Winter 2007 Fish Kills Impact on Stocked Fish

Error! No text of specified style in document. Winter 2007 Fish Death Events: Impact on stocked fish

Report prepared for the Department of Primary Industries by Infofish Services

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

Published August 2008

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-2008-20

 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 2 Table of Contents

Acknowledgements...... 4 1. Summary...... 5 1. Introduction...... 7 2. Aims...... 7 3. Fish Death Events in Stocked Impoundments in Geographic Divisions...... 8 3. Weather Conditions in Winter 2007 ...... 10 2. Temperature Tolerance of Stocked Species ...... 14 3. Impact of Fish Death Events on the Stocking Program...... 15 4. Implications for Future Stocking...... 16 5. Gulf of Carpentaria Division...... 18 6. North Queensland Division...... 26 7. Central Queensland Division...... 33 8. Mary/Burnett Division...... 48 9. South East Queensland Division...... 59 List of Figures Figure 1: Geographic divisions based on catchments where stocking has occurred 8 Figure 2: Locations where fish deaths occurred in winter 2007 9 Figure 3: Minimum air temperatures at Mount Isa in July and August 2007 10 Figure 4: Minimum air temperatures at Atherton in July and August 2007 11 Figure 5: Minimum air temperatures at Emerald in July and August 2007 11 Figure 6: Minimum air temperatures at Maryborough in July and August 2007 12 Figure 7: Minimum air temperatures at Amberley in July and August 2007 13 Figure 8: Comparison of long term average minimum temperatures with monthly minimums for July and August 2007 13 Figure 9: Part of the Barramundi that died in Lake Moondarra (Photograph courtesy of Mount Isa Fish Stocking Association) 21 Figure 10: Barramundi sizes in Moura Weir fish death event showing fish from different stockings 38 Figure 11: Dead fish (mostly Bony Bream) and floating scum in Moura Weir (photograph courtesy of SunWater Biloela) 38 Figure 12: Fish death event in Lake Callide (Photographs courtesy of John Barber SunWater Biloela) 45 Figure 13: Dead Barramundi at Lake Lenthall (Paul Dolan photographs) 53 Figure 14: Dead Barramundi in the Burnett River downstream from Gayndah (Photograph courtesy of EPA Marybough) 55 Figure 15: Close up of dead Barramundi in Burnett River (photograph courtesy of EPA Maryborough) 56 List of Tables Table 1: Estimate of total fish deaths in each geographic division ...... 16 Table 2: Summary of dead fish in impoundments in Gulf of Carpentaria Division ...... 18 Table 3: Summary of dead fish in impoundments in the North Queensland Division ...... 26 Table 4: Summary of dead fish in impoundments in Central Queensland division ...... 33 Table 5: Summary of dead fish in impoundments and waterways in the Mary/Burnett Division . 48 Table 6: Summary of fish deaths in impoundments and waterways of South East Queensland.. 59

page 3 Acknowledgements

The compilation of this report required obtaining information from a wide range of sources. It is not possible to identify all the individuals that contributed to information in this report however the organisations and key individuals in some of those organisations need to be acknowledged.

The Department of Primary Industries and Fisheries (DPI&F), in particular Terry Healy and Peter Kind were instrumental in recognising the importance of documenting the impacts of the fish death event in winter 2007 as this would provide useful information to the Department and to stocking groups that could be used in future management and stocking decisions.

The contribution of other DPI&F officers that provided information on the fish death events and the stocking of impoundments is also acknowledged. This included Stephanie Chellan, Shaun Pobar and Chris Lupton.

The Environmental Protection Agency is also acknowledged, particularly the Mount Isa regional office and the Maryborough regional office, and other offices that investigated the reports of fish death events and provided reports of their findings.

SunWater is also acknowledged, particularly the Biloela regional office, and other offices that also investigated fish death events in impoundments which they manage and provided reports on their findings.

Gladstone Area Water Board Hatchery is also acknowledged. Kurt Hutchby provided information on the fish deaths in Lake Awoonga and additional information on deaths in a number of other impoundments.

Members of local stocking groups also provided important information on the fish death events including Mount Isa Fish Stocking Group, Fitzroy River Fish Stocking Association, Callide Fish Stocking Group, Clermont Fish Stocking Group, Fraser Coast Fish Stocking Group and Gary Sturdy of Lake Kurwongbah Fish Stocking Group.

page 4 1. Summary

Winter 2007, particularly July, was much colder than the long term average across much of the State, particularly away from the coast.

Around the middle of the month the first reports started to emerge of fish death events, particularly from impoundments that had been stocked with fish over the past 20 years. The initial reports came from Lake Moondarra in the Mount Isa area but by the end of the month reports were received from many locations in central and southern parts of the State.

It rapidly emerged that Barramundi were the most affected species in central and northern impoundments while Tilapia were the most affected species in southern impoundments. The widespread occurrence of fish death events from Lake Moondarra in the north to Lake Somerset in the south, with tropical species the most affected, and all deaths occurring roughly at the same time it was considered that low water temperatures were likely to be the primary cause of the fish death events.

During July there was a period of almost 3 weeks where minimum air temperatures were mostly lower than the long term average by around 1oC in the north of the State to 2-2.5oC in the south. This is not a common occurrence as the last time this occurred was during the 1950s in the central and northern parts of the State. This resulted in significant drops in water temperatures to around 14oC in Lake Moondarra at Mount Isa and 10oC in Lake Callide at Biloela which was the lowest temperature recorded.

Barramundi have been stocked in many impoundments in the north down to those in the Mary/Burnett in the south. Barramundi appear to become less active and reduce feeding when temperatures are below about 18oC but it is likely they can withstand temperatures as low as 14oC for short periods. However, if temperatures stay that low for extended periods (days or weeks), fish may die.

Water temperatures as low as 14oC were recorded in many of the impoundments and this corresponded with fish deaths, involving primarily Barramundi, in many of these impoundments. This was also compounded by low water levels in many of the impoundments which would have contributed to low water temperatures. In many of these impoundments not all fish died however in Lake Callide, where the temperature fell to 10oC, all Barramundi appear to have died as no fish have been caught since that time.

While a number of other species were involved in the deaths it was Barramundi that was affected the most. In all it is estimated that over 40,000 fish died. It is estimated that around 32,720 Barramundi died and based on the estimated average size of fish in each division that died it is estimated that this is equivalent to around 220 tonnes of fish.

In Lake Callide from a batch of 600 tagged Barramundi at ~200mm stocked in 2005 only one was recovered from the dead fish. This was in an impoundment where there were ~12,000 large Barramundi and water levels at 8%. This suggests that the larger fish are likely to have eaten the smaller fish.

page 5 Divisison Fish Barramundi Others deaths deaths Gulf of Carpentaria ~3,500 ~2,500 Forktail Catfish, Sleepy (20t) Cod, Sooty Grunter, Bony Bream, Eeltail Catfish, Longtom North Queensland <100 <100 (0.5t) Sooty Grunter Central ~29,420 ~25,120 Bony Bream, Catfish Queensland (176t) Mary/Burnett ~5,300 ~5,000 (25t) Australian Bass, Gudgeon, Eel, Bony Bream, Forktail Catfish and Eeltail Catfish South East Large Not stocked in Tilapia, Bony Bream, Queensland numbers SEQ Forktail Catfish, Eel, but no impoundments Turtle estimate Estimated total >40,000 ~32,720 (221.5t)

By contrast in Moura Weir where a similar batch of 600 tagged were released at the same time and a further batch of 600 released in 2006 of the ~200 fish that died 78 (~40%) were tagged fish indicating a high level of survival. The Barramundi population in Moura Weir is not dominated to the same extent by large fish with many leaving the weir to migrate downstream to the Fitzroy River when flow opportunities allow.

Based on this, and work in Lake Tinaroo, it suggests that stocking Barramundi, or any other fingerlings, into impoundments where there is already a significant number of large Barramundi is not likely to increase the size of the fishery as most fish are likely to be eaten by the larger Barramundi. This is probably not an effective use of stocking funds. Stocking groups will need to consider what sort of fishery they prefer and develop a stocking regime that will meet their expectations.

In impoundments in South East Queensland another tropical species Tilapia had the most deaths. Tilapia is an introduced species that is considered a noxious pest so that the deaths in this area may be considered as being beneficial in reducing numbers of this pest rather than being detrimental.

While the fish deaths were devastating for some Stocking Groups there were some useful lessons to be learnt with implications for future stocking strategies.

Long term weather records indicate that the last time a similar event occurred was in the 1950s so it can be expected that such events are not likely to occur regularly. Such events may even become less frequent in the future if climate change predictions are correct.

However some impoundments, especially those that are susceptible to lower than average temperatures over winter and/or have persistently low water levels may need to develop a risk management strategy to reduce the impact of future fish death events. This may be by stocking more temperature tolerant species or continuing to stock the same species but more conservatively and taking the risk that such events are likely to be rare.

page 6 Winter 2007 Fish Death Events Impact on Stocked Fish

1. Introduction

Winter 2007, particularly July, was much colder than the long term average across much of the State, particularly away from the coast.

Around the middle of the month the first reports started to emerge of fish death events, particularly from impoundments that have been stocked with fish over the past 20 years. The initial reports came from Lake Moondarra in the Mount Isa area but by the end of the month reports were received from many locations in central and southern parts of the State.

It rapidly emerged that Barramundi were the most affected species in central and northern impoundments while Tilapia were the most affected species in southern impoundments. The widespread occurrence of fish death events from Lake Moondarra in the north to Lake Somerset in the south, with tropical species were the most effected, and all deaths occurring roughly at the same time it was considered that low water temperatures were likely to be the primary cause for the fish death events.

Reports were received and collated from many sources by the Department of Primary Industries and Fisheries, Environmental Protection Agency, SunWater, other managers of impoundments, Stocking Groups and Infofish Services as well as reported widely through the media.

As most of the fish death events were in impoundments that have been stocked by local fish stocking groups it was considered that an assessment be made of the impact of the fish death events on the stocking program.

2. Aims

The aims of this report are to:

 Review the weather conditions that existed in winter 2007 and the effect of this on stocked impoundments  Document the locations and extent of the fish death events that occurred in stocked impoundments and elsewhere during winter 2007  Assess the impact of the fish death events on the fish stocking program  Identify information from the fish death events that will be of benefit to fish stocking groups in the future

page 7 3. Fish Death Events in Stocked Impoundments 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 at www.ffsaq.ausfish.com.au/ (figure 1).

Reporting on the fish death events is based around impoundments and waterways in each of the geographic divisions. A summary is provided for each impoundment or waterway including:

 Location and map  Weather in July-August 2007  Stocking history  Date reported  Reported by  Reported to  Investigated by  Report available  Species involved  Fish recaptured  Numbers of dead fish  Tagged fish recovered  Size range  Water level  Water temperature  Water samples taken  Results of water samples  Presumptive prognosis  Comments

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

page 8 Locations of fish deaths reported in stocked impoundments and waterways during winter 2007 are shown in figure 2.

LAKE TINAROO

LAKE MARY CHINAMAN CREEK KATHLEEN RESERVOIR LAKE EUNGELLA LAKE LAKE TEEMBURRA MOONDARRA

LAKE THERESA

LAKE MARABOON BARALABAWEIR LAKE AWOONGA MOURAWEIR LAKE CALLIDE LAKE MONDURAN GAYNDAH LAKE LENTHALL

CABOOLTURE RIVER LAKE KURWONGBAH LAKE SOMERSET LAKE SAMSONVALE LAKE WIVENHOE LAKE MOOGERAH

Figure 2: Locations where fish deaths occurred in winter 2007

page 9 3. Weather Conditions in Winter 2007

A number of sites in the geographic divisions that were in the vicinity of the fish death events were selected to compare long term average winter temperatures for July and August. Daily temperature data were obtained for these months obtained from the Bureau of Meteorology website http://www.bom.gov.au. These sites were also considered to provide indicative minimum temperatures for impoundments in the relevant geographic division.

Mount Isa in the Gulf of Carpentaria Division

Site name: Mount Isa Aero Site number: 029127 Latitude: 20.68oS Longitude: 139.49oE Elevation: 340m Long term July average minimum temperature: 8.6oC July 2007 average minimum temperate: 7.6oC Days below minimum average temperatures in July: 23 (76.7%) Long term August average minimum temperature: 10.3oC August 2007 average minimum temperate: 10.5oC Days below minimum average temperatures in August: 11 (35.4%)

18 MOUNT ISA MINIMUM TEMPERATURES 16 MIN TEMP E 14 R MIN AVG U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

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

Figure 3: Minimum air temperatures at Mount Isa in July and August 2007 Atherton in the North Queensland Division

Site name: Atherton Post Office Site number: 031002 Latitude: 17.27oS Longitude: 148.45oE Elevation: 752m Long term July average minimum temperature: 10.4oC July 2007 average minimum temperate: 7.5oC Days below minimum average temperatures in July: 14 of 21 (66.7%) Long term August average minimum temperature: 9.9oC August 2007 average minimum temperate: 13.2oC Days below minimum average temperatures in August: 3 of 24 (12.5%)

page 10 20 ATHERTON MINIMUM TEMPERATURES

MIN TEMP 15 MIN AVG S E R U T

A 10 R E P M E T

M 5 U M I N I M

0 7 7 7 7 7 7 7 7 7 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8 0 0 0 0 0 0 0 0 0

-5 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

Figure 4: Minimum air temperatures at Atherton in July and August 2007 Emerald in the Central Queensland Division

Site name: Emerald Airport Site number: 035264 Latitude: 23.57oS Longitude: 148.18oE Elevation: 189m Long term July average minimum temperature: 8.9oC July 2007 average minimum temperate: 7.0oC Days below minimum average temperatures in July: 24 (77.4%) Long term August average minimum temperature: 10.2oC August 2007 average minimum temperate: 11.2oC Days below minimum average temperatures in August: 10 (32.2%)

18 EMERALD MINIMUM TEMPERATURES 16

14 MIN TEMP E

R MIN AVG U

T 12 A R E

P 10 M E T 8 M U M

I 6 N I

M 4

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

Figure 5: Minimum air temperatures at Emerald in July and August 2007

page 11 Maryborough in the Mary/Burnett Division Site name: Maryborough Site number: 040126 Latitude: 25.52oS Longitude: 152.72oE Elevation: 10m Long term July average minimum temperature: 8.6oC July 2007 average minimum temperate: 5.4oC Days below minimum average temperatures in July: 24 (77.4%) Long term August average minimum temperature: 9.3oC August 2007 average minimum temperate: 11.0oC Days below minimum average temperatures in August: 10 (32.2%)

20 MARYBOROUGH MINIMUM TEMPERATURES 18

16 MIN TEMP MIN AVG

E 14 R U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

0 7 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 0

-2 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 / / / / / / / / / 7 7 7 7 7 8 8 8 8 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

Figure 6: Minimum air temperatures at Maryborough in July and August 2007

Amberley in the South East Queensland Division

Site name: Amberley AMO Site number: 040004 Latitude: 27.63oS Longitude: 152.71oE Elevation: 24m Long term July average minimum temperature: 5.3oC July 2007 average minimum temperate: 2.4oC Days below minimum average temperatures in July: 24 (77.4%) Long term August average minimum temperature: 6.3oC August 2007 average minimum temperate: 8.2oC Days below minimum average temperatures in August: 10 (33.3%)

page 12 20

AMBERLEY MINIMUM TEMPERATURES

15 MIN TEMP MIN AVG E R

U 10 T A R E P M

E 5 T

M U M I

N 0 I 7 7 7 7 7 7 7 7 7 M 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-5 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

-10

Figure 7: Minimum air temperatures at Amberley in July and August 2007

Figure 8 provides a comparison of long term average and monthly average temperatures in July and August 2007 for centres in each geographic division. This indicates that 2007 minimum temperatures were lower than the long term average by around 1.0oC in the north to around 2-2.5oC in the south during July. On 66-77% of days in July temperatures were lower than the long term average. In August the monthly minimum temperatures were above the long term average by 0.2-1.9oC and only below average on 12- 33% of days and this was mostly at the start of the month.

16 MINIMUM MONTHLY TEMPERATURES 14

E LONG TERM AVERAGE R

U 12 2007 T A

R 10 E P M

E 8 T

M 6 U M I

N 4 I M 2

0 Y Y A D A D N N H H E E L L S S O O G G I L I L A A

T T U U R R R R T T R R O E O E E E N E N E R B R B M M U H U H O O M M T E T E O O B B A A A A M Y M Y R R A A M M JULY AUGUST

Figure 8: Comparison of long term average minimum temperatures with monthly minimums for July and August 2007

page 13 This suggests that over most of Queensland the weather was colder than average in July and in the first half of August. This coincided with the start of the fish death events which commenced in early to mid July and continued through to mid August. It is likely that water temperatures dropped below temperatures in previous years and may have stayed lower for longer.

Such events with so many days in July being below the monthly minimum are not common with the last time such a long cold snap was recorded in Central and North Queensland was during the 1950s.1

2. Temperature Tolerance of Stocked Species

All fish species have a preferred water temperature range and if temperatures go outside that range that places significant stress on fish. If temperatures stay outside that range for an extended period, sometimes for a matter of days, this can be lethal for many species if they cannot find areas where the temperature is inside their range. It should also be remembered that water is much more difficult to heat or cool than air so water temperature in the dams may be significantly higher than air temperature in winter.

Barramundi have a broad range of temperature tolerance usually quoted as 15–35oC. However this may possibly vary with the genetic strain of the species. Southern strain barramundi (as stocked in Lake Awoonga, Lake Callide and Lake Monduran) may be more tolerant of lower temperatures. Barramundi appear to become less active and reduce feeding below about 18oC, but it is likely that they can withstand temperatures as low as 14oC for short periods. However, if temperatures stay this low for extended periods (days or weeks), fish may die.

Anecdotal observations suggest that Barramundi move to locations with higher temperatures within the dams in mid-winter, usually in shallower locations often with weed beds, where the water is likely to be heated during the middle of the day. However these are also likely to be the locations where temperatures may fall rapidly at night exposing fish to potentially lethal temperatures. In autumn or early winter the warmest water may be the deeper locations and fish may move to these.

The susceptibility of most animals to cold usually depends on their size. Large animals lose heat more slowly than small ones. This means that small Barramundi would be expected to die first, however large fish are also the slowest to heat up once their bodies have cooled, so that short warm periods in the middle of the day may be of most benefit to small fish. This may explain why most fish deaths recorded were large fish.

Bass are reportedly even more tolerant (3-30oC) but once again this may be dependent on genetic strain. However because of their smaller size they may be more impacted by rapid temperature falls.

There is only one species of Tilapia that is present in south eastern Queensland waters which is Mozambique Tilapia Oreochromis mossambicus. Scientific literature indicates 8-10oC as the minimum lethal thermal limit for this species and recent tolerance trials by the Australian Centre for Tropical

1 Mike Griffin pers comm. (retired Bureau of Meteorology)

page 14 Freshwater Research at James Cook University has found the minimum lethal limit to be 9-10oC.2

3. Impact of Fish Death Events on the Stocking Program

Some useful information from the fish deaths was obtained from impoundments where there were some tagged fish recovered. In 2 Central Queensland impoundments there were batches of larger tagged Barramundi stocked in 2005 and 2006. In Lake Callide there were 600 tagged Barramundi at ~200mm released in 2005. At the same time 600 tagged Barramundi, also at ~200mm, were released in Moura Weir with a further similar number released in 2006.

This provided a unique opportunity to compare the fate of these fish, especially those that were concurrently released in 2005. In Lake Callide only 1 tagged fish was recovered from that batch of released fish. As all fish died in Lake Callide this represents a low survival rate. In Moura Weir about 200 Barramundi died. Of these 78 (~40%) were tagged which is a significantly different result from that in Lake Callide. Also since then further tagged fish from Moura Wier have been recaptured. This suggests a high survival rate for the fish stocked in Moura Weir.

Around 12,000 Barramundi died in Lake Callide with most fish in the size range 700-1,200mm. From 2005, when the tagged fish were released, to 2007 the lake level was very low and only at 8% when the fish died. The combination of significant numbers of large Barramundi and low water levels would have resulted in low food supplies for the larger fish and it is likely that the tagged fish were cannabilised by the large fish.

In Moura Weir the overall population of Barramundi was not as high, especially for larger fish. Moura Weir is on the Dawson River and larger fish will leave the weir when there is a reasonable flow. Fish tagged in Moura Weir have been recaptured in the Fitzroy River estuary some 420km down river. Therefore the population in Moura Weir is not necessarily dominated by large fish. As most of the dead fish from Moura Weir were measured it showed that fish from 550-650mm were the dominant size class (from the 2006 stocking). This suggests that the population structure in Moura Weir was more conducive to the tagged fish surviving when released.

In general terms most of the Barramundi deaths occurred when water temperatures dropped to 14-15oC however in these impoundments not all fish died. Only in Lake Callide where the water temperature dropped to 10oC did all fish die.

2 Dr Alan Webb Australian Centre for Tropical Freshwater Research (unpublished)

page 15 Divisison Fish Barramundi Others deaths deaths Gulf of Carpentaria ~3,500 ~2,500 Forktail Catfish, Sleepy (20t) Cod, Sooty Grunter, Bony Bream, Eeltail Catfish, Longtom North Queensland <100 <100 (0.5t) Sooty Grunter Central ~29,420 ~25,120 Bony Bream, Catfish Queensland (176t) Mary/Burnett ~5,300 ~5,000 (25t) Australian Bass, Gudgeon, Eel, Bony Bream, Forktail Catfish and Eeltail Catfish South East Large Not stocked in Tilapia, Bony Bream, Queensland numbers SEQ Forktail Catfish, Eel, but no impoundments Turtle estimate Estimated total >40,000 ~32,720 (221.5t)

Table 1: Estimate of total fish deaths in each geographic division

4. Implications for Future Stocking

While the fish deaths were devastating for some Stocking Groups there were some useful lessons to be learnt with implications for future stocking strategies.

Based on this, and work in Lake Tinaroo3, it suggests that stocking Barramundi, or any other fingerlings, into impoundments where there is already a significant number of large Barramundi is not likely to increase the size of the fishery as most fish are likely to be eaten by the larger Barramundi. This is probably not an effective use of stocking funds. Stocking groups will need to consider what sort of fishery they prefer and develop a stocking regime that will meet their expectations.

In southern impoundments Tilapia numbers have increased significantly in recent years. Based on the large numbers of fish that died they have well established populations in many south eastern Queensland impoundments.

3 Use of a fishery model (FAST) to explain the declines in the stocked Barramundi (Lates calcarifer) (Bloch) fishery in Lake Tinaroo, Australia: AJ McDougall, MG Pearce and M MacKinnon: Lakes and Reservoirs: Research and Management (2008): 13: 125-134

page 16 The interaction between Tilapia and native species in these impoundments is not well known and it is uncertain what impact Tilapia will have on future stocking.

page 17 5. Gulf of Carpentaria Division

Within the Gulf of Carpentaria Division there were 3 impoundments where fish death events were reported. These were:

 Lake Moondarra  Lake Mary Kathleen (East Leichhardt Dam)  Chinaman Creek Reservoir

Table 1 provides a summary of fish death events in this division. It is estimated that about 3,500 fish died including around 2,500 Barramundi, mostly in Lake Moondarra. Based on the fish sizes the estimated average length was around 1,000mm and an estimated average weight of around 8kg. The estimate of the biomass of Barramundi that died is around 20 tonnes.

Impoundment Fish Barramundi Others deaths deaths Lake Moondarra ~2,500 ~2,500 Forktail Catfish, Sleepy Cod Lake Mary Kathleen >1,000 Numbers not Sooty Grunter, Bony recorded Bream, Eeltail Catfish, Longtom Chinaman Creek 20-30 ~20 2-3 different species Reservoir Estimated total ~3,500 ~2,500

Table 2: Summary of fish deaths in impoundments in Gulf of Carpentaria Division

As well as fish that died in the impoundments there were a number of reports from commercial fishers of fish dying in Gulf rivers around the same time however the reports were sketchy and no details were able to be obtained on the extent of the deaths.

page 18 Lake Moondarra

Location: Lake Moondarra on Leichhardt River is located 15km north of Mount Isa Latitude/Longitude: 20o35’S 139o33’E

Daily minimum air temperatures for Mount Isa in July-August 2007 4

18 MOUNT ISA MINIMUM TEMPERATURES 16 MIN TEMP E 14 R MIN AVG U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

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

4 Data obtained from www.bom.gov.au

page 19 Weather data for July-August 2007

Site name: Mount Isa Aero Site number: 029127 Latitude: 20.68oS Longitude: 139.49oE Elevation: 340m Long term July average minimum temperature: 8.6oC July 2007 average minimum temperate: 7.6oC Days below minimum average temperatures in July: 23 (74.2%) Long term August average minimum temperature: 10.3oC August 2007 average minimum temperate: 10.5oC Days below minimum average temperatures in August: 11 (35.5%)

Summary of Fish death event – Lake Moondarra Stocking history Lake Moondarra has been regularly stocked with Sooty Grunter and Barramundi since 1985 5 Date reported First reported on 8/7/2007 Reported by Mount Isa resident Reported to EPA Mount Isa Investigated by EPA on 8/7/2007 Report available EPA Mount Isa 6 Timing of fish death event 8/7/2007-16/7/2007 Species involved Barramundi, Forktail Catfish, Sleepy Cod Numbers of dead fish ~2,500 Barramundi in total 7 other species not recorded Tagged fish recovered 57 tagged fish recovered – 19 without tag details Size range 400-1260mm average size 900-1000mm Water level ~47% in July 8 Water temperature 14-15oC recorded on 27/6/2007 9 Water samples taken Mount Isa Water 10 Results of water samples No abnormalities Presumptive diagnosis Fish most likely died from low water temperatures Comments This was not a completed kill as fish tagged prior to the fish death event were recaptured in November 2007

5 Details of stocking available at www.mountisafish.org.au 6 EPA report reference CR38313 7 Estimate of numbers from Mount Isa Fish Stocking Association 8 Provided by Mount Isa Mines Services 9 Mount Isa Water – Water Quality Monitoring – Weekly Results 10 Mount Isa Water – Water Quality Monitoring – Weekly Results

page 20 Recovery of tagged Fish with length details Tag Tag date Recovered Days Tag L Rec L Growth J77144 29/12/2001 10/7/2007 2019 520 1170 650 J76943 20/1/2002 10/7/2007 1997 580 800 220 P41398 31/10/2004 10/7/2007 982 225 1000 775

Figure 9: Part of the Barramundi that died in Lake Moondarra (Photograph courtesy of Mount Isa Fish Stocking Association)

page 21 Lake Mary Kathleen (East Leichhardt Dam)

Location: Lake Mary Kathleen is on East Leichhardt River 30km east of Mount Isa Latitude/Longitude: 20o47’S 139o47’E

Image from Google Earth

Daily minimum air temperatures for Mount Isa in July-August 2007 11

18 MOUNT ISA MINIMUM TEMPERATURES 16 MIN TEMP E 14 R MIN AVG U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

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

11 Data obtained from www.bom.gov.au

page 22 Weather data for July-August 2007

Site name: Mount Isa Aero Site number: 029127 Latitude: 20.68oS Longitude: 139.49oE Elevation: 340m Long term July average minimum temperature: 8.6oC July 2007 average minimum temperate: 7.6oC Days below minimum average temperatures in July: 23 (74.2%) Long term August average minimum temperature: 10.3oC August 2007 average minimum temperate: 10.5oC Days below minimum average temperatures in August: 11 (35.5%)

Summary of Fish death event – Lake Mary Kathleen Stocking history The lake was first stocked with Sooty Grunter in 2000 Date reported First reported on 5/7/2007 Reported by Mount Isa resident Reported to EPA Mount Isa Investigated by EPA on 6/7/2007 Report available EPA Mount Isa 12 Timing of fish death event 5/7/2007 – 17/7/2007 Species involved Barramundi, Sooty Grunter, Bony Bream, Eeltail Catfish, Longtom Numbers of dead fish >1,000 13 no estimate of Barramundi numbers Tagged fish recovered No fish tagged in this impoundment Size range 20-300mm Water level Water temperature Water samples taken EPA on 6/7/2007 14 Results of water samples No abnormalities Presumptive diagnosis Fish most likely died from low water temperatures

12 EPA report reference CR38314 13 EPA report reference CR38314 14 Water samples analysed by SGS at Cairns

page 23 Chinaman Creek Reservoir

Location: Chinaman Creek Reservoir on Chinaman Creek is at Cloncurry Latitude/Longitude: 20o44’S 140o28’E

Daily minimum air temperatures for Cloncurry in July-August 2007 15

20 CLONCURRY MINIMUM TEMPERATURES 18

16 MIN TEMP

S MIN AVG E

R 14 U T

A 12 P M

E 10 T

U 8 M I

N 6 I M 4

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

15 Data obtained from www.bom.gov.au

page 24 Weather data for July-August 2007

Site name: Cloncurry Aero Site number: 029009 Latitude: 20.67oS Longitude: 140.51oE Elevation: 189m Long term July average minimum temperature: 10.3oC July 2007 average minimum temperate: 9.3oC Days below minimum average temperatures in July: 20 (64.5%) Long term August average minimum temperature: 11.7oC August 2007 average minimum temperate: 12.1oC Days below minimum average temperatures in August: 13 (41.9%)

Summary of Fish death event – Chinaman Creek Reservoir Stocking history Stocking history not currently available Date reported First reported on 9/7/2007 Reported by Mount Isa resident Reported to EPA Mount Isa Investigated by EPA on 9/7/2007 Report available EPA Mount Isa 16 Timing of fish death event 9/7/2007 -17/7/2007 Species involved Barramundi, 2-3 different species, Turtles Numbers of dead fish 20-30 fish 17 3-4 Turtles Tagged fish recovered No fish tagged in this impoundment at time of kill Size range Large - one Barramundi estimated at 1000mm Water level Water temperature Water samples taken Cloncurry Shire Council test water every 3 days 18 Results of water samples No abnormalities Presumptive diagnosis Fish most likely died from low water temperatures

16 EPA report reference CR38312 17 EPA report reference CR38312 18 Water samples analysed by Queensland Health Scientific Services

page 25 6. North Queensland Division

Within the North Queensland Division there were 3 impoundments where fish death events were reported. These were:

 Lake Tinaroo  Lake Teemburra

Table 2 provides a summary of fish death events in this division. It is estimated that ~100 fish were killed and almost all of these were Barramundi. Based on an average length of 800mm and an estimated weight of 5kg this equates to about 0.5 tonne of fish.

Impoundment Fish Barramundi Others deaths deaths Lake Tinaroo <50 <50 Lake Teemburra ~40 ~40 Sooty Grunter Lake Eungella <10 <10 Estimated total ~100 ~100

Table 3: Summary of fish deaths in impoundments in the North Queensland Division These were the only reports of fish death events involving stocked fish in the North Queensland Division. A number of reports were also received of fish deaths that most likely did not involve stocked fish. There were several reports during July from the Broken River and Urannah Creek in the Mackay area. Fish reported included Blue Catfish, Eeltail Catfish and others (not specified).

There was a report on 26/7/2008 investigated by the Bowen Boating and Fisheries Patrol of ~100 dead Barramundi in a ring tank but no further details were available. A number of dead Sleepy Cod were reported on 6/7/2008 from the upper Murray River at Tully. Another report of fish deaths in the Clohesy River was reported to the DPI&F at Mareeba. This involved ~20 Eeltail Catfish.

page 26 Lake Tinaroo Location: Lake Tinaroo on Barron River is located 10km north east of Atherton Latitude/Longitude: 17o12’S 145o35’E

Daily minimum air temperatures for Atherton in July-August 2007 19

20 ATHERTON MINIMUM TEMPERATURES

MIN TEMP 15 MIN AVG S E R U T

A 10 R E P M E T

M 5 U M I N I M

0 7 7 7 7 7 7 7 7 7 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8 0 0 0 0 0 0 0 0 0

-5 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

19 Data obtained from www.bom.gov.au

page 27 Weather data for July-August 2007

Summary of Fish death event – Lake Tinaroo Stocking history From 1985/86 to 2002/03 around 988,000 Barramundi from 25-75mm were stocked into the lake. In 2003/04 and 2004/05 over 12,300 tagged fish averaging 300mm were stocked. 20 Date reported First reported on 9/8/2007 Reported by Reported to Investigated by Not investigated Report available Timing of fish death event 9/8/2007 Species involved Barramundi Numbers of dead fish <50 21 Tagged fish recovered Nil Size range Large fish Water level ~85% 22 Water temperature Lowest water temperature 18oC recorded on 6/8/2007 23 Water samples taken No Results of water samples Presumptive diagnosis

20 DPI&F Fisheries Northern Fisheries Centre 21 Number as reported to DPI&F Northern Fisheries Centre 22 Data from SunWater website www.sunwater.com.au 23 Data from Northern Fisheries Centre Fish Monitoring Team

page 28 Lake Teemburra

Location: Lake Teemburra is 5km south of Finch Hatton Latitude/Longitude: 21o12’S 148o40’E

Daily minimum air temperatures for Mackay MO in July-August 2007 24

MACKAY MO MINIMUM TEMPERATURES

E MIN TEMP R

U MIN AVG T A

R 15 E P M E T

M 10 U M I N I M 5

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

24 Data obtained from www.bom.gov.au

page 29 Weather data for July-August 2007

Site name: Mackay MO Site number: 033119 Latitude: 20.12oS Longitude: 149.22oE Elevation: 30m Long term July average minimum temperature: 12.8oC July 2007 average minimum temperate: 10.5oC Days below minimum average temperatures in July: 25 (80.6%) Long term August average minimum temperature: 14.0oC August 2007 average minimum temperate: 14.6oC Days below minimum average temperatures in August: 11 (35.5%)

Summary of Fish death event – Lake Teemburra Stocking history Stocking commenced in the late 1980s with Barramundi and Sooty Grunter stocked Date reported 17/7/2007 Reported by Reported to EPA Mackay and DPI&F Mackay Investigated by Not investigated Report available Timing of fish death event 17/7/2007 Species involved Barramundi, Sooty Grunter Numbers of dead fish ~40 Barramundi 25 1 Sooty Grunter Tagged fish recovered Nil Size range 700-1250mm 26 Water level ~55% 27 Water temperature 8-14oC in shallow water 28 Water samples taken No Results of water samples Presumptive diagnosis

25 Estimate of number of fish provided by SunWater Mackay 26 Size estimates from summary fish death event report compiled by DPI&F Brisbane 27 Data from SunWater website www.sunwater.com.au 28 Temperature data from summary fish death event report compiled by DPI&F Brisbane

page 30 Lake Eungella

Location: Lake Eungella on Eungella Creek is 10km west of Eungella Latitude/Longitude: 21o09’S 148o24’E

Daily minimum air temperatures for Mackay MO in July-August 2007 29

MACKAY MO MINIMUM TEMPERATURES

E MIN TEMP R

U MIN AVG T A

R 15 E P M E T

M 10 U M I N I M 5

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

29 Data obtained from www.bom.gov.au

page 31 Weather data for July-August 2007

Summary of Fish death event – Lake Eungella Stocking history Stocking commenced in the late 1980s with Barramundi, Sooty Grunter, Sleepy Cod and Saratoga stocked Date reported July 2007 Reported by Reported to DPI&F Mackay Investigated by Not investigated Report available Timing of fish death event July 2007 Species involved Barramundi Numbers of dead fish <10 Barramundi 30 Tagged fish recovered Nil Size range Large Water level ~75% 31 Water temperature Water samples taken No Results of water samples Presumptive diagnosis

30 Estimate of number of fish provided by DPI&F Mackay 31 Data from SunWater website www.sunwater.com.au

page 32 7. Central Queensland Division

Within the Central Queensland Division there were 6 impoundments and waterways where fish death events were reported. These were:

 Baralaba Weir at Baralaba  Moura Weir at Moura  Lake Maraboon at Emerald  Lake Theresa and Hoods Lagoon  Lake Callide  Lake Awoonga

Table 3 provides a summary of fish death events in this division. It is estimated that 29,420 fish were killed and most of these were Barramundi. However other species may have been killed but were not reported due to the focus on Barramundi. Based on the fish sizes the estimated average size was around 900mm and an estimated average weight of around 7kg. The estimate of the biomass of Barramundi that died is around 176 tonnes.

Impoundment Fish Barramundi Others deaths deaths Baralaba Weir ~20 ~20 Moura Weir >2,000 ~200 Bony Bream, Catfish Lake Maraboon ~7,500 ~5,000 Not recorded Lake Theresa ~7,600 ~7,600 Not recorded Lake Callide ~12,000 ~12,000 Not recorded Lake Awoonga ~300 ~300 Not recorded Estimated total 29,420 25,120

Table 4: Summary of fish deaths in impoundments in Central Queensland division

As well as the fish that died in impoundments there were numerous reports of fish deaths in farm dams, particularly in the Gogango and Moura areas.

page 33 Baralaba Weir at Baralaba

Location: Baralaba Weir is on the Dawson River at Baralaba Latitude/Longitude: 24o10’S 149o49’E

Daily minimum air temperatures for Baralaba in July-August 2007 32

18 BARALABA MINIMUM TEMPERATURES 16 BARALABA MIN TEMP 14 E BARALABA MIN AVG R U

T 12 A R E

P 10 M E T 8 M U

M 6 I N I

M 4

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

32 Data obtained from www.bom.gov.au

page 34 Weather data for July-August 2007

Site name: Baralaba Post Office Site number: 039004 Latitude: 24.18oS Longitude: 149.81oE Elevation: 100m Long term July average minimum temperature: 7.4oC July 2007 average minimum temperate: 5.6oC Days below minimum average temperatures in July: 23 (74.2%) Long term August average minimum temperature: 8.7oC August 2007 average minimum temperate: 10.6oC Days below minimum average temperatures in August: 9 (29.0%)

Summary of Fish death event – Dawson River at Baralaba Stocking history Barramundi have been stocked since 2000 with 61,100 released since then. Stocking of Golden Perch was from 1989-1999 with 93,700 released over that time. One stocking of 8,600 Silver Perch occurred in 1989. 33 Date reported 8/8/2007 Reported by Reported to Information on this fish death event was obtained from Robbie Price 34 Investigated by Report available Timing of fish death event 8/8/2007 Species involved Barramundi Numbers of dead fish ~10 Barramundi Tagged fish recovered Nil Size range 800-1000mm Water level ~40% 35 Water temperature Water samples taken No Results of water samples Presumptive diagnosis

33 Stocking details from DPI&F Rockhampton 34 Baralaba Recreation and Fish Stocking Group 35 Data from SunWater website www.sunwater.com.au

page 35 Moura Weir at Moura

Location: Moura Weir is on the Dawson River 7km west of Moura Latitude/Longitude: 24o36’S 149o54’E

Daily minimum air temperatures for Baralaba in July-August 2007 36

18 BARALABA MINIMUM TEMPERATURES 16 BARALABA MIN TEMP 14 E BARALABA MIN AVG R U

T 12 A R E

P 10 M E T 8 M U

M 6 I N I

M 4

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

36 Data obtained from www.bom.gov.au

page 36 Weather data for July-August 2007

Summary of Fish death event – Dawson River at Moura Stocking history Barramundi have been stocked since 2003 with 145,000 fish released. In 2005 and 2006 batches of 600 larger tagged Barramundi were released. Silver Perch, Golden Perch and Sleepy Cod have also been stocked from 1987-2005. 37 Date reported 25/7/2007 Reported by Local resident to EPA Reported to SunWater Biloela Investigated by SunWater Biloela on 26/7/2007 Report available SunWater Biloela 38 Timing of fish death event 25/7/2007-5/8/2007 Species involved Barramundi, Bony Bream, Catfish Numbers of dead fish >2,000 fish including ~200 Barramundi Tagged fish recovered Barramundi 78 ~ 40% of Barramundi killed Size range Bony Bream <100mm, Catfish 400-600mm, Barramundi 161 fish measured 570-1110mm 39 Water level ~90% 40 Water temperature 15oC recorded on 30/7/2007 41 Water samples taken SunWater – fish samples also taken 42 Results of water samples No abnormalities in water samples. In fish samples the disease Chilodonelliasis was suspected in Bony Bream and a range of parasitic (and possibly fungal) infections were involved with all species. Presumptive diagnosis Diseases are associated with low water temperatures and static water in the weir Comments Tagged fish stocked in 2005 and 2006 were recovered in the fish death event (figure 10). The data suggest some loss or overgrowth of tags for fish from those stockings as tags were not detected on some dead fish. Fish from the 2004 stocking were tagged during netting surveys following that stocking.

Not all fish died as there were recaptures in the Fitzroy River at Rockhampton in February 2008 following flooding in the catchment.

37 Stocking details from DPI&F Rockhampton 38 SunWater Biloela report 39 Barramundi length data collected by Moura Apex Fish Stocking Group 40 Data from SunWater website www.sunwater.com.au 41 SunWater Biloela report 42 Fish samples analysed by Tropical and Aquatic Animal Health Laboratory

page 37 60 2006 stocking MOURA WEIR BARRAMUNDI 50 ALL FISH TAGGED FISH H S I 40 F

F 2005 stocking 2004 stocking O 30 R E B

M 20 U N 10

0 9 9 9 9 9 9 9 9 9 9 9 9 9 4 9 4 9 4 9 4 9 4 9 4 5 6 6 7 7 8 8 9 9 0 0 1 : : : : : : : : : 1 1 1 0 0 0 0 0 0 0 0 0 : : : 5 0 5 0 5 0 5 0 5 0 0 0 5 6 6 7 7 8 8 9 9 0 5 0 0 0 1 1 1 1 SIZE RANGES

Figure 10: Barramundi sizes in Moura Weir fish death event showing fish from different stockings

Figure 11: Dead fish (mostly Bony Bream) and floating scum in Moura Weir (photograph courtesy of SunWater Biloela)

page 38 Lake Maraboon

Location: Lake Maraboon is on the Nogoa River 15km south west of Emerald Latitude/Longitude: 23o40’S 148o00’E

Daily minimum air temperatures for Emerald in July-August 2007 43

18 EMERALD MINIMUM TEMPERATURES 16

14 MIN TEMP E

R MIN AVG U

T 12 A R E

P 10 M E T 8 M U M

I 6 N I

M 4

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

43 Data obtained from www.bom.gov.au

page 39 Weather data for July-August 2007

Summary of Fish death event – Lake Maraboon Stocking history 30,000 Barramundi fingerlings have been stocked into the lake since 2000 44 Date reported 1/7/2007 Reported by Reported to SunWater Biloela Investigated by SunWater Biloela Report available SunWater Biloela 45 Timing of fish death event 1/7/2007-9/8/2007 Species involved Barramundi, other species not recorded Numbers of dead fish ~2,500 Picnic area and dam wall area only ~5,000 Barramundi Tagged fish recovered Some tagged fish were recovered 46 Size range Barramundi generally over 750mm Water level ~23% 47 Water temperature Minimum temperature of 14.7oC on 10/7/2007 48 Water samples taken SunWater Bileola 49 Results of water samples No abnormalities Presumptive diagnosis Comments While some tagged fish were recovered there are no records of Suntag tags being used in this impoundment and the origin of tags is unknown. 50

44 DPI&F District Fisheries Advisor Shaun Pobar 45 SunWater Biloela report 46 Advice from Gladstone Area Water Board Hatchery 47 Data from SunWater website www.sunwater.com.au 48 SunWater Biloela report 49 SunWater Biloela report 50 Gladstone Area Water Board Hatchery

page 40 Lake Theresa and Hoods Lagoon

Location: Lake Theresa and Hoods Lagoon are on Theresa Creek is 12km south west of Clermont Latitude/Longitude: 22o59’S 147o33’E

Daily minimum air temperatures for Emerald in July-August 2007 51

18 EMERALD MINIMUM TEMPERATURES 16

14 MIN TEMP E

R MIN AVG U

T 12 A R E

P 10 M E T 8 M U M

I 6 N I

M 4

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

51 Data obtained from www.bom.gov.au

page 41 Weather data for July-August 2007

Summary of Fish death event – Lake Theresa and Hoods Lagoon Stocking history Stocking of Barramundi commenced in 2002 with 46,500 released since then. Sleepy Cod, Golden Perch, Bony Bream, Silver Perch, Saratoga and Eeltail Catfish were stocked from 1983-2003 52 Date reported 11/7/2007 Reported by Reported to DPI&F Rockhampton Investigated by DPI&F Rockhampton Report available DPI&F summary of numbers and sizes 53 Timing of fish death event 11/7/2007-13/8/2007 Species involved Barramundi, other species not recorded Numbers of dead fish ~7,600 Barramundi 54 Tagged fish recovered Nil Size range 500-800mm with largest fish ~1120mm Water level ~90% 55 Water temperature 13oC on 13/7/2007 – 12oC on 22/7/2007 56 Water samples taken No Results of water samples Presumptive diagnosis Fish most likely died from low water temperatures

52 Stocking details from Clermont Fish Stocking Group 53 DPI&F District Fisheries Advisor Shaun Pobar 54 DPI&F District Fisheries Advisor Shaun Pobar 55 Data from Clermont Water Treatment Plant 56 DPI&F District Fisheries Advisor Shaun Pobar

page 42 Lake Callide

Location: Lake Callide on Callide Creek is 12km east of Biloela Latitude/Longitude: 24o22’S 150o38’E

Daily minimum air temperatures for Thangool in July-August 2007 57

18 THANGOOL MINIMUM TEMPERATURES 16 MIN TEMP 14 MIN AVG 12 E R U

T 10 A R E

P 8 M E T 6 M U M

I 4 N I

M 2

0 7 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 0 0 0 0 -2 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-4 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

57 Data obtained from www.bom.gov.au

page 43 Weather data for July-August 2007

Site name: Thangool Airport Site number: 039089 Latitude: 24.49oS Longitude: 150.57oE Elevation: 192m Long term July average minimum temperature: 5.4oC July 2007 average minimum temperate: 2.8oC Days below minimum average temperatures in July: 25 (80.6%) Long term August average minimum temperature: 6.4oC August 2007 average minimum temperate: 8.3oC Days below minimum average temperatures in August: 8 (25.8%)

Summary of Fish death event – Lake Callide Stocking history Lake Callide has been stocked with over 404,000 Golden Perch since 1988 and 14,000 Sleepy Cod since 1992. Barramundi were first stocked in 1999 and 200,000 fish have been stocked to 2007 prior to the fish death event.58 Date reported 7/7/2007 Reported by Reported to SunWater Biloela Investigated by SunWater Biloela Report available Timing of fish death event 7/7/2007-8/8/2007 Species involved Barramundi, other species not recorded Numbers of dead fish ~12,000 Barramundi 59 Tagged fish recovered 2 Size range 700-1200mm with largest fish 1350mm Water level 8% Water temperature Water temperature was below 15oC for all of July with a low of 10oC from 18-20/7/2007 60 Water samples taken Blue-green algae test 61 Results of water samples Blue-green algae not considered an issue in the fish death event Presumptive diagnosis Fish most likely died from low water temperatures Comments A batch of 600 tagged fish ~200mm was released in 2005 with only 1 fish recovered in the fish death event. As the lake contained many large Barramundi it is possible that there was a significant level of cannibalism leading to low survival of fish from that release. This appears to have been a total fish death event of Barramundi as no fish have been recorded since the fish death event.

Recovery of tagged Fish Tag Tag date Recovered Days Tag L Rec L Growth P51650 22/11/2004 17/7/2007 967 1010 1260 250 P63022 28/1/2005 17/7/2007 900 200 660 460

58 Callide Valley Native Fish Stocking Association 59 Estimate by SunWater Biloela 60 SunWater Daily Monitoring of Water Evaporation 61 Blue-green algae samples analyses by SunWater Biloela

page 44 Figure 12: Fish death event in Lake Callide (Photographs courtesy of John Barber SunWater Biloela)

page 45 Lake Awoonga

Location: Lake Awoonga is on Boyne River is 15km south east of Calliope Latitude/Longitude: 24o05’S 151o18’E

Image from Google Earth

Daily minimum air temperatures for Gladstone in July-August 2007 62

20 GLADSTONE MINIMUM TEMPERATURES 18 MIN TEMP 16

E MIN AVG R

U 14 T A

R 12 E P M

E 10 T

M 8 U M I

N 6 I M 4

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

62 Data obtained from www.bom.gov.au

page 46 Weather data for July-August 2007

Site name: Gladstone Radar Site number: 039123 Latitude: 23.86oS Longitude: 151.26oE Elevation: 75m Long term July average minimum temperature: 13.3oC July 2007 average minimum temperate: 9.3oC Days below minimum average temperatures in July: 27 (87.1%) Long term August average minimum temperature: 14.3oC August 2007 average minimum temperate: 13.6oC Days below minimum average temperatures in August: 17 (54.8%)

Summary of Fish death event – Lake Awoonga Stocking history Fish have been stocked in Lake Awoonga since the 1980s. Since 1996 the lake has been stocked with 2,445,348 Barramundi, 471,608 Sea Mullet, 78,003 Yellowfin Bream, 13,042 Mangrove Jack and 52 Saratoga. 63 Date reported 8/8/2007 Reported by Reported to Gladstone Area Water Board Hatchery Investigated by Gladstone Area Water Board Hatchery Report available Yes Timing of fish death event 8/8/2007 Species involved Barramundi, other species not recorded Numbers of dead fish ~300 64 Tagged fish recovered Nil Size range Most fish were 1,000-1,100mm 65 Water level ~35% 66 Water temperature 14oC in shallows around weedbeds Water samples taken Yes Results of water samples Presumptive diagnosis Fish most likely died from low water temperatures Comments Most dead fish were located in the shallows around the weedbeds

63 Stocking details from Fisheries Management Plan for Lake Awoonga 2007-2013 64 Gladstone Area Water Board Hatchery 65 Gladstone Area Water Board Hatchery 66 Water level from Gladstone Area Water Board website www.gawb.qld.gov.au

page 47 8. Mary/Burnett Division

Within the Mary/Burnett Division there were 4 impoundments and waterways where fish death events were reported. These were:

 Lake Monduran  Lake Lenthall  Burnett River at Gayndah  Lake Borumba

Table 3 provides a summary of fish death events in this division. It is estimated that 6,500 fish died and most of these were Barramundi. However other species may have died but were not reported due to the focus on Barramundi. Based on the fish sizes the estimated average size was around 800mm which equates to around 5kg. The estimate of the biomass of Barramundi that died is around 25 tonnes.

Impoundment Fish Barramundi Others deaths deaths Lake Monduran ~100 ~100 Lake Lenthall ~5,000 4-5,000 ~60 Australian Bass, Gudgeon, Eel, Bony Bream, Catfish Burnett River at ~200 ~160 Forktail Catfish, Gayndah Eeltail Catfish, Bony Bream Lake Borumba 900-1,500 Gudgeon, Saratoga Estimated totals ~6,500 ~5,000

Table 5: Summary of fish deaths in impoundments and waterways in the Mary/Burnett Division

There were a number of other fish deaths reported including in the Mary River at Widgee Crossing and in Obi Obi Creek below Lake Baroon.

page 48 Lake Monduran

Location: Lake Monduran on the Kolan River is 15km north west of Gin Gin Latitude/Longitude: 24o48’S 151o48’E

Daily minimum air temperatures for Bundaberg in July-August 2007 67

20 BUNDABERG MINIMUM TEMPERATURES 18 MIN TEMP 16

E MIN AVG R

U 14 T A

R 12 E P M

E 10 T

M 8 U M I

N 6 I M 4

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

67 Data obtained from www.bom.gov.au

page 49 Weather data for July-August 2007

Site name: Bundaberg Aero Site number: 039128 Latitude: 24.89oS Longitude: 152.32oE Elevation: 27m Long term July average minimum temperature: 10.1oC July 2007 average minimum temperate: 8.2oC Days below minimum average temperatures in July: 14 (45.2%) Long term August average minimum temperature: 10.9oC August 2007 average minimum temperate: 12.7oC Days below minimum average temperatures in August: 12 (38.7%)

Summary of Fish death event – Lake Monduran Stocking history Stocking history currently not available Date reported 9/8/2007 Reported by Reported to Investigated by Report available Timing of fish death event 8/8/2007 Species involved Barramundi, other species not recorded Numbers of dead fish ~100 Tagged fish recovered Nil Size range No recorded Water level 20% Water temperature Water samples taken No Results of water samples Presumptive diagnosis The fish deaths were in the mid reaches of the lake and it was considered that the deaths could have been the result of the dam rolling over in that area rather than low water temperatures. 68 Comments There was not a reliable estimate of the numbers of fish that died as due to the small numbers there was no formal investigation undertaken.

68 Department of Primary Industries and Fisheries Bundaberg

page 50 Lake Lenthall

Location: Lake Lenthall on Burrum River is 10km south west of Howard Latitude/Longitude: 25o23’S 152o30’E

Image from Google Earth

Daily minimum air temperatures for Maryborough in July-August 2007 69

20 MARYBOROUGH MINIMUM TEMPERATURES 18

16 MIN TEMP MIN AVG

E 14 R U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

0 7 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 0

-2 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 / / / / / / / / / 7 7 7 7 7 8 8 8 8 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

69 Data obtained from www.bom.gov.au

page 51 Weather data for July-August 2007

Site name: Maryborough Site number: 040126 Latitude: 25.52oS Longitude: 152.72oE Elevation: 10m Long term July average minimum temperature: 8.6oC July 2007 average minimum temperate: 5.4oC Days below minimum average temperatures in July: 24 (77.4%) Long term August average minimum temperature: 9.3oC August 2007 average minimum temperate: 11.0oC Days below minimum average temperatures in August: 10 (32.2%)

Summary of Fish death event – Lake Lenthall Stocking history Stocking of Australian Bass commenced in 1991 with 432,000 fish released since then. Stocking of Silver Perch was from 1992-2000 with 92,500 fish released. Stocking of Barramundi commenced in 1997 with 40,900 fish released. Date reported 6/8/2007 Reported by Reported to Investigated by Fraser Coast Fish Stocking Association Wide Bay Water Corporation Report available Timing of fish death event 15/7/2007-15/8/2007 Species involved Barramundi, Australian Bass, Gudgeons, Eels, Bony Bream, Catfish Numbers of dead fish 4-5,000 Barramundi 70, ~30 Australian Bass, ~20 Bony Bream, ~10 Longfin Eel 71 Tagged fish recovered 7 Barramundi Size range All sizes with largest fish over 1000mm Water level 50%72 Water temperature For month of July 13.9-15.4oC 73 Water samples taken No Results of water samples Presumptive diagnosis Fish most likely died from low water temperatures

Recovery of tagged fish Tag Tag date Recovered Days Tag L Rec L Growth J64340 3/11/2005 1/8/2007 636 415 650 235 R70293 31/1/2007 1/8/2007 182 595 J64323 28/10/2005 3/8/2007 644 490 700 210 R18853 18/11/2005 15/7/2007 604 440 620 180 R18854 18/11/2005 1/8/2007 621 470 800 330 R49044 4/10/2006 1/8/2007 301 430 550 120 R49019 29/10/2006 1/8/2007 276 420 550 130

70 Estimate for Barramundi provided by Paul Dolan of Fraser Coast Fish Stocking Association 71 Estimate for other species provided by Wide Bay Water Corporation 72 Provided by Wide Bay Water Corporation 73 Provided by Wide Bay Water Corporation

page 52 Figure 13: Dead Barramundi at Lake Lenthall (Paul Dolan photographs)

page 53 Burnett River Gayndah to Grays Waterhole

Location: Below Claude Wharton Weir at Gayndah and between Gayndah and Grays Waterhole Latitude/Longitude: 25o32’S to 25o37’S and 151o36’E to 151o39’E

Grays Waterhole

Claude Wharton Weir

Daily minimum air temperatures for Maryborough in July-August 2007 74

20 MARYBOROUGH MINIMUM TEMPERATURES 18

16 MIN TEMP MIN AVG

E 14 R U T

A 12 R E

P 10 M E T

8 M U

M 6 I N I 4 M

0 7 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 0

-2 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 / / / / / / / / / 7 7 7 7 7 8 8 8 8 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

74 Data obtained from www.bom.gov.au

page 54 Weather data for July-August 2007

Summary of fish death event – Burnett River at Gayndah Stocking history Stocking history currently not available Date reported 2/7/2007 Reported by Local landholder Reported to EPA Wide Bay/Burnett Investigated by EPA Wide Bay/Burnett Report available EPA Maryborough 75 Timing of fish death event 2/7/2007 Species involved Barramundi, Catfish Numbers of dead fish ~20 mostly Barramundi and a couple of smaller Catfish Tagged fish recovered Nil Size range Large fish Water level Water temperature 15.9oC on 3/7/2007 Water/fish samples taken EPA Wide Bay/Burnett Results of tests Water samples - no abnormalities Fish samples – no modern pesticides detected 76 Presumptive diagnosis

Figure 14: Dead Barramundi in the Burnett River downstream from Gayndah (Photograph courtesy of EPA Marybough)

75 EPA report reference CR38277 76 Fish samples tested by Queensland Health

page 55 Summary of fish death event – Burnett River between Gayndah and Grays Waterhole Stocking history Stocking history currently not available Date reported 11/7/2007 Reported by Reported to DPI&F Investigated by Report available Timing of fish death event 11/7/2007 Species involved Barramundi, Forktail Catfish, Bony Bream, Eeltail Catfish Numbers of dead fish ~140 Barramundi , 28 Forktail Catfish, 1 Bony Bream, 1 Eeltail Catfish 77 Tagged fish recovered 8 tagged fish (no details) Size range 4 Barramundi @ approximately 800, most 400- 550mm 78 Water level Water temperature Water/fish samples taken Results of tests Presumptive diagnosis

Figure 15: Close up of dead Barramundi in Burnett River (photograph courtesy of EPA Maryborough)

77 DPI&F summary report 78 DPI&F summary report

page 56 Lake Borumba

Location: Lake Borumba on Yabba Creek is 10km west of Imbil Latitude/Longitude: 26o31’S 152o34’E

Daily minimum air temperatures for Gympie in July-August 2007 79

GYMPIE MINIMUM TEMPERATURES

15 MIN TEMP MIN AVG

0 7 7 7 7 7 7 7 7 7 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-5 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

-10

79 Data obtained from www.bom.gov.au

page 57 Weather data for July-August 2007

Site name: Gympie Site number: 040093 Latitude: 26.18oS Longitude: 152.64oE Elevation: 65m Long term July average minimum temperature: 6.2oC July 2007 average minimum temperate: 2.2oC Days below minimum average temperatures in July: 26 (83.9%) Long term August average minimum temperature: 7.1oC August 2007 average minimum temperate: 8.0oC Days below minimum average temperatures in August: 14 (45.2%)

Summary of fish death event – Lake Borumba Stocking history Stocking history currently not available Date reported 31/7/2007 Reported by Reported to EPA Maryborough Investigated by Report available Timing of fish death event 9/7/2007 – 31/7/2007 Species involved Gudgeon and Saratoga Numbers of dead fish 900-1,500 mostly gudgeons and a small number of Saratoga 80 Tagged fish recovered Nil Size range Water level ~40% Water temperature 13-14oC Water/fish samples taken No Results of tests Presumptive diagnosis Cold temperatures and lake turnover Comments Estimates were very sketchy with numbers being the general consensus

80 Reported by Gary Sturdy ANSA Qld

page 58 9. South East Queensland Division

Within the South East Queensland Division there are 6 impoundments and waterways where fish deaths were recorded. These are:

 Caboolture River  Lake Samsonvale  Lake Kurwongbah  Lake Somerset  Lake Wivenhoe  Lake Moogerah

Impoundment Fish Australian Others deaths Bass deaths Caboolture River Large <5 Mostly Tilapia numbers Lake Samsonvale 1000s Mostly Tilapia, also Bony Bream, Eel, Turtle Lake Kurwongbah No estimate Mostly Tilapia, also Eel, Turtle Lake Somerset Large Tilapia, Bony Bream, numbers Eel, Turtle but no estimate Lake Wivenhoe Large Forktail Catfish, numbers Tilapia, Turtle but no estimate Lake Moogerah Low Bony Bream, numbers Spangled Perch Estimated total No overall Low estimate numbers

Table 6: Summary of fish deaths in impoundments and waterways of South East Queensland

A request for further information on the fish death was made to SEQ Water in relation to the impoundments under its control in South East Queensland. However due to legal considerations SEQ Water was unable to provide any information. It was therefore necessary to use the best available anecdotal information to provide some assessment of the extent of fish deaths.

The largest numbers of fish that died in this division were Tilapia which are introduced species and are classed as noxious and must be killed if caught. The number of native fish species that died was much smaller. It is therefore considered that the fish deaths in this division may have been beneficial in the removal of large numbers of a pest species rather than being detrimental.

page 59 Caboolture River upstream from weir

Location: Caboolture Weir on Caboolture River at Caboolture Latitude/Longitude: 27o05’S 152o57’E

Image from Google Earth

Daily minimum air temperatures for Brisbane in July-August 2007 81

18 BRISBANE MINIMUM TEMPERATURES 16 MIN TEMP 14 MIN AVG

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

81 Data obtained from www.bom.gov.au

page 60 Weather data for July-August 2007

Site name: Brisbane AERO Site number: 040223 Latitude: 27.42oS Longitude: 153.11oE Elevation: 4m Long term July average minimum temperature: 9.5oC July 2007 average minimum temperate: 8.3oC Days below minimum average temperatures in July: 23 (74.2%) Long term August average minimum temperature: 10.0oC August 2007 average minimum temperate: 11.4oC Days below minimum average temperatures in August: 10 (32.2%)

Summary of fish death event – Caboolture River Stocking history Stocking history currently not available Date reported 4/7/2007 Reported by Reported to Investigated by Caboolture Shire Council and EPA Sunshine Coast Report available Yes 82 Timing of fish death event 4/7/2007-20/7/2008 Species involved Mostly Tilapia <5 Australian Bass Numbers of dead fish Large numbers Tagged fish recovered Size range Tilapia were 15-40cm Water level Water temperature Water/fish samples taken Yes Results of tests Fish and water analysis results indicated no presence of modern pesticides Presumptive diagnosis Cold weather suspected to be the cause of the fish deaths

82 EPA report reference CR38300 and CR38440

page 61 Lake Samsonvale

Location: Lake Samsonvale on North Pine River at Petrie Latitude/Longitude: 27o17’S 152o54’E

Daily minimum air temperatures for Brisbane in July-August 2007 83

18 BRISBANE MINIMUM TEMPERATURES 16 MIN TEMP 14 MIN AVG

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

83 Data obtained from www.bom.gov.au

page 62 Weather data for July-August 2007

Summary of fish death event – Lake Samsonvale Stocking history Stocking history currently not available Date reported Reported by Reported to Investigated by Report available Timing of fish death event 9/7/2007-21/7/2007 Species involved Mostly Tilapia with other species including Bony Bream, Eel, Eeltail Catfish, Turtle Numbers of dead fish 1000s of Tilapia no estimate of other species with 1 Eeltail Catfish 84 Tagged fish recovered No Size range Water level ~15% Water temperature 11-12oC Water/fish samples taken Results of tests Presumptive diagnosis Comments Forgan Cove and Bullocky Rest on the eastern side of the lake where it is shallow were most affected

84 Estimates and other information provided by Gary Sturdy ANSA Qld

page 63 Lake Kurwongbah

Location: Lake Kurwongbah on Sideling Creek at Kurwongbah Latitude/Longitude: 27o15’S 152o58’E

Image from Google Earth

Daily minimum air temperatures for Brisbane in July-August 2007 85

18 BRISBANE MINIMUM TEMPERATURES 16 MIN TEMP 14 MIN AVG

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

85 Data obtained from www.bom.gov.au

page 64 Weather data for July-August 2007

Summary of fish death event – Lake Kurwongbah Stocking history Stocking history currently not available Date reported Reported by Reported to Investigated by Report available Timing of fish death event 9/7/2007-21/7/2007 Species involved Mostly Tilapia with Eel and Turtle Numbers of dead fish No estimate of numbers 86 Tagged fish recovered No Size range Water level ~12% Water temperature 12-13oC Water/fish samples taken Results of tests Presumptive diagnosis Comments Mostly in the Scouts Road to Torrens Road area

86 Estimates and other information provided by Gary Sturdy ANSA Qld

page 65 Lake Somerset

Location: Lake Somerset on Stanley River is south of Kilcoy Latitude/Longitude: 27o17’S 152o54’E

Daily minimum air temperatures for Amberley in July-August 2007 87

AMBERLEY MINIMUM TEMPERATURES

15 MIN TEMP MIN AVG E R

U 10 T A R E P M

E 5 T

M U M I

N 0 I 7 7 7 7 7 7 7 7 7 M 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-5 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

-10

87 Data obtained from www.bom.gov.au

page 66 Weather data for July-August 2007

Summary of fish death event – Lake Somerset Stocking history Stocking of Lake Somerset commenced in 1988 and since then has been stocked with 963,523 Golden Perch, 757,777 Silver Perch, 398,855 Australian Bass, 8,824 Murray Cod and 319 Southern Saratoga88 Date reported Reported by Reported to Investigated by Report available Timing of fish death event 9/7/2007-21/7/2007 Species involved Mostly Tilapia with Bony Bream, Eel, Turtle Numbers of dead fish Large numbers but no estimate 89 Tagged fish recovered Nil Size range Water level ~28% Water temperature 11.5-13oC Water/fish samples taken Results of tests Presumptive diagnosis

88 Stocking history to 1999 from http://www.marinews.com 89 Estimates and other information provided by Gary Sturdy ANSA Qld

page 67 Lake Wivenhoe

Location: Lake Wivenhoe on Brisbane River is 10km north of Lowood Latitude/Longitude: 27o18’S 152o33’E

Daily minimum air temperatures for Amberley in July-August 2007 90

AMBERLEY MINIMUM TEMPERATURES

15 MIN TEMP MIN AVG E R

U 10 T A R E P M

E 5 T

M U M I

N 0 I 7 7 7 7 7 7 7 7 7 M 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-5 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

-10

90 Data obtained from www.bom.gov.au

page 68 Weather data for July-August 2007

Summary of fish death event – Lake Wivenhoe Stocking history Stocking history currently not available Date reported Reported by Reported to Investigated by Report available Timing of fish death event 9/7/2007-21/7/2007 Species involved Forktail Catfish, Tilapia, Turtle Numbers of dead fish Large numbers but no estimate 91 Tagged fish recovered Nil Size range Water level ~13% Water temperature 11.5-13oC Water/fish samples taken Results of tests Presumptive diagnosis Comments Billy Bay and Platypus Bay were severely affected

91 Estimates and other information provided by Gary Sturdy ANSA Qld

page 69 Lake Moogerah

Location: Lake Moogerah on Reynolds Creek is 15km south west of Boonah Latitude/Longitude: 28o25’S 152o33’E

Daily minimum air temperatures for Amberley in July-August 2007 92

AMBERLEY MINIMUM TEMPERATURES

15 MIN TEMP MIN AVG E R

U 10 T A R E P M

E 5 T

M U M I

N 0 I 7 7 7 7 7 7 7 7 7 M 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 / / / / / / / / / 7 7 7 7 7 8 8 8 8

-5 0 0 0 0 0 0 0 0 0 / / / / / / / / / 1 8 5 2 9 5 2 9 6 1 2 2 1 1 2

-10

92 Data obtained from www.bom.gov.au

page 70 Weather data for July-August 2007

Summary of fish death event – Lake Moogerah Stocking history Stocking history currently not available Date reported Reported by Reported to Investigated by Report available Timing of fish death event 9/7/2007-21/7/2007 Species involved Bony Bream, Spangled Perch Numbers of dead fish Low numbers 93 Tagged fish recovered Nil Size range Water level ~3% Water temperature 10.5-11.5oC Water/fish samples taken Results of tests Presumptive diagnosis Comments Fish deaths were minimal however there were a large number of deaths when the lake filled in November 2007

93 Estimates and other information provided by Gary Sturdy ANSA Qld

page 71