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Indicator: BD-09 The change in extent of selected nationally significant invasive species

Data

Naturalised terrestrial and freshwater animal species

Over 80 species of exotic vertebrates (excluding marine species) have established wild populations in Australia. These species include:

• 25 mammals;
• 20 birds;
• 4 reptiles;
• 1 amphibian; and
• 23 freshwater fish on mainland Australia;
• plus 1 mammal, 7 birds and 2 reptiles on offshore islands

Naturalised terrestrial plant species

Over 28 000 foreign plants have been introduced to Australia and over 2 500 species have established in the wild, and may threaten the integrity of valued places, such as Kakadu National Park.

The per cent of Australia occupied by each of the top 20 weeds

Weed	Percent
Bitou bush	3
Blackberry	9
Gorse	3
Lantana	5.1
Mimosa	1
Parkinsonia	12.4
Parthenium	5.6
Prickly acacia	2.3
Rubber vine	7.7
Serrated tussock	2.2
Willows	0.8
Alligator weed	0.4
Athel pine	1
Bridal creeper	5
Cabomba	0.5
Chilean needle grass	0.2
Hymenachne	1
Mesquite	5.3
Pond apple	0.4
Salvinia	5

Source: Sinden, S Jones, R Hester, S Odom, D Kalisch, C James, R and Cacho, O 2004, 'The economic impact of weeds in Australia', in, (ed), Technical series No. 8, CRC for Australian Weed Management, Glen Osmond, SA.

What the data mean

While there are data on the current distribution of a number of introduced species that are perceived to be invasive, there are at present virtually no data on changes in distribution which might alert the community either to an increased risk that an introduced species may be becoming invasive, nor to any increase in area under threat from a species that is perceived to be invasive.

Data Limitations

The general distribution of many invasive species is easier to obtain than the actual numbers, density or rate of spread. Reporting on the full range of introduced wild species is resource intensive.

The indicator assumes that some species are invasive, and tracks their distribution. It sheds no light on whether or not they are, in fact, impacting invasively on the ecosystems in which they are naturalised, nor, if so, the extent of their invasiveness.

Issues for which this is an indicator and why

Biodiversity - Pressures on biodiversity - Invasive species 

Where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion

Other indicators for this issue:

• IW-37 Examples of carp pressures and measures for removal and/or commercial catch 
• IW-38 Cane toad distribution 
• IW-39 Examples of significant wetland weeds 
• BD-10 Examples of native species whose populations have declined where various invasive species have established resident populations 
• LD-19 Land use and land use change 
• LD-20 Total grazing pressure relative to net primary productivity 
• LD-35 Temporal and spatial correlation between changing fire regimes and species change 
• LD-40 Current research into pressures and contributions of naturalised introduced species 
• BD-13 Examples of the impact of grazing on biodiversity 

Land - Direct pressure of human activities on the land - Species introduction and species change 

Modification of the terrestrial environment, whether for agriculture or urban development of any other human purpose, involves removing resident species and introducing new species. This intentional unbalancing of ecosystems can cause some species in the modified environment to become invasive. While it is difficult, on the basis of any available data, to establish whether and how invasive any species might be in the wide range of environments and ecological communities across Australia, changes in distribution and population of one species may be an indicator of more profound ecological changes. Additionally, where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion.

Other indicators for this issue:

• LD-01 The proportion and area of native vegetation and changes over time 
• LD-19 Land use and land use change 
• LD-40 Current research into pressures and contributions of naturalised introduced species 
• LD-20 Total grazing pressure relative to net primary productivity 
• LD-35 Temporal and spatial correlation between changing fire regimes and species change 
• BD-12 Examples of the impacts of fires on biodiversity 
• BD-13 Examples of the impact of grazing on biodiversity 
• IW-37 Examples of carp pressures and measures for removal and/or commercial catch 
• IW-38 Cane toad distribution 
• IW-39 Examples of significant wetland weeds 
• BD-10 Examples of native species whose populations have declined where various invasive species have established resident populations 

Inland Waters - Response of biota - Invasive species 

Modification of freshwater environments for irrigation, extraction, storage, recreation, or any other human purpose, can involve removing resident species and introducing new species. This unbalancing of ecosystems can cause some species in the modified environment to become invasive. While it is difficult, on the basis of any available data, to establish whether and how invasive any species might be, changes in distribution and population of one species may be an indicator of more profound ecological changes. Additionally, where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion.

Other indicators for this issue:

• IW-37 Examples of carp pressures and measures for removal and/or commercial catch 
• IW-38 Cane toad distribution 
• IW-39 Examples of significant wetland weeds 
• LD-40 Current research into pressures and contributions of naturalised introduced species 
• BD-10 Examples of native species whose populations have declined where various invasive species have established resident populations 

Coasts and Oceans - Direct pressure of human activities on coasts and oceans - Pressure of fishing 

Species can be introduced to an ecosystem from fishing activities, especially, potentially, aquaculture. While it is difficult, on the basis of any available data, to establish whether and how invasive any species might be, changes in distribution and population of one species may be an indicator of more profound ecological changes. Additionally, where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion.

Other indicators for this issue:

• CO-16 Status of Australian fisheries 
• CO-17 Change in species and trophic structure of fish species caught 
• CO-19 Estimated tonnage taken by illegal fishing; estimated number of illegal boats, estimated number of individuals of threatened species taken 
• CO-20 Non-target effects: Area of seabeds trawled 
• CO-21 Non-target effects: Number and/or weight taken as bycatch, and change since introduction of exclusion devices 
• CO-22 Aquaculture: extent of habitat disturbed or removed 
• CO-23 Aquaculture: volume of discharged sediments and nutrients 
• CO-24 Aquaculture: origin species and tonnage of stockfeed used 
• CO-25 Aquaculture: instances of disease and exotic species introduction from movement of live material 
• CO-32 Number of injuries to marine animals from marine debris 
• CO-53 Evidence or examples of noise or visual disturbance of marine species by human activities 
• CO-62 Estimated number of marine animals harvested by recreational fishers 
• CO-63 Estimated number of marine animals harvested by indigenous fishers 
• CO-65 Correlation between various human activities and introduction of coastal and marine species 
• AAT-19 Annual catch in tonnes of marine species harvested in Australian Antarctic and sub-Antarctic waters - legal and illegal 
• AAT-20 Fishing by-catch numbers and/or weight taken as bycatch 
• LD-40 Current research into pressures and contributions of naturalised introduced species 

Coasts and Oceans - Direct pressure of human activities on coasts and oceans - Direct pressures of harvesting non-living materials 

Species can be introduced to an ecosystem from exploration rigs. While it is difficult, on the basis of any available data, to establish whether and how invasive any species might be, changes in distribution and population of one species may be an indicator of more profound ecological changes. Additionally, where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion.

Other indicators for this issue:

• CO-26 Extent of potential habitat disturbance by well rigs sites, pipelines etc 
• CO-27 Number, frequency, extent and volume of oil spills from all sources 
• CO-32 Number of injuries to marine animals from marine debris 
• CO-48 Area disturbed/potentially disturbed by seismic surveys 
• CO-53 Evidence or examples of noise or visual disturbance of marine species by human activities 
• CO-64 Quantity of various substances discharged by offshore extraction activities 
• CO-65 Correlation between various human activities and introduction of coastal and marine species 
• LD-40 Current research into pressures and contributions of naturalised introduced species 

Coasts and Oceans - Direct pressure of human activities on coasts and oceans - Direct pressure of coastal activities (other than shipping and fishing) 

Species can be introduced to an ecosystem by various types of coastal activities. While it is difficult, on the basis of any available data, to establish whether and how invasive any species might be, changes in distribution and population of one species may be an indicator of more profound ecological changes. Additionally, where there is a concern that a particular species is behaving invasively, changes in its distribution may signal an increase in area at risk, either from the species itself, or from the environmental modifications that are favouring its expansion.

Other indicators for this issue:

• CO-27 Number, frequency, extent and volume of oil spills from all sources 
• CO-28 Quantity of discharges of different substances from humans activities to coastal and marine waters 
• CO-29 Change in area of coastal potential acid sulphate soils under development for human use 
• CO-30 Length and area of coastal and estuarine foreshore altered for human purposes 
• CO-32 Number of injuries to marine animals from marine debris 
• CO-44 Marine chlorophyll concentration 
• CO-46 Comparative water quality of coastal lakes and lagoons (water quality gradient from north to south) 
• CO-53 Evidence or examples of noise or visual disturbance of marine species by human activities 
• CO-60 Sea salinity 
• CO-65 Correlation between various human activities and introduction of coastal and marine species 
• IW-12 Catchment nitrogen and phosphorus load 
• HS-05 Total population and distribution 
• IW-19 Exceedance of total nitrogen and phosphorus water quality triggers 
• LD-40 Current research into pressures and contributions of naturalised introduced species 
• BD-10 Examples of native species whose populations have declined where various invasive species have established resident populations 

Further Information

National Introduced Marine Pest Information System

• National Introduced Marine Pest Information System 

Weeds Australia’s WONS list

• Weeds Australia’s Weeds of National Significance list 

Weeds Aust noxious weeds database

• Weeds Australia Database - Noxious weeds list 

Cane toads

• Cane Toad Site 
• Weed categories for natural and agricultural ecosystem management 
• CRC Weed Management - latest publications 
• Pest Animal Control CRC - Publications and Presentations 
• WWF Australia - Weeds, Pests and Diseases 
• Australian Weeds - their ecology and management 

Invasive Species

• Invasive Species

Australian Terrestrial Biodiversity Assessment 2002

• Australian terrestrial biodiversity assessment 2002 

Review of Progress on Invasive Species

• Review of progress on invasive species

Senate document -Turning back the tide-the invasive species challenge

• Senate document -Turning back the tide-the invasive species challenge 
• Introduced marine pests
• Invasive Marine Species 
• National priority pests: part II ranking of Australian marine pests
• WWF - Australian Biosecurity Group: Invasive Weeds, Pests and Diseases 
• WWF- The Costs and Benefits of a Proposed Mandatory Invasive Species Labelling Scheme 
• Agricultural Pests and Feral Animals 
• Invasive Species National Projects
• Cost effective feral animal exclusion fencing for areas of high conservation value in Australia
• Review of existing Red Fox, Wild Dog, Feral Cat, Feral Rabbit, Feral Pig, and Feral Goat control in Australia. I. Audit
• Review of existing Red Fox, Feral Cat, Feral Rabbit, Feral Pig and Feral Goat control in Australia. II. Information Gaps
• Interactions between feral cats, foxes, native carnivores, and rabbits in Australia
• A preliminary risk assessment of cane toads in Kakadu National Park
• Facts and figures - environmental and agricultural weeds