IN THIS SECTION - MEETINGS & CONFERENCES COMING SOON

NEWSLETTERS & ISSUES

Regenerative Agriculture Newsletter

Over the Fence #13 - Grazing Best Practice Newsletter

Tilapia found in the Walsh River Catchment

Electric Ants Alert!

Gamba Grass - Fire Hazard

Wild Rivers

Freshwater Sawfish Research

News from Australian Wildlife Conservancy

- From Dec. 2007 Wildlife Matters
Rare Chestnut Dunnart found at Brooklyn

- Wildlife Matters, Winter 2010 Issue

- Wildlife Matters, Summer 2010/11

- Wildlife Matters, Summer 2011/12

Alarming Decline in Small Native Mammal Populations in Northern Australia

In the past 10-20 years, there has been a catastrophic decline in the diversity and abundance of small mammals across northern Australia. From Cape York to the Kimberley, small mammals are disappearing. Urgent intervention is required to prevent a wave of mammal extinctions across Australia’s tropical savannas. Three years ago a team of AWC ecologists was carrying out a fauna inventory survey at a prospective property in the Northern Territory, to assess its conservation value for possible acquisition.

Over two weeks, traps were set at a range of remote locations, accessible only by helicopter. The survey sites were positioned in combinations of topography and vegetation that seemed guaranteed to deliver high densities of several mammal species. In over 1050 trap-nights, only two species of native small mammal were caught - a demoralising experience.

Sadly, this survey experience is not unique. Small to medium-sized mammals have vanished from vast areas of the north including some of Australia’s most famous national parks. This population collapse is undeniable with a growing body of unpublished survey reports and published research from across the north adding even more compelling evidence of a dramatic collapse in mammal populations.

Why are our northern mammals disappearing? Superficially, the tropical savannas of northern Australia appear intact. There has been very little clearing of vegetation. However, there are several factors which we know are having a profound influence on the ecological health and functioning of our northern savannas. These factors appear to be driving the decline of mammal populations. We do not yet fully understand how these factors are affecting mammal populations, or the relationship between these issues, but we are confident that the primary causes of the mammal decline are:

• Altered fire regimes (especially an increase in extensive and intense wildfires).
• Grazing by feral herbivores (especially feral cattle, buffalo, donkeys and horses).
• Predation by feral cats.

Weeds, disease and cane toads probably interact with, and compound the pressures from, altered fire and introduced species but, at this stage, there is no evidence to suggest they are the primary culprits.
AWC's Response - The Northern Mammal Recovery Project: This Project will involve creating large feral herbivore free areas at five AWC sanctuaries across northern Australia and measuring the response of native fauna at each of these sites.

Replication at several sites is essential to give confidence that the recovery witnessed at Mornington, the only protected area in northern Australia containing a large feral herbivore-free area, can be reproduced elsewhere. This project will therefore be unique in creating a network of large feral herbivore-free areas across the north.

Mornington Wildlife Sanctuary is the only protected area in northern Australia where a recovery in mammal populations has been recorded. AWC’s Northern Australia Project will seek to replicate the Mornington model by implementing a series of large-scale land management interventions at eight AWC properties located in each key region from the Kimberley to Cape York.

At each site, the Project combines an active land management response with an integrated research program addressing the key threats. The outcomes of thisgroundbreaking research will be invaluable in informing future land management decisions.

There is much more extensive discussion of the causes of this population collapse and the Northern Mammal Recovery Project in an article in the Winter 2010 issue of Wildlife Matters. There is an update on progress with the AWC response to this problem in the Summer 2011/12 issue of Wildlife Matters.

Alluvial Gully Erosion Rates and Processes in the Mitchell River Megafan & Role of Grazing Industry

This detailed report looks at the significant contribution of alluvial gullies to the total sediment load of the Mitchell River. These gullies are concentrated along main drainage channels and their scarp heights are highly correlated to the local relief between the floodplain and river. While river incision into the megafan over the last twelve thousand years has developed the relief potential for erosion, other factors such as floodplain hydrology, soil texture, chemistry and dispersibility, vegetation cover, land use, and land disturbance also influence the distribution and propagation of gullies, via changes in the driving and resisting forces. This report has also been published as a peer reviewed article in the journal Earth Surface Processes and Landforms.

Two dozen non-road influenced study sites (see below) were well distributed but locally randomly selected across the Mitchell megafan. Recent GPS measurements estimated the average annual rate of scarp retreat to be 0.23 m per year across 50,040m (50 kilometres) of common gully front. Maximum rates exceeded 14m per year, with scarp heights ranging between 0.3 and 8 m. Alarmingly the alluvial plains of the Mitchell River megafan are so extensive that, without intervention to manage erosion and limit it's expansion, the erosion fronts will continue to progress for 100s of years, and even thousands in some places, before they would be naturally limited by some change in soil structure or landscape.

Historic air photo analysis and GPS surveys of changes in gully area over time (1949 to 2009) demonstrated rapid growth of gullies over that period, with gullies increasing in size by 2 to 10 times their initial area since 1949. Extrapolation of gully area growth trends backward in time suggests that the current phase of gullying initiated between 1870 and 1950. This is a time period of rapid increases in cattle grazing across the lower Mitchell catchment. These results of post-European settlement gully initiation suggest the contribution of land use intensification (cattle grazing and fire regime changes) to either gully initiation or acceleration. While some degree and form of gullying existed pre-European settlement and cattle introduction (Leichhardt 1847; Gilbert 1845), it appears that this gullying was limited in extent and rate as compared to the current distribution and style of gullying.

A shorter paper on this topic was presented at the 19th World Congress of Soil Science in Catchments in August 2010. This paper focused on the dramatic land-use changes in northern Australian from traditional Aboriginal management to widespread cattle grazing post-European settlement. This paper proposes that quantifying the soil erosion impacts of these changes is essential to the future sustainable management of the soils in these catchments.

Another research paper is about the use of remote sensing to quantify sediment budgets, particularly in the fluvial megafan section of the Mitchell River catchment, which is the largest in Australia (31 000 km2) and is dominated by unconsolidated alluvial silts and clays.

AN AMBIENT WATER QUALITY SURVEY OF THE UPPER WALSH RIVER SYSTEM, NORTH QUEENSLAND

This report and it's site profiles, prepared by the Australian Centre for Tropical Freshwater Research (ACTFR) at James Cook University, details the findings of an ambient water quality and ecological condition assessment project carried out in the upper Walsh River and selected tributaries (including Two-Mile Creek in the upper Mitchell Catchment), late in the 2006 dry season. The study found very poor quality water with elevated nutrient levels being discharged from the intensively developed sub-catchments (particularly Cattle Creek) within the Mareeba-Dimbulah Irrigation Area and into Two Mile Creek, a tributary of the upper Mitchell catchment that receives discharge from the Mareeba sewage treatment plant, which is also infested with aquatic weeds. The nutrient concentrations that have been reported in these creeks are two to ten times higher than any level that could be considered acceptable, and historical data indicate that this has been the case for more than a decade. In fact, some of the ammonia concentrations are actually high enough to be acutely toxic to aquatic animals and could cause fish kills under unfavourable (high) pH conditions.

There are ongoing community concerns about the water quality impacts of the numerous abandoned mines scattered throughout the Walsh River catchment, most of which were not properly rehabilitated. Some of these have already been shown to be discharging metals and other contaminants into waterways, so the existence of some highly contaminated sites is to be expected. Some significant metal concentrations were recorded in the vicinity of mine sites, but these were confined to quite small waterbodies with considerably lower ecological value than the waters in the irrigation area. Moreover, only one such site, Poison Water on Oaky Creek, reported metal concentrations (for zinc, aluminium and copper) high enough to be certain that the water was highly toxic to aquatic life.

The concentrations of copper in Cattle Creek (and also the Walsh River) were high enough to be ecologically significant with the highest copper concentrations being recorded in the Walsh River between the MDIA supplementation point and Cattle Creek. This suggests that the copper may be coming from the irrigation supply and that the inflows from Cattle Creek were actually diluting the copper in the river (and that is the only parameter for which that occurred). All sites that were receiving irrigation water reported concentrations of filterable copper that exceeded ANZECC (2000) guidelines for the protection of aquatic ecosystems, and the site with the highest concentration had significantly lower macroinvertebrate diversity than any other site on the river. These copper concentrations are orders of magnitude too low to affect human water uses, but they are more than high enough to potentially impact on the ecosystem, making the copper in the irrigation supply the most ecologically significant and widespread occurrence of metal contamination that was encountered during this study.

SPECIAL FEATURES, PROJECTS, REPORTS ON FORUMS AND MEETINGS

Small Native Mammal Population Decline & Erosion Processes in Mitchell River Catchment - Workshop at Almaden, 7-8 June 2011

This project was funded by a Community Action Grant through the Australian Government’s Caring for Our Country program. The first workshop in Almaden was attended by 9 graziers who, between them, manage 365,000 hectares of grazing property. The primary reason for the project and workshops was to inform graziers of the latest research on biodiversity, especially the decline of small native mammal populations across Northern Australia, and the results of the recent TRaCK (Tropical Rivers and Coastal Knowledge) program and the current Griffith University research into erosion and sediment budgets in the Mitchell River catchment. Click here for a report on the workshop and below for presentations. More detailed papers on these issues can be found to the left. A second workshop will be held in the week beginning October 24th 2011 and anyone interested should contact Brynn Mathews at the MRWMG office.

- Delbessie Leasehold Land Assessment Process

- Small Native Mammal Population Decline

- $avanna Plan for Improved Cattle Productivity

- Soil Health- Measuring & Understanding

- GPS/Remote Sensing & Property Mapping

- Biodiversity & Ecosystem Services

Alluvial Gully Erosion
- Introduction
- Processes
- Rates & timing
- Sediment Budget
- Rehabilitation

Northern Australia Water Futures Assessment - Newsletter #1, January 2011

The Northern Australia Land and Water Taskforce (see below) has evolved into a new body, the Northern Australia Water Futures Assessment (NAWFA), with the mission of informing the development and protection of northern Australia’s water resources. NAWFA has been using TRaCK to carry out some of its research and has just released its first newsletter. This newsletter gives an overview of NAWFA and its four programs dealing with:
1. Water Resources;
2. Ecological Assets;
3. Cultural and Social beliefs, values and practices; and
4. a Knowledge Base to inform future development and protection of these water resources.
The newsletter also includes links to a number of reports including one titled "Moving water long distances: Grand schemes or pipe dreams?"

Northern Australia Land and Water Taskforce

Final Report Released

The Northern Australia Land and Water Taskforce Final Report was publicly released on 8 February 2010 and can be downloaded at:
http://www.nalwt.gov.au/reports.aspx

The MRWMG and Northern Gulf Resource Management Group submitted a detailed statement on issues and concerns for water management in the Mitchell River catchment. This was included as Chapter 26 in the Science Review (2009).

The final report examines the longer term, strategic potential for further land and water development in northern Australia, with particular emphasis on the identification of the capacity of the north to play a role in future agricultural development. The impetus for this study was changing water resource security in the south and the likely collapse of the whole Murray -Darling catchment and the irrigated agriculture that depends on it.

In particular the report identifies the potential for sustainable development through:

1. Expanding agricultural production by developing small scale, widely distributed appropriately located production units - mosaic agriculture.
2. Intensifying production in the billion dollar beef industry through the irrigated production of fodder crops across the north. An expanded beef industry also provides the potential for sustainable wealth creation in indigenous communities.
3. Protecting the north's natural ecosystems to ensure the long term sustainability of the multibillion dollar tourism industry.
4. The recognition of conservation and natural resource management across northern Australia as a valuable contributor to the region's economy.
5. Acting on the opportunities for indigenous people to build on their comparative advantage in providing customary and commercial services on the vast indigenous estate in northern Australia.

The proposed intensification of pastoralism would enable large areas of rangelands to be taken out of beef production and managed for cultural and conservation activities, including carbon storage.

Any grand dreams of more Ord River schemes with massive water storages and irrigated farmlands were severely limited by factors such as:
- despite high rainfall, the north is seasonally water limited; and
- the ability to capture and store water is constrained by climate (high annual evaporation rates) and topography (it's basically flat); and
- surface and groundwater systems and the biodiversity of the region are highly connected with the complex interactions between them being poorly understood.

Kowanyama Weed Forum -
25-26 June 2009:

This workshop brought together the Kowanyama Rangers, and other staff responsible for weed management on land under the community's control, with other stakeholders in the region. Information on current best management practices for weeds of concern in the area, both already present and on their way, was presented by experts from government agencies. A field trip highlighted existing weed problems, especially in wetland and lagoon areas. Information was also presented on other projects being carried out in the area.

Presentations:
Cape York Weeds & Ferals Program

Hymenachne

Grasses, Chinee Apple, Rubber Vine,

Bellyache Bush

Parkinsonia

Pond Apple

TRaCK Food Webs Project Update

Pest Management Planning in Indigenous Communities - Biosecurity Qld

Biofuels - Jatropha curcas

Presentations from Mt Molloy Meeting 13 March 2008

Peter Holden (DPI&F) & John Clarkson (QPWS)

Palmer River Forum

16 May 2008, Mareeba
Report with Presentations

Tilapia found in Walsh River Catchment at Eureka Creek & Removed

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

• 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.

Electric ants alert!

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

Palmer River Forum - May 16 2008, Mareeba

This forum was made possible by funding from the Cape York Peninsula Landcare Program and was well attended by almost 60 miners, graziers, Traditional Owners and other interested residents of the Mitchell River catchment. Speakers told the audience about a range of topics including best practice in road construction and maintenance for miners, stream management and diversion for mining, sediment budgets for the Palmer River, the Traditional Owner perspective on Native Title and Indigenous Land Use Agreements (ILUAs), an overview of the Tropical Rivers and Coastal Knowledge (TRaCK) project, controlling weed spread on vehicles and machinery, EPA management of small mining and the impact of historic mine sites in the Nevada City area of California (an area with a very similar mining history to Irvinebank/Herberton).

The forum then identified issues of concern and split into three groups to discuss them. The outputs of this discussion set a number of key issues to be addressed by a future working party that will develop a set of best practice guidelines for alluvial mining.

Wild Rivers

In October 2005 the Queensland Government passed the Wild Rivers Act. Since then 9 rivers have been declared as Wild Rivers - Staaten, Morning Inlet, Gregory, Settlement, Hinchinbrook Island and Fraser Island on 28 February 2007 and the Archer, Stewart and Lockhart Rivers on 3 April 2009. The Wenlock River has been proposed for declaration and public consultation closed on 29 May 2009. Natural Resources Mines and Water have released a revised Wild Rivers Draft Code, this document describes in detail what and how resource use activities will be assessed in the area of a declared Wild River. The Government carried out extensive public consulatation and sought submissions on both the nominations and the Codes of Practice.
                                      
When the first 6 rivers were declared in February 2007, there was also a moratorium declared on 13 rivers of the Cape York Peninsula. The moratorium applies to new permits for taking or interfering with water in streams, sub-artesian aquifers and overland flow and an information sheet can be viewed at:
http://www.derm.qld.gov.au/wildrivers/cape_york.html

DERM has also prepared an information sheet especially to address the concerns of the indigenous community about what will and won't be allowed in a declared Wild Rivgewrs area. For further information on the Act, Policy declarations and more, go to the Department of Environment and Resource Management website

Freshwater Sawfish Research

A Masters thesis study was undertaken on this remarkable creature Pristis microdon also known as Freshwater sawfish, Leichardt's sawfish or the Smalltooth sawfish. The Mitchell River appears to hold reasonable numbers of these animals. The dwarf and green sawfish are found more towards the mouth of the river in the estuarine section. The research looked at the biology and ecology of sawfishes within QLD. Part of the study involved a tag/release program operating in the Mitchell River. Research so far shows that the freshwater sawfish has a marine component to its life cycle. Mature animals come into the mouths of the rivers to drop their pups during the wet season and then juvenile to sub adult sawfish then venture upstream with the receding floodwaters.

The Marine Education Society of Australasia (MESA) chose the plight of the declining Freshwater sawfish as the theme for Seaweek 2008. As part of the weeks activities MESA released an on-line story titled "The Adventures of Sonya the Freshwater Sawfish". Click here if you want to read this story.

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.