Security against invasive species such as weeds and feral animals it paramount to ensure environmental and agricultural assets are protected. The Ord Catchment is particularly vulnerable due to its proximity to the WA/NT border and its interstate and international entry points. As biosecurity cuts across all primary and secondary industries as well as the community strong leadership is required from a multitude of stakeholders including State agencies through the Department of Agriculture and Food Western Australia, the Shires of Halls Creek and Wyndham East Kimberley, industry groups such as the Regional Biosecurity Group and tourism organisations.
To minimise the impact of feral species on native flora, fauna and pastoral production within the catchment.
To increase the understanding of pest and feral species, their impacts and control methods.
Feral animals are species that have been introduced to an area and whose populations have become naturalised. For example, cats, dogs, donkeys, cane toads and wild horses. Some native species can become pest species if their populations reach plague proportions, for example the native brown rat (Rattus villosissimus) which has had an impact on local irrigated crops in the past and the agile wallaby (Macropus agilis) which can over populate an area and impact on destocked paddocks.
The Department of Agriculture and Food, Western Australia and The Department of Parks and Wildlife provide advice to property owners who are controlling pest and feral animals to ensure that the impact of the control measures on the native species is minimal.
The Recognised Biosecurity Group (Kimberley Rangelands Biosecurity Association) plays a key role in pest and feral animal control on pastoral land. It has a number of feral animal control programs, including the highly successful Judas program that has significantly reduced donkey numbers since its inception by using radio telemetry systems to track the animals.
Without adequate control of donkeys it is not possible to achieve acceptable stocking rates and ensure that pastoral activities do not degrade rangelands or adversely impact on rivers and waterways (Water and Rivers Commission, 1997).
There is currently a control program under way throughout the Kimberley called the Judas program. It involves using radio collars as a means of monitoring the movements of the herd and controlling numbers. As a result of this program the donkey populations in the East Kimberley are now well under control. However there is constant re-introduction of donkeys from the Northern Territory where numbers remain high. The Victoria River District Conservation Association currently has had in the past a number of donkey control programs situated on the border area that have helped to reduce numbers moving into Western Australia.
There are feral pig populations located at various locations within the catchment, usually focused around water bodies such as the Ord River, however, these populations are currently only small. Pigs have the ability to cause damage to riverbanks, create erosion in these areas, encourage weed growth and transmit disease. Pigs also have the potential to cause damage in horticulture crops, as well as in cane, maize, and cucurbit crops. The Department of Agriculture and Food Western Australia provides advice on their control and the Recognised Biosecurity Group has a small Kimberley wide control program.
Feral cats are a problem as they prey on small native animals. There are currently no by-laws for the control of cats in the Shire of Halls Creek but they do have an active trapping program for wild cats around the townsite. The Shire of Wyndham East Kimberley has a Domestic Animal Management Plan and enforces both the Dog Act 1976 and Cat Act 2011.
Wild dogs, (which under the Biosecurity and Agriculture Management Act 2007 definition include dingoes) can cause problems for property owners who have young stock. The Department of Agriculture and Food, Western Australia provides advice on their control and the RBG provides a twice a year aerial baiting service to pastoralists across the Kimberley. In addition, pastoralists often carry out their own baiting programs throughout the dry season. One issue pastoralists can encounter is neighbouring properties not baiting or not baiting regularly, potentially creating a refuge for wild dogs to roam from.
To help reduce the problem of domestic dogs becoming wild and adding to the wild dog population, the Halls Creek and Wyndham East Kimberley Shires offer reduced dog registration fees for sterilised dogs.
The Department of Agriculture and Food Western Australia and the Recognised Biosecurity Group undertake opportunistic control in conjunction with the donkey telemetry program.
However, no overarching management plan for wild horses currently exists but the Department of Agriculture and Food Western Australia and the Recognised Biosecurity Group see the increased populations of horses within the catchment as a potential threat to pastoral management. It is expected that regular horse control as part of land management practices will need to be implemented in the near future as wild horse numbers increase.
Camels are controlled opportunistically by land managers and the Recognised Biosecurity Group during donkey control runs. Their numbers within the catchment have always been relatively low compared to desert areas and also subject to seasonal variations.
European Honey Bees
European Honey Bees are regularly brought into the Ord River Irrigation Area to aid in the pollination of horticultural crops that are generally not pollinated by native bees. Native bees prefer small flowers, flowers in dense bunches and flowers on trees (Heard and Allan 1998).
No European Honey Bees are allowed into WA from other states and all bees that are brought into the Ord River Irrigation Area are sourced from specific apiaries to minimize the risk of imported exotic apiarian diseases.
Some concern exists within the community that the European Honey Bee may be having a detrimental impact on the native bee population by swarming into the bush and competing with native bees for food.
Cane toads (Rhinella marina formally Bufo marinus) were deliberately introduced into Australia in 1935 in an attempt to control sugar cane pests in Queensland. They have since spread, throughout much of Queensland, northern New South Wales and the Northern Territory. The first toads crossed into Western Australia in February 2009. Their first known entry point was the Victoria Highway 50 kilometres west of Kununurra. The movement of the invading cane toad front has increased in pace over time, with the front now moving at an average rate of approximately 50 kilometres a year.
The cane toad is listed by the World Conservation Union as one of the world’s worst 100 invasive alien species. They can impact on native species by way of:
poisoning through ingestion;
competition for habitat and food.
The community response to the threat posed by cane toads in WA was unprecedented, with community groups including the Kimberley Toad Busters and the Stop the Toad Foundation working alongside of the Department of Parks and Wildlife to prevent the entry of toads into the State.
Despite all efforts toads continue to move south and west across the Kimberley. In 2015 they were close to Halls Creek and may have already entered the upper reaches of the Fitzroy River catchment. It is clear that their movement cannot be stopped using any of the methods currently available.
Quarantine WA is to be notified of any importation of insects into WA. There is a list of insects that can be imported and postal deliveries are subject to inspection.
When growers bring in stocks of beneficial insects for release it is called augmentation. Basically this refers to releases of large numbers of natural enemies with the aim of achieving an immediate impact on the pest populations.
The beneficial insects used are species that occur naturally in the area, such as the parasite Trichogramma which parasitises eggs of Helicoverpa, and predatory lacewings, which feed on aphids and other pests. Normally as pest species increase these parasites and predators would also increase. The releases merely speed up this process (Brian Thistleton pers comm).
Since these insects are already found in the area their release is not likely to have a significant impact on native insect populations (Brian Thistleton, pers comm).
Feral cat status in the area.
The most effective way to prevent the further introduction of feral animals.
The impact of European Honey Bees on Native Bee species in the area.
Whether it is possible to control horses and pigs using ‘Judas’ collar techniques?
Effective control of cane toads at a landscape level.
Reduce the impact of pest and feral animals by:
1. Monitoring pest, feral and potential feral species that are in the area by:
Encouraging community members to document what they see while they are in the bush and report to either the Department of Agriculture and Food Western Australia or the Department of Parks and Wildlife.
Developing easy to read identification material on feral species to ensure ease of correct identification.
Encouraging the Department of Agriculture and Food Western Australia and the Department of Parks and Wildlife to increase their own surveillance activities.
2. Educating animal owners and making them aware of the issues by:
Encouraging the Shire to advocate for the sterilisation of pets through continued reductions in pet licensing fees.
Working with local vets to provide education material on reducing the impact of domestic animals on the feral populations.
3. Researching potential feral and pest species; to include how they move and ways to effectively monitor and control these species.
4. Gaining information on feral and pest species research results undertaken by other organisations.
Control or eradicate feral animals where appropriate and feasible.
Responsibility for dealing with pest and feral animals lies with a number of different organisations. Local residents (who are pet owners) have a significant responsibility to ensure that they control their animals in a manner which reduces the pet’s impact on native species. Shire councils have a responsibility to ensure that suitable By Laws are developed, maintained and enforced to control feral animals.
The Department of Agriculture and Food Western Australia has responsibility for providing identification material and managing feral animals that may have an impact on the agricultural industry. The Department of Parks and Wildlife has a role to play in controlling feral animal species such as cats in conservation estates. The Recognised Biosecurity Group has a responsibility to control declared animals on pastoral land.
Community groups need to be involved to help increase the amount of local information available, to improve the management of pest and feral species.
1. Gardiner, H.G. (2000) Ord Land and Water Management Plan 2000. National Heritage Trust: AGWEST.
2. Dr. Heard, T. & Dr. Dollin, A (1998) Crop Pollination with Australian Stingless Bees: Australian Native Bee Research Centre, Richmond, NSW.
3. Schwarz, M.P. & Hurst, P.S. (1997) Effects of Introduced Honey Bees on Australia’s Native Bee Fauna: The Victorian Naturalist, Vol. 114(1).
4. Manning, R. (1997) The Honey Bee Debate: a Critique of Scientific Studies of Honey Bees Apis melliferna and Their Alleged Impact on Australian Wildlife: The Victorian Naturalist, Vol. 114(1).
To minimise the impacts of invasive weed species on the catchment.
To ensure the development of the Regional Weed Strategy in order to reduce the impact of current weed species on the area.
To improve community and industry awareness of invasive weed species, their impacts, prevention and control methods.
A weed can be described as any troublesome or noxious plant, especially one that grows profusely or any plant growing where it is not wanted (Hussey, 1997). Weeds can be divided into four categorie; Weeds of National Significance, declared weeds, environmental weeds and weeds that impinge on agricultural production.
Weeds of National Significance have been determined by Australian governments based on an assessment of their invasiveness, potential for spread, environmental, social and economic impacts and their ability to be successfully managed. Declared weeds are those that have to be controlled in specific ways by law or statute. The level of control can range from eradication to containment. Environmental weeds are plants, which are introduced to an area and have the potential to cause environmental problems if conditions are right. Weeds that impinge on agricultural production are weeds that usually grow as a result of agricultural practices such as irrigation or regular land disturbance. Often they can only exist as a weed in conditions that have been created and maintained by agriculture. Local examples are; barnyard grass Echinochloa spp), Rubber Bush (Calotropis procera) and khaki weed (Alternanthera pungens).
In Western Australia the Department of Agriculture and Food Western Australia plays the lead role in protecting the State’s agricultural industry from pest plants, whilst the Department of Parks and Wildlife takes on a similar roll on Crown land and Reserves.
The Recognised Biosecurity Group is a regional organisation with a committee and members drawn from those who pay the Declared Pest Rate (Pastoralists). Their role is the prioritisation and control of declared plants and animals. Currently they are funding the control of rubber vine (Cryptostegia grandiflora), mesquite (Prosopis spp) and prickly acacia (Vachellia nilotica) within the region.
Shires can declare pest plants in their respective Local Government Areas however, once declared they have a responsibility to control the declared weeds.
Currently the following Declared Weeds are known to occur in the East Kimberley:
|Bellyache Bush||(Jatropha gossypiifolia*)|
|Candle Bush||(Senna alata)|
|Chinee Apple||(Ziziphus mauritiana)|
|Gamba Grass||(Andropogon gayanus)|
|Giant Sensitive Plant||(Mimosa pigra)*|
|Mesquite||(all Prosopis species and hybrids*)|
|Noogoora Burr||(Xanthium strumarium)|
|Olive Hymenachne||Hymenachne amplexicaulis|
|Prickly Acacia||(Vachellia nilotica*)|
|Rubber Bush||(Calotropis procera)|
|Rubber Vine||(Cryptostegia madagascariensis and Cryptostegia grandiflora)|
Also Weeds of National Significance*
Weeds that are listed as environmental weeds for the region include but are not limited to:
|Cobblers Peg||(Bidens pilosa)|
|Goat’s Head Burr||(Acanthospermum hispidum)|
|Hairy Merremia||(Merremia aegyptia)|
|Khaki Weed||(Alternanthera pungens)|
|Mimosa Bush||(Vachellia farnesiana)|
|Mint Weed||(Hyptis suaveolens)|
|Mission Grass||(Cenchrus pedicellatus)|
|Para Grass||(Urochloa mutica)|
|Sorghum almum||(Sorghum almum)|
|Stinking Passion Vine||(Passiflora foetida)|
|Tick Weed||(Cleome viscose|
It should be noted that many of the weeds listed above are also significant agricultural weeds. These weeds can inhibit good native pasture growth and interfere with irrigated agriculture production.
No invasive aquatic weed species are believed to be present in the East Kimberley. A small area of Salvinia (Salvinia molesta) was found in Lily Creek off Lake Kununurra in May 2000. This was finally declared eradicated in October of 2009. Ord Land and Water played a lead role in the plant’s eradication over that period of time.
Many aquatic plants grow profusely in the area. However, they are all native plants to the area and following the damming of the river have proliferated. At times these plants can cause problems with recreational use of the waterway.
Chemical use in irrigation channels
In the Ord River Irrigation Area, native weeds in the delivery channels need to be controlled as they inhibit the movement of water down the channel. The current practice used by the water service provider (Ord Irrigation Cooperative Ltd.) is to inject Magnacide H® (Acrolien active constituent) into the water as required. The chemical kills plants and some animals such as fish living in the water.
The Department of Agriculture and Food Western Australia has a role in keeping the State weed, pest and disease free, with its core business being to protect agriculture. All cars entering Kununurra from the Northern Territory (NT) have to pass through a quarantine station at the WA/NT Border. Vehicles carrying horses or cattle must be washed down at the quarantine yards or similar facility. Some cattle trucks moving stock to the Wyndham Port have conditional exemption to washing down providing they return directly to the Northern Territory. This quarantine role is important, as there are a number of invasive weed species found in the NT that are not found in WA.
The Federal Department of Agriculture and Water Resources carries out regular weed and other pest surveys in search of any new species of foreign plants.
Projects Under Way
Mesquite control program on Nicholson Station.
Prickly acacia control program on Nulla-Nulla community.
Rubber vine control program on the Ord and Bow rivers and Oombulgurri Community.
Mimosa pigra control program on Lake Argyle, Ivanhoe Station and Parry Creek Reserve.
Belly ache bush control within the ORIA.
Parkinsonia and sicklepod senna control in Goomig Farm Area buffer.
Lantana control north of Kununurra.
Lack of understanding of biological control of weeds.
Knowing which are the principal weeds that may cause problems in the future.
Properly identified weed pathways into the region.
Herbicide resistance issues.
Prevent the introduction and spread of new weed species to the area by:
1. Maintaining the border checkpoint.
2. Development of a Regional Weed Strategy.
3. Continuing to develop an education and awareness program about current weed species and future potential weeds by using:
having a weeds section in regional web sites
regular newspaper articles
4. Developing an easy to read updateable booklet on weeds in the region.
5. Encouraging farmers, anglers, bushwalkers, etc to report sightings of weed species.
6. Providing easy to access plant identification material to the general public.
Control or eradicate weed species where appropriate and feasible.Strategy 3
Encourage the completion of a Kimberley Weed Management Strategy through The Department of Agriculture and Food Western Australia and develop guidelines for the management of weeds in the area.
The Recognised Biosecurity Group has responsibility for controlling declared weed species on pastoral land. The Department of Parks and Wildlife has responsibility to control weeds on Crown land, Reserves and National Parks. The Department of Agriculture and Food Western Australia has the responsibility of looking for weed infestations and in some cases take a role in their control or eradication. Landholders have a responsibility to ensure that they do not introduce weed species to their gardens/areas of land that have the potential to become problem species. Shires have a responsibility for managing weed species in Local Government Areas (they also have the power to declare pest plants as described earlier).References
1. Gardiner, H.G. (2000) Ord Land and Water Management Plan 2000. National Heritage Trust: AGWEST.
2. Hussey, B.M.J. Keighery, G.J., Cousens, R.D. Dodd, J. Lloyd, S.G. (1997) Western Weeds – A guide to the weeds of Western Australia: The Plant Protection Society of Western Australia.
3. Western Australia Department of Agriculture (1999) Kimberley Pastoral Memo, August 1999.
4. Department of Agriculture and Food (2016) Weeds: www.agric.wa.gov.au.
5. Australian Government Department of Agriculture. (2016) Pests, Diseases and Weeds: http://www.agriculture.gov.au/ website.