The Economic Costs of Invasive Species / Australia

Over the years I have written about feral animals eg. rabbits, foxes, cats and exotic plants eg. blackberry, fireweed, bitou bush that have ‘arrived’ in Australia and caused severe economic and environmental damage to the country.
According to research that has painted the most accurate picture yet of the economic burden of these invaders, exotic plants, animals and diseases have cost Australia at least $390bn in damage and management costs over the past 60 years.
Feral cats are the costliest of the hundreds of individual species studied, accounting for just over $10bn in damage and management expenses. Rodents, pigs and rabbits came close behind.

But plants are the most damaging class of invasive pest.
Known costs to productivity and money spent managing species like ryegrass, parthenium and ragwort amounted to more than $200bn.
The actual financial burden is likely to be far higher, the scientists who led the study said, because only costs reliably reported over past decades were included.
The study did not attempt to put a figure on the environmental damage from invasive species, such as the loss of biodiversity, the extinction of species or  the loss of cultural values.
The study indicated that costs from invasive species were only likely to increase in the absence of major investment and better coordination.
In the 1970s, the average annual cost from invasive pests was $70m but in the most recent decade, this had risen to $20bn.
For New South Wales and the ACT, cats, foxes and rabbits had caused the most damage.
In the Northern Territory, more than a third of the costs came from a fungus that causes banana freckle disease.
Queensland’s costliest invader, according to the study, is the red fire ant with the potato weed the most expensive for Victoria and South Australia.
Tasmania’s biggest economic impact came from the toxic ragwort and Western Australia’s costliest invader is ryegrass.

But there were still very large gaps in understanding. For example, there were few studies or reports documenting damage from invasive birds, mites or fish.
Another was root rot which causes huge environmental and agricultural damage, but any good cost data couldn’t be found even though it is known that the impact is huge.
Last year, a report led by the CSIRO called for a major overhaul of the way Australia manages biosecurity threats.
With a rise in globalised travel and trade, the number of interceptions of potentially hazardous materials at Australia’s borders rose 50% between 2012 and 2017.
About 20 new weed species establish in Australia every year, and the broader management costs and production losses because of invasive weeds is estimated at $5bn a year, the CSIRO report said.
Andrew Cox, chief executive of the Invasive Species Council, said the study showed “the massive burden being borne by all parts of society” from pests and diseases.
Cox also said: “We are highly vulnerable – not just our natural environment but also our agricultural systems.
The ocean border is a natural defence but the escalating trade and travel is exposing us to risk. There are species already here whose impacts are growing and the rates of new arrivals are growing too.”

Source: The Guardian Australia