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Biosecurity Risks in NSW

Biosecurity is important for the protection of the economy, environment and the community from the negative impacts associated with pests, diseases and weeds1. Invasive plants and animals cause significant damage to NSW primary industries, ecosystems, cultures and communities. The combined cost of invasive species across Australia is exceeds $13.5 billion annually in terms of the costs of management, control and economic losses2. Of this, the costs associated with managing weeds is around $1.8 billion annually and the economic losses associated with pest animals is around $170 million3.

Future Climate Change Impacts

Changes in biosecurity risks can arise from the introduction of new weeds, pests and diseases but also from changes in the suitability of environmental conditions that affect existing threats. Changes to the climate of NSW could allow new threats to emerge as conditions become more suitable for some species, while others may decline.

Research suggests that warmer conditions under climate change may mean that pests and diseases that would normally die back over winter (Buffalo fly, for example) may be able to survive and potentially thrive throughout the year. In contrast, climate change could also result in the decline of pests, weeds and diseases where upper temperature thresholds are exceeded, changing the distribution and severity of the risks in NSW.  As a general principle, all invasive plants will experience a southward range shift as temperatures in southern areas increase4. This will result in sub-tropical plants being able to spread into more southern areas, while temperate species will be displaced even further to the south.

Less frost tolerant species are expected to expand their range further south if allowed to establish5. This includes those species already present but restricted in NSW, such as trees (camphor laurel Cinnamomum camphora), shrubs (devils fig Solanum chrysotrichum), vines (cat’s claw creeper Dolichandra (syn. Macfadyena) unguis-cati)), grasses (aleman grass Echinochloa colona) and aquatic plants (Hymenachne amplexicaulis)6, and all weeds of sub-tropical production and environmental ecosystems north of NSW.

Vulnerability Assessment

While general assumptions on climate change impacts for biosecurity have been made and some pests and diseases modelled, there is a need to better understand the impacts of climate change on the pests, diseases and weeds that matter to key primary industries for NSW. To address this, the NSW DPI Climate Change Research Strategy is working to develop a comparable analysis of climate change impacts for a range of key primary industries and related biosecurity threats across NSW.

With the application of a consistent methodology, changes to biosecurity risks under climate change will be compared with anticipated changes to the commodities that they affect, providing an insight into the changing challenges or opportunities of commodities and related threats. Over the coming months, to June 2022, the Vulnerability Assessment Project will be carrying out research to provide a better understanding of the key biosecurity threats for primary industries as listed below.

In total, the Vulnerability Assessment project is looking at 14 different biosecurity threats relating to cropping, horticulture and livestock. These threats are as follows:

Crop Diseases

  • Verticillium wilt (Verticilium dahliae)
  • Wheat stripe rust (Puccinia striiforms f. sp. Tritici)
  • Wheat stem rust (Puccinia graminis f. sp. Tritici)
  • Stem rot (Sclerotinia sclerotiorum)

Invasive Weeds

  • Serrated Tussock (Nassella trichotoma)
  • Parthenium weed (Parthenium hysterophorus)

Horticulture Pests

  • Queensland Fruit Fly (Bactrocera tryoni)
  • Oriental Fruit Fly* (Bactrocera dorsalis)
  • Serpentine Leaf Miner (Liriomyza huidobrensis)

* not currently in NSW, potential future impact

Livestock Parasites

  • Culicoides biting midge (Culicoides brevitarsis (vector for Blue Tongue disease))
  • Cattle tick (Rhipicephalus microplus)
  • Blowfly (Lucilia cuprina)
  • Buffalo Fly (Haematobia exigua)
  • Barbers Pole Worm (Haemonchus contortus)


1 NSW State of Biosecurity, 2017

2 AAS, Australian Academy of Sciences (2019). Australia’s silent invaders. https://www.science.org.au/curious/earth-environment/invasive-species

3 NSW State of Biosecurity, 2017

4 McFadyen, R. (2007). Invasive plants and climate change. Briefing notes. Cooperative Research Centre for Australian Weed management, Adelaide

5 Navie, S.C., McFadyen, R.E., Panetta, F.D. and Adkins, S.W. (1996). The biology of Australian weeds. 27. Parthenium hysterophorus L. Plant Protection Quarterly 11, 76-88.

6 Boorman, D. (2009). Pasture grasses Hymenachne amplexicaulis (Rudge) Nees (hymenachne) and Echinochloa polystachya (Kunth) A.S. Hitchc. cv ‘Amity’ (aleman grass) and the potential for spread of invasive weeds. Proceedings of the 15th Biennial NSW Weeds Conference, 9 pp. Weed Society of New South Wales, Narrabri.