Download Joint Submission DELWP, DEDJTR and Parks Victoria Attachment

Emerging Invasive Animal Issues – Further Information
SUBMISSION 210
ATTACHMENT 16
RECEIVED 14/09/2016
Feral pigs
Feral or wild pigs (Sus scrofa) are declared as established pest animals under the Catchment and
Land Protection Act 1994. Feral pigs are considered an environmental pest due to their selective
feeding, trampling and rooting for underground parts of plants and invertebrates, as well as
predation on, competition with, or disturbance of a range of native animal species. Feral pig activity
also has a dramatic effect on watercourses and swamps. By wallowing and rooting around the
waterline, they destroy the riparian vegetation which provides food and nesting sites for native
wildlife and helps to prevent soil erosion. Water quality is also affected and their diggings may
spread undesirable plant and animal species, and plant diseases in these areas.
Feral pigs cause significant damage in agricultural areas. They prey on newborn lambs, compete with
livestock for pasture and can damage infrastructure such as fencing and water facilities. Feral pigs
can reduce yields in grain, sugarcane, fruit and vegetable crops, through uprooting and consuming or
trampling of plants, and their wallowing and defecation foul dams and waterholes.
Feral pigs are known to be vectors for a number of serious endemic and exotic diseases that have
the potential to devastate commercial pig operations, as well as transmit to other animals and
humans. Examples include foot and mouth disease virus, leptospirosis, brucellosis, melloidosis and
Japanese encephalitis. A code of practice and relevant standard operating procedures for public land
managers undertaking feral pig control in Victoria. With appropriate permission, approval and
licences, feral pigs can be hunted throughout Victoria on private and public land, although ground
shooting alone is not considered best management practice. Trapping of pigs is considered an
effective integrated control method when implemented in a coordinated manner at a landscape
scale.
Feral Goats
The feral or wild populations of goats (Capra hircus) are declared established pest animals under the
CaLP Act. There is little information available regarding the distribution and density of feral goats in
Victoria. However, anecdotal information suggests that the largest goat populations occur in areas
where very large tracts of forested or semi-arid areas offer some protection from control and
people.
Feral goats cause considerable environmental impacts in Victoria. Feral goats cause land degradation
through soil damage, over grazing and strip browsing. The soil's crust and its protective cover of
vegetation are disturbed through trampling by the goat's hooves. As a selective browser, feral goats
can impact on specific plant communities over a relatively short period. Feral goat populations affect
long lived plants by eating established plants and preventing the recruitment and growth of
seedlings.
Feral goats are a major environmental and agricultural pest throughout Australia. Competition and
land degradation by feral goats is listed as a key threatening process under the EPBC Act.
Economic losses as a result of the impact of feral goats can be split into four areas: costs to primary
production; costs associated with exotic diseases; costs of land degradation caused by goats; and
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costs to the public to manage goats. The monetary value of economic losses in Victoria is unknown,
however the cost to Australia as a whole is estimated at up to $25 million per annum.
While feral goats are found mostly on public land in Victoria, they are also found on private
property. Feral goats and domestic livestock have overlapping diets and habitats which can cause
competition with domestic livestock for food, water and shelter. Feral goats are capable of outcompeting and outlasting both sheep and kangaroos in time of drought.
Feral goats are known to be susceptible to several diseases of livestock including Ovine Johne's
Disease, foot-and-mouth, rinderpest, rabies and blue tongue. Unchecked wild herds could
potentially play a major role in the spread of disease and act as a reservoir for these and other
livestock diseases if diseases are introduced into Australia. Agriculture Victoria has developed a code
of practice and relevant standard operating procedures (Attachment 22) for public land managers
undertaking feral goat control in Victoria. Elsewhere in Australia, the commercial harvesting of feral
goats can be a profitable enterprise for rural economies.
Feral Cats
There is increasing recognition of the impact of feral cats on threatened wildlife and biodiversity in
Victoria. Feral cats are the same species as domestic cats, however they live and reproduce in the
wild. Feral cats are animals that live completely independent of humans with respect to food, shelter
and veterinary care, as distinct to domestic cats that are important companion animals for many in
the community.
The Department of Environment, Land, Water and Planning is currently reviewing Victoria’s
jurisdictional arrangements that may support the management and control of feral cats in Victoria
for the protection of threatened wildlife and key biodiversity values.
Invasive Marine Species
The control of invasive species on Crown land needs to consider the inclusion of the marine
environment. The introduction of non-indigenous marine species can act as vectors for new
diseases, alter ecosystem processes and reduce biodiversity, have significant economic impacts and
disrupt human activities. Introduced marine pests are non-indigenous marine plants or animals that
are often introduced by human activities such as shipping.
Increasing trade, transport and tourism, have greatly expanded the numbers of marine organisms
that are moved around the world and the locations that they have spread to. Roughly 250 marine
species are known to have been introduced to Australia's marine waters with more than 100 species
known to have been introduced to Port Phillip Bay alone. Examples include Japanese seaweed or
Wakame (Undaria pinnatifida) and the Northern Pacific seastar (Asterias amurensis) both of which
can have significantly detrimental impacts on Victoria’s marine environment.
Once established, the management of marine invasive species is often problematic due to the
inherent difficulties in sampling, delimiting populations due to the microscopic larval stages of many
species as well as the physical nature of the marine environment. Control is often undertaken
through the physical removal of species. For example, management of U. pinnatifida in the heavily
infested port of Apollo Bay has previously involved the use of recreational volunteers to physically
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remove the species from the structures within the harbour. In 2010, divers removed 4.5 tonnes of
the invasive marine species.
Invertebrates
DEDJTR manages the risks and incursions of both vertebrate and invertebrate invasive species. For
example, globalisation of trade and commerce has accelerated the spread of a subset of seven
species of ants – the ‘tramp’ ants – widely beyond their areas of origin. Tramp ants share genetic,
behavioural, and ecological attributes that affect their probability of entry, establishment and
spread, ecological dominance, and high levels of impact. Many of these tramp ants have established
and spread in Australia and its territories or have the potential to do so.
The first detection in Australia of red imported fire ant occurred in Brisbane in 2001 and triggered a
national cost-shared eradication program led by the Queensland Department of Primary Industries.
The red imported fire ant has the capacity to form 'super colonies' with multiple queens that can
spread rapidly and develop extensive colonies. The species can significantly affect ecosystem
processes through reducing plant populations and competing with native herbivores and insects for
food. Fire ant stings are painful and the alkaloid venom causes pustules and, in some people, severe
allergic reactions. The reduction in the biodiversity of Australian native fauna and flora due to the
red imported fire ant is listed as a key threatening process under the EPBC Act and a threat
abatement plan has been developed. Victoria is a member of the tramp ant National Working Group.
By mid-2014, the Commonwealth and state/territory governments had spent $300 million
attempting to eradicate red imported fire ants. Although expensive, this is far less than the costs of
failing. Modelling by the Queensland Government indicates that in southeast Queensland alone fire
ants would impose costs of about $43 billion over 30 years. In the US the ant costs nearly $7 billion a
year in damage and control.
Victoria has a low risk of infestation of fire ants. Fire ants are currently not known to occur here,
however there were two detections in Victoria during 2001. Fire ants are a declared exotic pest
under the Plant Biosecurity Act 2010 and a comprehensive set of regulations are in place to control
the movement of high risk materials from Queensland, including nursery plants, potting mixtures,
mulches, soil and equipment. If discovered, a well-planned eradication and containment program
will immediately be put in place.
Reptiles and Amphibians
Invasive amphibians and reptiles generally have a high reproductive rate, which facilitates rapid
population growth and recovery from stochastic events. They have generalized diets that effectively
utilise locally abundant resources. Typically, successful invaders are small or secretive, which allows
undetected movement in transportation networks. These cryptic behaviours also allow the
development of incipient populations that are difficult to detect until the animal is well established.
Examples of invasive reptile and amphibian species are provided below:
The deliberate introduction of the cane toad (Rhinella marinus) to Australia in 1935 was an example
of a poorly planned biological control program. Since then, cane toads have expanded through much
of Australia’s northern landscape and are moving westward at approximately 40-60km per year.
Adult cane toads produce toxin from glands over their upper surface, but especially from bulging
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glands on their shoulders — these exude venom when the toad is provoked. While some birds and
native predators have learned to avoid the poison glands of adult toads, other predators are more
vulnerable and die rapidly after ingesting toads.
The Asian black-spined toad (Duttaphrynus melanostictus) is not native to Australia and if given the
opportunity could establish in Victoria. It is regularly detected and intercepted at the border. If it
became established it could compete with native frogs and toads for food and suitable habitat and
has the potential to carry exotic parasites and diseases. The toads’ skin secretions contain several
bioactive compounds with lethal, hypotensive, hypertensive, neurotoxic, cardiotoxic, haemolytic and
sleep inducing factors, potentially causing severe impacts for native species which may prey on the
toad.
Asian black-spined toads are classified as a prohibited pest animal under the CaLP Act. The
importation, keeping, breeding and trading of this species, without appropriate permits, is illegal and
penalties apply. An increasing number are being intercepted at Australian airports and sea ports
from flights and ships arriving from Asia, where the toad is widespread. They are usually found in
shipping containers, machinery and personal effects such as bags and shoes. Agriculture Victoria
provides identification tools on the external website and a reporting line to the High Risk Invasive
Animals team for sightings of the Asian black-spined toad.
Recent work published by the University of Adelaide and the Department of Economic Development,
Jobs, Resources and Transport has shown that introduced amphibians, like the Asian black-spined
toad, have the potential to introduce rana virus. This disease of amphibians has the potential to
cause significant damage to native amphibians.
Feral horses
Populations of wild horses, also known as brumbies in Victoria, occur in the Barmah and Alpine
National Parks, although they also occur on other public land in the greater Alps.
The estimated feral horse population in the greater Australian Alps is approximately 9500. The main
Victorian population (est 3,800) is in the Eastern Alps. A smaller, isolated, population of around 50
animals occurs on the Bogong High Plains, and there have also been occasional reports of feral
horses in the Moroka River headwaters. All populations occur in both the Alpine National Park and
adjacent State forest, as well as nearby freehold land. The eastern Alps population extends into
Kosciuszko National Park in NSW. Small numbers of horses have been removed since 2005, but not
at a sufficient level to reduce overall growth of the population.
The Barmah National Park population is estimated to be around 150 with no active management
being undertaken at this time. Options to manage the impacts of this population are being
considered in partnership with the Yorta Yorta people and the Traditional Owner Land Management
Board under the joint management arrangements that apply to the park.
Both parks are rich in natural and cultural values susceptible to the impacts of horses. The
environmental effects of feral horses include soil loss, compaction and erosion, trampling of
vegetation, reducing plant species richness, inducing mortality of native trees, damage to peatland
habitat and water bodies and weed dispersal. Feral horses (mainly stallions) also occasionally harass
or threaten park visitors and can pose a risk to vehicles on mountain roads. There has been a 90%
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reduction in extent of Moira Grass at the Barmah Forest Ramsar site, constituting a potential change
in the ecological character of this site.
The impacts of feral horses in these locations is being investigated to identify the nature and scale of
any response required to manage any impacts and the appropriate control techniques available.
Parks Victoria is leading the development of strategies to manage the impacts of feral horses in both
Parks in close consultation with community representatives, Government and experts in relevant
fields. This work is being completed in recognition of the place feral horses hold in Australian
folklore and our obligations to protect National Parks for current and future generations.
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