Counting the cost of invasive species
Biological invasions — the introduction and spread of a species outside its native habitat — have resulted in at least US$1.288 trillion (2017 US dollars) in associated costs worldwide between 1970 and 2017, according to a study published online in Nature this week. One of the authors of the study was Ivan Jarić from the Biology Centre, CAS, who was involved in the work on data collection and standardization, as well as on the manuscript development.
Image above: Grey squirrel is native to eastern North America, but it was widely introduced to certain places around the world, especially Ireland, Britain or Italy, where it displaced the native squirrels. Photo Anna Turbelin
The introduction of invasive alien species can have negative effects on biodiversity, human health and the economy. The economic impacts can include losses of goods and services, as well as money spent on managing biological invasions. As globalization and climate change exacerbate the risk of these invasions, a reliable worldwide economic impact assessment is needed to quantify the associated costs.
Using the InvaCost database, Christophe Diagne and colleagues assessed the monetary impacts of invasions worldwide. The authors found that invasions are economically costly to human societies and estimate that they produced a minimum of US$1.288 trillion in losses and expenses from 1970 to 2017. Estimates suggest that the annual average cost trebled every 10 years over the study period, and the authors predict that the average cost may have exceeded US$47 billion in 2017. Invasive invertebrate species had the greatest economic impact, resulting in an average annual cost of US$8.7 billion over the period assessed. At the geographical level, North America was found to incur the highest costs as a result of invasive species (an average of US$11 billion per year).
The authors note that their analysis is based on reported costs and as such the estimates for certain geographies and species may be underestimated. They argue that international agreements are needed to reduce the economic burden of invasive alien species.
Red imported fire ants are among the worst invasive species in the world. Some scientists consider the red imported fire ant to be a "disturbance specialist"; human disturbance to the environment may be a major factor behind the ants' impact (fire ants tend to favour disturbed areas). Photo: Y. Aoyama
Diagne, C., Leroy, B., Vaissière, A.C., Gozlan, R.E., Roiz, D., Jarić, I., Salles, J.M., Bradshaw, C.J.A. and Courchamp, F. (2021). High and rising economic costs of biological invasions worldwide. Nature 592, 571-578. https://doi.org/10.1038/s41586-021-03405-6