Invasive plants and animals: introduction
Queensland is home to many plants and animals that have been introduced, either deliberately or accidentally, since human settlement. Some of these species have become invasive-that is they have spread and multiplied to the point where they can cause damage to the environment, the productive sector and human health and recreation.
This chapter examines the major environmental, social and economic problems associated with Queensland's invasive terrestrial animals, terrestrial plants, freshwater plants and animals, and marine plants and animals. Most of the issues have been discussed in previous state of the environment reports. Some previous indicators have been modified, and new ones have been included to align with national indicators.
Terrestrial pest animals cost Queensland at least $110 million a year through predation of livestock, crop losses, competition for pasture and the spread of disease. They also impose uncosted impacts on the environment through overgrazing, predation, competition and poisoning. Some pest animals can pose risks to human health and public safety in urban areas by spreading disease and becoming traffic hazards. Most exotic vertebrate pests have long been established in the state and have broad distributions. Eradication is not feasible for these species, so their management must focus on restricting their spread, preventing new introductions and controlling their impacts. Control needs to be sustained and well coordinated and target areas of high actual or potential impact.
Invasive terrestrial plants (weeds) cost Queensland an estimated $600 million a year in lost primary production and control. Weeds degrade the natural environment, decrease primary production, pose health and safety risks to humans and animals, and lower the aesthetic value of the natural landscape. More than 100 species of plants are declared weeds in Queensland, and seven of these are terrestrial Weeds of National Significance.
Freshwater systems are essential for life and underpin much of our social and economic wellbeing. Invasive freshwater pests can impair water quality, reduce the size of native fish populations and lower the aesthetic value of Queensland's waterways. Fishing, tourism and water treatment facilities can suffer adverse economic effects from invasive freshwater species. In 2004 red-eared slider turtles (Trachemys scripta) were found in south-east Queensland. This pest joins the 18 species of noxious fish and several declared aquatic weeds, including four Weeds of National Significance, that threaten Queensland's natural waterways.
Queensland 's marine environment is valued for its high-quality habitat, biodiversity and biological productivity. Several very profitable industries, such as fishing and tourism, rely heavily on the continued good health and aesthetic value of this natural resource. Currently, Queensland has no recorded established invasive marine pests. Hull fouling and the dumping of ballast water by ships present major pathways for the introduction of marine pests, however.
The Queensland Government, working with local governments, natural resource management groups, landowners and industry, is supporting research and developing management plans to reduce the impacts of invasive species on Queensland's environment, economy and society.
A major boost in the battle against invasive species was the establishment on 1 March 2007 of Biosecurity Queensland as a business group within the Department of Primary Industries and Fisheries. Biosecurity Queensland will be the single state agency responsible for research into, response to and management of invasive species in Queensland.
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Last reviewed 16 May 2011
Last updated 13 February 2008