Invasive species cost us a great deal globally

Photo: Pixabay/wal_172619

Invasive species have been wreaking havoc with ecosystems worldwide and a new report by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) details the grave extent of the harm these species inflict.

In all, more than 37,000 alien species have been introduced by human activities over the centuries into new habitats with more and more invasive species being introduced each year. Of this around a 10th, or over 3,500, can be classified as harmful.

The “Invasive Alien Species Assessment: Summary for Policymakers” by IPBES, which has 143 member states, explains that in addition to dramatic changes in biodiversity and ecosystems, the global economic cost of invasive alien species exceeded $423 billion annually in 2019, with costs having at least quadrupled every decade since 1970.

In the United Kingdom alone, aquatic water weeds like floating pennyworts and Japanese knotweeds  as well as alien species such as gray squirrels, minks and parakeets cost the country some £4 billion a year in economic losses.

“Annual estimated costs in 2021 were £3.02bn, £499m, £343m and £150m to England, Scotland, Wales and Northern Ireland respectively,” a team of scientists said recently on their findings.

“The cost to forestry increased eightfold, the cost to aquaculture and agriculture increased by 139.5% and 112.7%, respectively, and the cost of most of the other sectors increased roughly in line with inflation (47.6% for GB and 55.7% for Northern Ireland),” they add.

The authors of the IPBES report have found equally oversize impacts.

“We found that the impacts are huge and bigger than we expected,” stresses Martín Nuñez, a coordinating lead author of the chapter covering the impacts of invasive species who is an assistant professor of biology and biochermistry at the University of Houston.

A third (34%) of the impacts of biological invasions were reported from the Americas while nearly as much (31%) from Europe and Central Asia with a quarter (25%) from Asia and the Pacific and about 7% from Africa. Three-quarters of negative impacts are reported on with 14% in freshwater and 10% in maring habitats. “Invasive alien species are most damaging on islands, with alien plants now exceeding native plants on more than 25% of all islands,” the scientists report.

It is vital to take effective prevention measures, such as border biosecurity and strictly enforced import controls, to lessen these impacts, according to the scientists. Such measures have worked well in Australia, New Zealand and neighboring islands by reducing the spread of the brown marmorated stink bug, they note.

“Preparedness, early detection and rapid response are shown to be effective at reducing rates of alien species establishment,” the researchers write.

“Eradication has been successful and cost-effective for some species, especially when their populations are small and slow spreading in isolated ecosystems such as islands. For example, the black rat and rabbit have been successfully eradicated from French Polynesia.”