TRANSLOCATED FISHES IN STREAMS OF THE WET TROPICS REGION, NORTH QUEENSLAND Distribution and Potential Impact Damien W. Burrows Established and supported under the Australian Cooperative Research Centres Program © Cooperative Research Centre for Tropical Rainforest Ecology and Management. ISBN 0 86443 710 2 This work is copyright. The Copyright Act 1968 permits fair dealing for study, research, news reporting, criticism or review. Selected passages, tables or diagrams may be reproduced for such purposes provided acknowledgement of the source is included. Major extracts of the entire document may not be reproduced by any process without written permission of the Chief Executive Officer, Cooperative Research Centre for Tropical Rainforest Ecology and Management. Published by the Cooperative Research Centre for Tropical Rainforest Ecology and Management. Further copies may be requested from the Cooperative Research Centre for Tropical Rainforest Ecology and Management, James Cook University, PO Box 6811, Cairns, QLD, Australia 4870. This publication should be cited as: Burrows, D. W. (2004) Translocated Fishes in Streams of the Wet Tropics Region, North Queensland: Distribution and Potential Impact. Cooperative Research Centre for Tropical Rainforest Ecology and Management. Rainforest CRC, Cairns (83pp). February 2004 Translocated Fishes in Streams of the Wet Tropics Region CONTENTS EXECUTIVE SUMMARY ........................................................................................................iii 1.0 INTRODUCTION.............................................................................................................1 1.1 History of Fish Stocking .........................................................................................1 1.2 Exotic Versus Translocated Fishes .......................................................................4 1.3 Recognition of the Importance of Native Fish Translocations ...............................5 1.4 Impacts of Translocated Native Fishes..................................................................6 1.5 Management of Fish Stocking in Queensland .......................................................8 1.6 Commonly Stocked Fish........................................................................................9 2.0 FISH STOCKING ACTIVITIES IN THE WET TROPICS ..............................................11 2.1 Aquatic Values of the Wet Tropics.......................................................................11 2.2 Lake Eacham Rainbowfish – An Example of the Impact of Fish Translocations.11 3.0 WET TROPICS CATCHMENTS AFFECTED BY FISH STOCKING............................14 3.1 Burdekin Catchment............................................................................................14 3.2 Herbert Catchment ..............................................................................................16 3.3 Attie Creek...........................................................................................................18 3.4 Tully Catchment...................................................................................................18 3.5 Liverpool Creek and Maria Creek Catchments....................................................20 3.6 Johnstone Catchment..........................................................................................20 3.7 Barron Catchment................................................................................................21 3.7.1 Tinaroo Dam..........................................................................................23 3.7.2 Crater Lakes..........................................................................................29 3.7.3 Barron River between Barron Falls and Tinaroo Dam ...........................31 3.8 Freshwater Creek Catchment..............................................................................32 3.9 Mitchell Catchment..............................................................................................32 3.10 Bloomfield Catchment..........................................................................................32 3.11 Annan Catchment................................................................................................33 3.12 Lowland Freshwater Streams ..............................................................................33 3.13 Estuarine Stocking...............................................................................................34 3.14 Red Claw Crayfish ...............................................................................................36 4.0 OTHER STOCKING-RELATED ISSUES .....................................................................41 4.1 Numbers of Fish Stocked ....................................................................................41 4.2 Farms, Dams and Aquaculture ............................................................................41 4.3 Effects on Waterbirds..........................................................................................41 4.4 Effects on Frogs...................................................................................................42 4.5 Effects on Aquatic Invertebrates..........................................................................43 4.6 Effects on Ecosystem Processes ........................................................................44 4.7 Genetic Effects....................................................................................................45 4.8 Pathogens and Parasites.....................................................................................48 5.0 INDIRECT EFFECTS OF ENHANCED FISHING EFFORT .........................................50 5.1 Water Quality.......................................................................................................50 i Damien W. Burrows 5.2 Spread of Pest Macrophytes and Animals...........................................................50 6.0 CONCLUSIONS............................................................................................................52 7.0 KEY RESEARCH AND MANAGEMENT RECOMMENDATIONS ...............................60 8.0 REFERENCES .............................................................................................................64 APPENDICES........................................................................................................................76 Appendix A: Fish Species Mentioned on Several Occasions in the Text.....................76 Appendix B: List of Personal Communications ............................................................77 ii Translocated Fishes in Streams of the Wet Tropics Region EXECUTIVE SUMMARY Native fishes do not occur throughout all river systems in Australia. Even within the one river, they may be restricted to certain sections. This is particularly so where barriers such as waterfalls limit the upstream distribution of fishes. Streams above waterfalls typically have a depauperate fish fauna. This is especially true for upland streams of the Wet Tropics. However, for a variety of reasons, but most commonly to create recreational fisheries in these streams, many native fish species have been moved (translocated) to above waterfalls in the Wet Tropics. The potential environmental impacts associated with translocation of native fishes have received very little attention, especially when compared to exotic species. However the two are analogous. Any fish, regardless of its origin, moved to a new stream where it does not naturally occur, may cause significant environmental changes. Translocations have been occurring in the Wet Tropics for around 100 years, mostly done by private individuals and involving low numbers of fish. However, the Recreational Fishing Enhancement Program, a DPI initiative which began in 1986, and the development of mass- hatchery techniques in the last 20 years, has greatly increased the number of fishes stocked. Over 30 million fish have now been stocked in Queensland under this program, including 2 million into waters of the Wet Tropics. Fish that do not naturally occur in the Wet Tropics also enter streams here after escape from farm dams and aquaculture facilities where they are commonly stocked, or via release from aquaria. Evidence is found to suggest that up to 36 freshwater fish species plus red claw crayfish have been translocated into waters of the Wet Tropics. Many of these translocations have resulted in non-locally native species becoming established in the Wet Tropics World Heritage Area and a number of National Parks. These translocations are a combination of farm dam/aquaculture escapes; unofficial/illegal stockings by private individuals; and official stockings by government fisheries agencies. Addressing the issue of translocated fishes in the WTWHA will require a variety of management and planning methods. Despite the extent of stockings that have occurred to date, and the important faunal components of Wet Tropics streams that are considered to be vulnerable to predation by novel fish predators, no environmental evaluations for fish stocking have been undertaken in the Wet Tropics. The distribution of translocated fishes within streams of the Wet Tropics is not adequately known, nor is the extent of overlap between translocated fishes and potentially vulnerable species such as frogs and crustaceans. Translocations of native fish (and other aquatic organisms) are not accounted for in the WTWHA Management Plan, but need to be included. Translocations of fishes