Pest animals have significant economic, environmental and social impacts.
They have the potential to adversely alter ecosystem function, reduce primary industry productivity and profitability, and threaten human and animal health.
Pest animals reduce the viability of primary industries, which account for a significant proportion of Queensland´s export income.
The impacts of some animals are well documented; however, the true cost of pest animals to Queensland's economy is unknown and difficult to quantify.
Feral pigs alone have been estimated to reduce grain production by $12 million a year.
Wild dogs cost $33 million a year in livestock losses, diseases spread and control.
The cost of each mouse plague is estimated at $10-$20 million in lost agricultural production and $1.5 million in landowner and goverment control.
Negative economic impacts of pest animals include:
- direct control and management costs
- predation of livestock by wild dogs, foxes and feral pigs
- competition for resources
- destruction of natural resources through soil disturbance and removal of vegetation
- destruction of pastures and crops
- creation of general nuisance in urban and rural residential areas and associated management
- reduction of nature-based tourism due to destruction of natural resources.
Many pest animals are susceptible to, and could act as carriers for, a range of exotic diseases including foot-and-mouth, African swine fever and rabies. If these diseases were to enter Australia they would affect livestock and humans, and the cost of control and management would be considerable.
Introduced pest animals place considerable pressure on native plants and animals. While some impacts have been well documented, the true impact of pest animals on Queensland's environment is unknown and difficult to quantify.
Negative environmental impacts include:
- direct predation on native fauna - foxes and feral cats have been implicated in the decline or extinction of at least 17 native species
- destruction of habitats and natural resources including reduction in water quality, increased soil erosion and land degradation, and destruction of native plants that provide food and shelter to native species
- competition with native animals for food and shelter
- poisoning of native animals and spreading disease - the decline of native predators has been attributed to poisoning from cane toads.
Some pest animals impact on specific habitats or species; others are more general and affect many species, ecosystems and ecological and physical processes.
These impacts can lead to reduced populations of native species, a decline in the quality and quantity of their habitats, and ultimately the extinction of some native species.
The social impacts of pest animals are many and varied and can cost individuals and the government considerable sums of money.
Pest animals can create a general nuisance and interfere with the livability of an area, particularly in urban and rural residential areas.
Negative social impacts include:
- potential and actual disease transmission
- predation of, and attacks on, domestic poultry and small pets
- creation of dangerous driving conditions - pest animals often wander onto roads, and locust swarms reduce visibility
- reduction of the community's enjoyment of natural areas
- general nuisance and disturbance in urban areas.