Invasive species are a serious threat to endemic Australian species, and an ongoing cost to Australian agriculture. Numerous species arrived with European maritime exploration and colonisation of Australia and steadily since then. There is ongoing debate about the potential benefits and detriments of introduced species; some experts believe that certain species, particularly megafauna such as deer, equids, bovids, and camels, may be more beneficial to Australia's ecosystems than they are detrimental, acting as replacements for extinct Australian megafauna.
Management and the prevention of the introduction of new invasive species are key environmental and agricultural policy issues for the Australian federal and state governments. As of 2016 the management of weeds cost A$1.5 billion on weed control and a further $2.5 billion in lost agricultural production over the course of a year.
