Tilapia found in Walsh River Catchment at Eureka Creek & Removed
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Tilapia such as this specimen were found in the Walsh River Catchment |
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During a DPI Fisheries periodic surveillance in January 2008, Tilapia were discovered in Eureka Creek, a tributary of the Walsh River and in the Mitchell River Catchment. Seven juvenile Tilapia mariae were caught. Subsequent monitoring found more specimens in the vicinity of the initial discovery site.
“This is a nightmare for Mitchell River Watershed Management Group,” said Hilary Kuhn MRWMG Chairperson at the time of discovery of these pest fish. “We have worked very hard for over ten years on the establishment of regular surveillance, the installation of Tilapia exclusion screens in the Mareeba Dimbulah Irrigation Area and education on Tilapia and its possible impacts. So to find a population in the catchment is very distressing news and should be a grave concern for recreational fishers and for the commercial Gulf fishery .”
Tilapia, a highly invasive African species and as much a threat in our waterways as rabbits on land, are a declared noxious fish species in Queensland and there are heavy fines of up to $150,000 for their possession. Tilapia were popular, both as an ornamental fish and in aquaculture, due to their resilience and rapid reproduction and growth rates. Tilapia rapidly degrade aquatic habitats, they can easily out compete native species and their tolerance of salinity means that they can readily exit rivers through estuaries and travel in marine areas to enter other river systems.
“With Wet Season floods, Tilapia could easily be flushed down the Mitchell River to the Gulf,” continued Hilary Kuhn. “Then Tilapia could move from the Mitchell River estuaries to other catchments through coastal waters. This could be a march akin to the cane toad and Tilapia could eventually infest catchments all the way to Arnhem Land with huge impacts on the fishery.”
After more monitoring in Eureka Creek, and consultation with irrigators, Sunwater, traditional owners and other interested parties, an eradication plan was developed. This involved:
- isolating a 5 kilometre length of Eureka Creek and stopping irigation flows;
- extensive electrofishing to remove as many native fish as possible for return to the stream outside the isolation zone;
- poisoning of all fish left in the exclusion zone with rotenone (a readily biodegradable natural fish poison);
- testing of the residual rotenone level and removal of stream barriers when this was safe.
The attached powerpoint presentation is all about the Tilapia eradication campaign carried out in Eureka Creek in October 2008 and the successful return of native species. Some 30 Tilapia of various ages were recovered from the stream following the rotenone treatment and ongoing monitoring will detect any recurrence of Tilapia in this stream or its appearance in other streams in the catchment. Community awareness is an important aspect to controlling Tilapia and MRWMG and DPI Fisheries will continue to distribute information to people in the area.
“It is difficult for people to identify Tilapia,” stated Brynn Mathews MRWMG Projects Officer. “Juveniles are particularly difficult to recognise and people should not transfer bait fish from places that are already infested with Tilapia. Infested areas include Tinaroo Dam and some coastal catchments around Cairns. Anglers may not realise that it is Tilapia in their bucket and accidently introduce them to Tilapia-free catchments, such as the Mitchell River. Anglers need to be vigilant. It is the only way that we can control the spread of Tilapia to the Mitchell River and Gulf catchments. "
Recently Tilapia has spread through 3,000 kilometres of the Burdekin River over a 4 year period and will become the dominant species in this catchment. The only way to prevent more waterways becoming overwhelmed by Tilapia is for the public to actively report any sightings and enable an early and effective response wherever possible.
If you catch a fish that looks like Tilapia, take a photo of it, or put it in a plastic bag, contact the Pest Fish Hotline on 13 25 23 or 1800 017 116 (A/H) and pass the photo or fish on to someone who can confirm the identification and take action.
Tilapia Do’s and Don’ts:
Do:
- Find out what Tilapia look like from the information on this website or provided by the Department of Primary Industries and Fisheries (DPI&F))
- Kill Tilapia in a humane way, disposing of the fish well away from the water (bury on the bank or wrap in plastic and place in a bin)
- Contact DPI&F of any Tilapia sightings on 13 25 23
- Use bait native to the waterways you fish.
- Report anyone suspected of moving or dumping pest fish to the Fishwatch Hotline on 1800 107 116
Don’t:
- Do not use Tilapia as bait as they can release eggs or live young from their mouths even after death
- Do not move Tilapia between waterways
- Do not stock aquariums, dams or ponds with pest fish – use native fish from the same catchment instead
- Do not empty aquariums, dams or ponds into waterways either directly or indirectly via the sewer or stormwater drains.
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Gamba Grass - Fire Safety Issues
Sue Lamb, a Fire Control Officer from the Northern Territory with extensive experience of fighting Gamba grass fires, addressed a forum in Mareeba on 30 April 2008 on the extra hazards associated with fighting these fires. Gamba grass can have a fuel load of 30 tonnes per hectare (see picture below), which is about 8 times that of native grasses and undergrowth. This produces a very intense fire that is not only a danger to firefighters and vehicles but can also destroy the tree canopy. To see Sue's presentation click here.
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Electric ants alert!
A serious new pest in Queensland.
Smithfield and Kewarra Beach, in Cairns, are the main areas of electric ant infestation but it is important that all people in the region keep an eye out for this serious new pest and avoid practices that may cause a spread of the ants.
How You Can Help
Be on the lookout!
Electric Ants:
- Are tiny, about 1.5mm long
- Are a coppery colour all over
- Are usually slow moving
- Are social - they like to be with each other, often in heaps
- Do not have nests – electric ants establish colonies anywhere and have been found under stones, in garden waste, leaf mould, soil, trees, swimming pools and water courses, and may be in wall cavities, clothing, bedding or camping gear
- Can be found in wet or dry conditions
- Like water- they may ’jump’ into swimming pools and water bodies and form a ‘raft’.
If you see suspicious ants at anytime, call Department of Primary Industries & Fisheries (DPI&F) on 13 25 23 so a sample can be collected and identified.
Eradication activities being conducted in the Cairns region
The Queensland Government is undertaking a range of activities to combat electric ants, including:
- surveillance and treatment
- sample identification
- movement controls to stop the spread of electric ants
- engaging the community
- research and development of new treatment methods.
Sample identification
The Electric Ant Control Centre staff identify samples of ants collected during surveillance activities and by members of the community, to assist in defining the extent of this infestation. If you would like to be mailed a ‘Sample Kit’ to collect suspicious ants please call DPI&F on 13 25 23.
Community Talks
The Community Engagement Officer is available to present information about the ants to Community groups, these presentations provide an opportunity to view a sample of the ants, ask any questions, understand the ant problem and how they can help. Please call Daryl Mannell on 4044 1663 to book a presentation for your group.
The Electric Ant warning sheet can be viewed and printed by clicking on the image above.
Supplies of the warning sheet and posters are also available by contacting:
Daryl Mannell
Community Engagement Officer
Electric Ant Control Centre
Department of Primary Industries and Fisheries
21 Redden Street
PO Box 652, Cairns, Qld 4870
Telephone: 07 40573663
Mobile: 0423 822 211 Fax: 07 40573690
Email: daryl.mannell@deedi.qld.gov.au
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TRaCK - Information & Updates
http://www.track.gov.au
What is TRaCK?
TRaCK was established in 2007 as a research hub under the Commonwealth Environment Research Facilities Programme – the Australian Government’s commitment to world-class public good environmental research.
It brings together more than 70 of Australia’s leading researchers from social, cultural, environmental and economic disciplines to focus their expertise on the rivers and coasts in the both the wet and dry tropics stretching from Cape York across to Broome.
While not directly developing policy, TRaCK is providing independent, objective research to support decision makers and inform public debate in northern Australia. The TRaCK program will help ensure that any development proposals, especially for use of water resources, in Northern Australia will be sustainable.
What is the scope of TRaCK?
The Mitchell is one of several catchments in Northern Australia in which TRaCK researchers are focussing their attention. As noted by Hilary Kuhn (former chairperson Mitchell River Watershed Management Group Inc), “The Mitchell River has the largest annual flow of all tropical rivers in the country and is one of our most ecologically diverse aquatic systems. Yet there are few comprehensive biological and ecological studies of the catchment to date. Without the science, it is difficult for us to manage the catchment sustainably.”
To build our knowledge and capacity to manage the Mitchell, TRaCK researchers are working with all levels of government, regional NRM bodies, Indigenous communities, agriculture, fishing, tourism and mining industries, local land owners and other researchers to conduct field work and build on the existing knowledge about tropical rivers.
This work is being carried out in the following seven research themes:
Values and assets
Building an understanding of the range of values the Mitchell River system has to different people and how these can be better incorporated in decision making.
Classifying tropical rivers
Classifying river systems across northern Australia based on features such as flow patterns. This will help us understand what makes rivers such as the Mitchell similar or different to other rivers and underpin consistent policy development and regional planning.
Water, carbon, sediment and nutrients
Developing tools to predict how changes in land use and climate will affect the source, amounts and movement of water, carbon, sediment and nutrients in the Mitchell.
Food webs and biodiversity
Investigating the sources of energy (carbon) and nutrients that drive ecosystems and how they are transferred through food webs plus patterns of aquatic biodiversity and what determines these patterns.
Sustainable enterprises
Identifying enterprises for remote and regional communities based on sustainable and culturally appropriate use of riverine and coastal resources.
Evaluating scenarios
Bringing together the information and tools developed in the other themes to explore the social, cultural, environmental and economic implications of change in the Mitchell.
Communicating and integrating
Synthesising knowledge from the different themes and tailoring it to local communities, catchment and regional bodies, and government.
TRaCK will respond to these research themes through 21 specific projects. At least six of these projects are planning to do on-ground data collection (including meetings and workshops) in the Mitchell during 2008. Other projects will start their work in the Mitchell in following years. Yet other projects will include the Mitchell in a broader-scale, regional perspective. These projects will primarily be desktop exercises using existing information including remotely sensed data.
An information sheet has been produced to provide a brief description of projects likely to be on the ground collecting data in the Mitchell during 2008/9. It will be followed by more detailed fact sheets on each project.
A regular newsletter will also be published, click here for the latest issue.
Creek-side discussion at the initial TRaCK meeting at Karma Waters, July 2007
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