EnviroNorth > All Regions > Biosecurity

Biosecurity in northern Australia

What is biosecurity?

Avian Flu Spread

The spread of Avian Influenza is a biosecurity threat to Australia: red countries have had birds killed by the virus, brown countries have also had hu8man deaths. Source wikipedia.

Biosecurity includes the strategies and methods employed to assess and manage the risk of introduction of infectious diseases, genetically modified organisms and pests into an area, including protection against bioterrorism threats. Biosecurity measures may include legislation, statutory agreements with neighbouring countries, surveillance, monitoring, quarantine and border patrol.


Why protect Australia’s biosecurity?


Many natural features of the savannas are relatively recent arrivals such as these Boab trees photo: Ian Partridge

There is nothing intrinsically alarming about organisms moving to Australia, as many of our native animals and plants came from somewhere else and “moved in”, as did we. However, most of these organisms arrived piecemeal over long stretches of time and while many had an initial impact the local ecosystems appear to have had time to adapt to these new arrivals. Even in the case of humans, who may have had major impacts when they first arrived, the local ecosystems have adapted and flourished for tens of thousands of years after their arrival.  The problem today is the sheer number of new organisms now entering Australia in a very short time.

In the last 200 years Australia has seen the entry of more than 2800 foreign plants, many of which have become weeds, hundreds of invasive animal species and many introduced diseases spread by organisms like fungi, and bacteria. Around 20 new pests or diseases enter Australia each year. Abundant evidence suggests our environments are being transformed by this invasion: 22 species of mammals have gone extinct with foxes, cats and rabbits heavily implicated in their demise; several endangered mammals now only survive on offshore islands where they are protected from predators like foxes and cats; weeds have degraded many millions of hectares of grazing and natural lands and have caused declines in many native plant species; disease caused by chytrid fungus is believed to be responsible for the extinction of seven frog species.

Beer is made from hops, Humulus lupulus, an introduced plant

Of course, this recent wave of new species has also been responsible for many of the things we value most: wheat, wool and beef have been important mainstays of the economy; beer, wine, bread, dairy products, fruit and vegetables are virtually all from introduced species; and last but not least, non-indigenous people, and most of their pets and many of their garden plants are all recent immigrants.





Feral Pigs and the Dangers of Disease

hoggolatFeral pigs can harbour or spread exotic diseases, the most serious of which are: Foot-and-mouth disease which can also affect cattle, sheep, goats and deer; Swine vesicular disease; African swine fever and Classical swine fever. These are all diseases that can affect domestic pigs. Aujeszky’s herpes virus and Trichinosus are also diseases that are mostly likely to impact on domestic pigs. Foot-and-Mouth Disease in particular could have disastrous consequences for Australian agriculture with estimated immediate loss of $6 Billion in export trade, plus $8 Billion for every day the outbreak lasted.

Feral pigs can carry more serious diseases than most animal pests, partly because they have a 10,000 year history of being domesticated farm yard animals, kept in groups. Jared Diamond in his book Guns, Germs and Steel points out that being held in groups along with other livestock like cattle led to the evolution of microbes that benefitted from this arrangement becoming diseases of livestock that could spread between cattle, sheep, goats and pigs as well as related wild species.

collecting pig blood samples

Indigenous Rangers taking blood samples from feral pigs to check for disease

A key to preventing an outbreak of an exotic disease from feral pig populations is continual monitoring for the presence of such diseases in the pigs. This is no easy task given that there are millions of feral pigs scattered in remote parts of Queensland the Northern Territory, New South Wales and the ACT with some also in Western Australia. One approach to this challenge is for Indigenous communities, particularly Indigenous Land and Sea Ranger groups, to work with the Australian Quarantine and Inspection Service (AQIS) by regularly harvesting feral pigs and inspecting them for the presence of serious exotic diseases like Foot and Mouth Disease.

Time Bomb: Mimosa pigra

That the downsides of some of these recent arrivals are now more obvious is in part because their impacts have often taken a long time to become apparent. For example, one of northern Australia’s most significant weeds, the giant sensitive plant, Mimosa pigra, started off as an introduced ornamental plant which was unnoticed in the landscape for many decades until it became a serious pest in the 1980s.  It is now apparent that impacts from introduced organisms are not only damaging the environment but damaging the economy. It is estimated that weeds cost the Australian economy $4 Billion a year and feral animals $720 million a year.

These costs are from pests and diseases already in Australia and while Australia enjoys a relatively high level of biosecurity due to its high standards of living, strict quarantine regulations and its geographic isolation, the costs could be much greater in the future if the influx of organisms is not addressed, particularly if pathogens like foot and mouth disease or avian influenza were to become established in Australia.

What are the future risks in Northern Australia?


An Anopheles mosquito that spread Malaria - the disease is widespread to Australia's north. Photo:

Northern Australia is particularly vulnerable to invasion from organisms beyond our borders: it has an extensive, sparsely populated coastline that is exposed to the sea-lanes to our north and it has a tropical environment that can support vigorous plant growth and harbour many animals. The following risks have been identified:

  • Spread of infectious disease such as tuberculosis through people.
  • Spread of mosquito-borne diseases such as the dangerous Ross river virus, dengue fever, Japanese encephalitis and malaria pose a serious risk to human health and can cause death. 
  • Introduction of avian influenza or “bird flu” virus, carried in poultry and wild birds poses a serious risk to Australia’s agricultural economy and a small yet significant risk to human health. 
  • Agricultural and economic cost of introducing pests carried in plant material such as fruit fly and termites.
  • Environmental cost of introducing other exotic animals such as cats, dogs and marine pests.

Emerging threats

Global warming 2

The years 1995-2004 have seen a warming trend as shown in these temperature anomolies (oC) with most regions showing above average temperatures. Global warming could enhance the spread of some diseases. Source:

The small population density of northern Australia means that if well-managed, the risks above are relatively small; however, they are of particular concern given the trends below.

  • An increasing number of illegal foreign fishing vessels entering Australian waters, mainly from Indonesia.
  • An increasing number of unauthorised land incursions from overseas, including refugees.
  • The change in distribution of pathogens within Indonesia due to eastern migration of communities.
  • Climate change is likely to cause global warming of 1.4-5.8 degrees Celcius by 2100.  This is likely to affect the distribution of vectors such as mosquitoes and ticks through changes in the distribution of rainfall, occurrence of extreme weather events and distribution of arthropod habitat.   Australia is likely to be at greater risk to the increased distribution and occurrence of some vector-borne and water-borne diseases including dengue fever, malaria, Ross River virus and diarrhoea because of a global temperature rise. Remote indigenous communities are particularly vulnerable to these diseases. The degree of impact of climate change upon the spread of vectors remains largely uncertain. 

 What should be done?

A number of elements are high on the list when it comes to maintaining biosecurity for northern Australia:

  • Strict quarantine regulations
  • Border patrol to detect illegal vessels
  • Treatment and destruction of illegal vessels potentially carrying pathogens and pests.
  • Quarantine of people and animals aboard a detained illegal vessel
  • Mitigation of climate change
  • Vigilant monitoring of areas most vulnerable in Australia through sampling of known potential vectors.
  • Mapping of the distribution of disease, pests and vector species

Many of these activities are already being undertaken in the north by AQIS – the Australian Quarantine and Inspection Service through its North Australian Quarantine Strategy (NAQS). Under this strategy AQIS is undertaking scientific surveys and monitoring, border activities, on and off shore capacity building and public awareness activities. Much of this activity involves collaboration with local Indigenous communities.

At the national level the Australian Biosecurity group, convened by the Invasive Animals and Weeds Cooperative Research Centres and WWF-Australia, consider that Australia’s biossecurity shield has a number of shortcomings that could be addressed by the following broad initiatives:

  1. National institutions (including a lead Australian Government body) dedicated to invasive species
  2. A coherent policy framework
  3. A strong regulatory framework
  4. A seamless and stream-lined response framework
  5. A national framework for prevention and early detection
  6. A national education, training and action program
  7. A national information system
  8. A fund for strategic research
  9. Equitable industry contributions to improve detection and eradication
  10. Cost-sharing arrangements to fund detection and eradication of both environmental and agricultural threats

Opportunities for northern Australia

The location of indigenous communities makes them well-placed to monitor Australia’s northern coastline. 75% of the area covered by the NAQS area is Aboriginal Land.  Indigenous people living along Australia’s north coast possess a detailed knowledge of their traditional country, including flora and fauna, tides and fishing grounds.

The Northern Land Council (NLC) has a partnership with AQIS to provide surveillance of the coastline. Indigenous Sea and Land Rangers also sample for pest plants and animals and detect outbreak of diseases in plants and animals.

Remote Indigenous communities have high unemployment rates due to lack of employment opportunities.   The common form of employment is through Community Development Employment Projects (CDEP), a form of work-for-the-dole.  Expanding monitoring of the NAQS area by Indigenous Sea and Land Rangers is an opportunity for people living in remote indigenous communities to receive training and employment.  Further employment opportunities associated with managing biosecurity risk, such as pest control, also exist.  Greater funding is needed for these programs so that wages for indigenous employees can be made equivalent to those of non-indigenous people employed by Customs and AQIS and to extend the Ranger Program to other communities.


Australian Biosecurity Group (2005) Invasive Weeds, Pests and Diseases: Solutions to Secure Australia, CRC for Pest Animal Control, CRC for Australian Weed Management and WWF Australia, Canberra.

Choquenot, D., McIlroy, J. & Korn, T. (1996) Managing Vertebrate Pests: Feral Pigs, Bureau of Resource Sciences, Australian Government Publishing Service, Canberra.

Marley, J., Armstrong, R., Morrison, J., and Yu, P. (2007) Indigenous Communities are Ideally Located to Monitor and Reduce the Biosecurity Risks Associated with Illegal Foreign Fishing and Climate Change in Northern Australia. NAILSMA discussion paper (see link above right).