Indicator Rationale 

Introduced pests and weeds have serious impacts on biodiversity and agricultural productivity.  Introduced animals compete with and prey on native animals. Two of the best known examples are foxes and rabbits.  Foxes (and feral cats) are responsible for pushing many small animals (5 grams to 5 kilograms) to the brink of extinction.  Rabbits have negative impacts on native vegetation and pastoral grasses, competing with livestock and causing economic losses.  Programs to control these two pest species are costly and eradication unlikely.   Weed species are also associated with large environmental and economic costs.  Weeds occur in both terrestrial and aquatic habitats, reduce biodiversity and are costly to control. 

In general, pest species have high reproductive rates and can tolerate a wide range of habitats.  As a result, they often establish populations very quickly, displacing native animals and plants.  Fungal pathogens are also a serious threat to native vegetation and susceptible crop species.  Certain weed species can also increase the risk of wildfire, may be toxic to livestock or render agricultural land useless (Government of South Australia, 2006).

Some of the environmental and economic effects associated with the spread of introduced species include:
• Loss of biodiversity, through predation, competition and disease
• Negative impacts on native plants and communities through predation and competition
• Negative impact on fisheries - introduced fish or other aquatic species prey upon or compete with native fish for food and habitat.
• Negative impact on native animals through predation and competition
• Losses in agricultural productivity.
• Costly to control

Data Source

Data sources are currently unavailable.

Measure

No measure currently available, must be explored further.

Reference

Government of South Australia (2006).  Biodiversity.  Introduced species.  Environment Reporting.