch release of Murray Cod in Lake Coolmunda at Inglewood.A total of 196 fish were tagged and batch released in the lake in September 2006 as shown in table 25. The average length of the fish on release was 317mm and no fish have been recaptured.

Tag Length Date Stocked Av Length of Recap Recaptured % Recap 16/09/2006 196 317 0 0.0%

Table 25: Murray Cod tagged and stocked in batches and recaptured in Lake Coolmunda

page 70 6.3 Discussion on Survival of fish in Batch Releases

Care needs to be taken in any interpretation of fish survival from recapture rates as these are influenced by many factors and should only be considered as indicative. The recapture rate was influenced by:

 The amount of fishing effort (most important factor)  Time elapsed after tagging  Tag shedding or loss of tag  Tags overgrowing and becoming internal in the fish flesh  Non reporting of recaptures  Fish moving to other areas  Natural mortality

The effect of fishing effort can be demonstrated by a recapture rate of 2.0% for the Weipa Rivers where overall fishing effort is low and the area large compared with 23.5% for 12 Mile Creek where the area is small with a high level of fishing effort. At 12 Mile Creek the average number of fishers was 731 per year (2 fishers/day) from 1997/98 to 2000/01.9

A study of Barramundi survival in the Northern Territory showed a survival rate of 80%10 so it is expected that the survival rate of batches of tagged stocked fish should be at around that level.

The highest recapture rate for batches of tagged stocked fish was 16.5% for a batch release in Black Weir in 2000. This area is heavily fished and there has been sufficient time since the release for most recaptures to be made.

While the recapture rates of other batches are generally below 10% for most releases these have mostly been made since 2002 and fish from these releases are still being recaptured. It is expected that the rates will increase for most releases over the next few years.

However some observations can be made that may be useful to stocking groups. In Lake Tinaroo there were 9 releases of batches of fish. Recapture rates of fish released in spring and summer range from 1.0-4.1% while for releases in late autumn and winter the recapture rate is 0.0% with only 1 of 1,187 being recaptured. This may indicate a lower survival rate for winter releases.

Releases of batches of fish into Lake Awoonga during summer and early autumn (to April) had recapture rates ranging from 1.3-8.5% while releases in late autumn (May) and winter had recapture rates ranging from 0.0-0.9%. For winter releases of 5,066 fish in 1997 and 2000 there have been no recaptures. However fish released in winter into Lake Awoonga were smaller than most other batch releases with the average length of fish ranging from 119-155mm. This winter result is similar to that in Lake Tinaroo. However it may also have been influenced by the smaller size of fish released. It is generally recommended that fish below 150mm not be tagged using conventional tags.

A winter release in Mulgrave River in 2004 had a recapture rate of 2.2% while for a winter release in 2008 there have been no recaptures, however this was a recent release and recaptures could occur in the future. It may be possible that winter releases in rivers may have a better survival rate than such releases in impoundments.

Batch releases of fish at discrete sites in Trinity Inlet and the Barron River indicate that there may be some sites with higher survival rates than other sites. There were common sites in 2 releases in 2002 and 2004 and for both releases Hills Creek recorded recapture rates of 4.2% and 3.3% while for Redbank Creek the rates were 0.7% and 1.5%. Recapture rates for both releases were higher at Hills Creek.

9 Revegetation of 12 Mile Creek at Marmor 2001 report 10 Assessment of Post Release Survival and Stress Physiology of Barramundi – Paul de Lestang et al 2004

page 71 However care needs to be taken in any interpretation of this due to the low numbers of recaptures from each site.

Where length data were available for individual fish a comparison was made between the average length of fish released in the batch with the length at tagging of recaptured fish. This was used to determine if there any difference in the length of fish released and those recaptured. For most batch releases there was no significant difference. For Lake Awoonga the recaptured fish from most releases were slightly longer that average length of the fish released. This indicates a higher recapture rate for larger fish released and perhaps a slightly higher survival rate.

However based on the overall recapture rates there is little difference in the recapture rates based on length of fish at release indicating that there may be little difference for fish over about 150mm.

Recapture rates in a number of rivers indicate that the rate are generally significantly higher than for batches of stocked fish however these differences may to be related to the factors affecting the recapture rate rather than any differences in overall survival.

page 72 7. Survival of Fish in Impoundments where Low Water Levels were experienced

7.1 Low Water Levels and Australian Bass and Golden Perch

There were 3 impoundments where water levels were very low during the period of the report where stocked fish have been tagged. Fish stocked in these impoundments that were tagged were Australian Bass and Golden Perch. These impoundments were:

 Lake Boondooma  Lake Barambah  Lake Moogerah

1990/91 1991/92 1992/93 1993/94 1994/95 BOONDOOMA TAGGED 10 164 849 649 550 BOONDOOMA RECAPS 0 4 16 53 74 BARAMBAH TAGGED 5 BARAMBAH RECAPS 1 MOOGERAH TAGGED 2 85 346 291 1061 MOOGERAH RECAPS 0 1 5 17 35 1995/96 1996/97 1997/98 1998/99 1999/00 BOONDOOMA TAGGED 68 1524 619 684 1723 BOONDOOMA RECAPS 35 100 106 67 95 BARAMBAH TAGGED 13 14 BARAMBAH RECAPS 0 0 MOOGERAH TAGGED 453 962 710 576 315 MOOGERAH RECAPS 55 53 97 127 57 2000/01 2001/02 2002/03 2003/04 2004/05 BOONDOOMA TAGGED 1319 773 867 1280 827 BOONDOOMA RECAPS 106 97 154 156 106 BARAMBAH TAGGED 15 0 0 695 595 BARAMBAH RECAPS 0 0 0 18 35 MOOGERAH TAGGED 336 424 358 26 55 MOOGERAH RECAPS 64 106 98 7 1 2005/06 2006/07 2007/08 2008/09* BOONDOOMA TAGGED 450 433 295 36 BOONDOOMA RECAPS 81 87 31 16 BARAMBAH TAGGED 819 45 5 8 BARAMBAH RECAPS 50 30 5 0 MOOGERAH TAGGED 2 106 145 1 MOOGERAH RECAPS 5 7 6 0

Table 26: Summary of fish tagged and recaptured each year in Lakes Boondooma, Barambah and Moogerah (*2008/09 to 31/12/2008)

Water level data for Lake Boondooma and Barambah were obtained from Sunwater. Daily water level data for both lakes were available from 1/8/2001 to 31/12/200811 and water levels at the end of each month were assessed with fish tagged and recaptured that month.

For Lake Boondooma the water level reached a low of 10% in November-December 2007 while Lake Barambah reached a record low of 2% from June-December 2007.

11 Water level data for Lake Boondooma and Barambah were supplied by Sunwater Bundaberg

page 73 Table 26 shows the number of fish tagged and recaptured in each of the 3 impoundments for each year from 1990/91 to 2008/08. Figures 60 and 61 show the fish tagged and recaptured compared with water levels from 2001/02 to 2007/08 for Lake Boondooma and Barambah.

400 90

LAKE BOONDOOMA 350 80 Tagged Recaps 70 300 % Full 60 250 M A

50 D

H L S

200 L I F U

40 F

150 % 30

100 20

50 10

0 0

Figure 60: Fish tagged and released each month and water levels in Lake Boondooma from

400 100

LAKE BARAMBAH 90 350 Tagged 80 300 Recap % Full 70

250 L

60 L U F H S M

I 200 50 A F D

40 150 % 30 100 20 50 10

0 0

2001/02 to 2008/09 Figure 61: Fish tagged and released each month and water levels in Lake Barambah from 2001/02 to 2008/09

For Lake Boondooma the minimum water level was 10% in November-December 2007 however fish were continued to be tagged and recaptured during and after the lowest water levels, although at a lower rate than in previous years. Since October 2007 when water levels reached their lowest there have been 32 recaptures with 30 of these fish having been tagged before October 2007 and as far back as 1999.

For Lake Barambah the minimum water level was 2% from June-December 2007 which was significantly lower and over a longer period than in Lake Boondooma. Water levels dropped to below 5% in April 2007 and stayed below that level until March 2008. This is reflected in the low number of fish tagged in 2007/08 with only 5 fish tagged. Since April 2007 there have been 5 fish recaptured with no recaptures occurring after September 2007 and no recaptures since the dam level rose again.

page 74 Water level data for Lake Moogerah were obtained from . Daily water levels were available from 1/7/2001 to 30/6/2008 and were converted to a percentage of full dam capacity using a storage curve supplied by Seqwater12. Water level data prior to 1/7/2001 was not available however it was reported that during the 1995 drought dam levels declined to a low of 1% total capacity13.

1200 LAKE MOOGERAH FISH TAGGED AND RECAPTURED

1000 TAGGED Dam RECAPTURED reached

H 800 low of S I 1% F

F O 600 R E B M U

N 400

200

0 0 1 2 3 4 5 6 7 8 9 0 1 9 9 9 9 9 9 9 9 9 9 0 0 / / / / / / / / / / / / 9 0 1 2 3 4 5 6 7 8 9 0 8 9 9 9 9 9 9 9 9 9 9 0 9 9 9 9 9 9 9 9 9 9 9 0 1 1 1 1 1 1 1 1 1 1 1 2

Figure 62: Fish tagged and recaptured in Lake Moogerah from 1989/90 to 2000/2001 From 1989/90 to 2000/01 there were 5,142 fish tagged, almost all being Australian Bass. Of these there have been 530 fish recaptured (10.3%). This compared with an overall recapture rate of 8.5% for Australian Bass and 9.2% for Golden Perch tagged in impoundments14.

Figure 62 shows the number of fish tagged and recaptured from 1989/90 to 2000/01. While water levels for this period are not available the dam was reported to have reached a low level of 1% of capacity in 1995.

A total of 1,787 fish were tagged from 1989/90 to 1994/95 before the dam reached a low of 1%. Of these fish 56 (3.1%) were recaptured up to the end of 1994/95. A further 227 (12.7%) were captured from 1995/96 to 2003/04 with the last fish reported as being recaptured in September 2003.

There were 453 fish tagged during the low water levels of 1995/96 with 1 (0.2%) fish recaptured during that year. A further 37 (8.2%) fish were recaptured after 1995/96 up to 2002/03 with the last fish being reported as recaptured in November 2002.

From 1996/97 to 2000/01 there were 2,902 fish tagged with 231 (8.0%) being recaptured during that same period. A further 141 (4.9%) were recaptured after 2000/01 up to 2007/08 with the last fish being reported as recaptured in September 2007. During that period water levels dropped to around 2.6% and were below 5% for 2 lengthy periods (figure 63).

Figure 63 shows the numbers of fish tagged and recaptured each month from 2001/02 to 2007/08 compared with dam levels. Over that time there were a total of 1,192 fish tagged and 44 (3.7%) of these recaptured.

12 Water levels based on Australian Height Datum for Lake Moogerah and storage curve supplied by Seqwater Brisbane 13 From http://en.wikipedia.org/wiki/Lake_Moogerah and Collie, Gordon, Worst Drought of Century cripples farmers: Courier Mail 26 August 1995 14 See Summary of tagging of stocked fish in impoundments and waterways of Queensland 1987-2007

page 75 Tagging effort continued during the periods of low water levels during 2002/03 and 2006/07.

250 100% MOOGERAH FISH AND DAM CAPACITY 90%

200 80% TAGGED RECAPTURED 70%

H % CAPACITY S I

F 150 60%

L F L O U

50% F R

E % B

M 100 40% U N 30%

50 20%

10%

0 0%

Figure 63: Fish tagged and recaptured each month in Lake Moogerah compared with dam levels from 2001/02 to 2007/08

7.2 Discussions on Low Water Levels

The data available on the effects of low water levels is limited so that any assessment of survival of fish during these periods needs to be treated with caution.

Water levels in Lake Boondooma reached a minimum level of 10% however fish have been tagged during and since these low levels were reached even if at a reduced level. There a number of factors that need to be taken into account. These are:

 There has been a reduction in tagging effort as a number of keen taggers in the past have ceased tagging.  Low water levels make access to the water and movement around the impoundment more difficult so this could influence fishing effort.  It may be possible that there was a level of mortality of fish during the low water levels however no fish deaths were reported, even during winter 2007 when there were widespread fish deaths reported in impoundments15.

Recaptures have also continued, with many fish recaptured having been tagged prior to the low water levels being reached. While numbers of recaptures have reduced this could be related to lower fishing effort and fewer fish being tagged in recent years.

The evidence suggests that minimum water levels of around 10% are not likely to have a significant impact of the survival of stocked fish in Lake Boondooma. However this is based on data from 1 impoundment only and may not reflect what may happen in other impoundments.

Water levels in Lake Barambah reached a low of 2% and stayed below 5% for around 23 months from April 2006 to February 2008. A small number of fish were tagged and recaptured during the early part of this period however few fish have been tagged since then or after the water level rose again. There were no recaptures after 18 months into that low water period and none since water levels rose again.

15 See Fish death events: Impact on stocked fish: Winter 2007

page 76 The evidence suggests that these low water levels may have had an impact on stocked fish although no assessment of the level of this impact is possible.

Water levels in Lake Moogerah were reported as reaching a low of 1% in 1995 however for fish tagged prior to that low level the recapture rate after that event was 12.7% which is higher than the overall recapture rate for stocked fish. This suggests a high level of survival following a very low water level.

Recapture rates of fish tagged prior to low water level periods in 2002/03 and 2006/07 and recaptured after those times were 4.9% and 3.7%. These rates were lower than after the low levels in 1995 however similar factors to those that applied at Lake Boondooma are likely to have applied to Lake Moogerah after 2002/03.

Based on the limited available data it is likely that, at least for Australian Bass, water levels of 10% of full capacity are unlikely to the have any significant effect on survival. For water levels below 5%, while there is some evidence of lower survival, it would appear that fish can survive very low water levels even down to 1%. It is likely that there is some additional mortality at these low levels however it is not possible to assess the level of the impact.

page 77 8. Implications for Future Stocking

This report provides Queensland Primary Industries and Fisheries and stocking groups with information that can be used to assist with future stocking strategies.

Growth of Barramundi stocked in impoundments is particularly variable in individual impoundments and may also vary over time within an impoundment. Growth is likely to be dependent on climatic conditions, size and depth of impoundment, available food and genetic characteristics of the broodstock used. The data supports a higher growth rate for stocked fish in freshwater compared with wild fish in saltwater estuaries. This is also reflected in wild fish that access freshwater where their growth rate is also higher.

Growth of Australian Bass in also higher in impoundments compared with those in a natural river system like the Noosa River. However for Golden Perch the growth rate of fish in impoundments was not significantly different from fish in the Dawson River except for those in Lake Leslie where the growth rate was significantly higher.

The data on growth in impoundments will allow stocking groups to assess growth for fish they are stocking and how that might influence future stockings.

There have now been a significant number of batch releases of Barramundi both in impoundments and waterways. For stocking in open waterways the data indicates that “leakage” of fish outside that system is low so that any genetic impacts on wild fish are likely to be localised in that system. However appropriate practices in relation to using broodstock, with as wide a gene pool as possible, in hatcheries will ensure there is little likelihood of adverse impacts on the genetics of wild stock.

For batch releases of Barramundi there was little evidence of differences in the recapture rates for tagged fish stocked at lengths over 150mm. This would suggest that if larger fish are intended to be stocked then using fish around 150-200mm would be more economical than larger fish without any likelihood of a significant difference in survival.

Few stocked fish of any species moved outside impoundments. Where there is a high dam wall the number of fish going over the wall or spillway and surviving is low and there are only low numbers of fish that move upstream of the impoundment. However the data relates to a period where there have been prolonged dry periods and droughts and more fish would be expected to move outside impoundments during very wet years.

For impoundments where Australian Bass and Golden Perch are stocked recapture rates suggest that low water levels of around 10% are unlikely to result in significant mortality. When levels fall below 5% it is likely that there is an increase in mortality however in some impoundments fish can have high survival rates even when levels reach 1%.

Managing low water levels to keep them above 5% is difficult and if climate change predictions are accurate then the climate is likely to be dryer and the incidence of impoundment water levels dropping below that level are likely to increase. Stocking groups need to assess how often these levels have been reached and the likelihood of this occurring in the future. A risk approach needs to be taken when determining future stocking strategies.

page 78 page 79