Invasive alien species exact huge ecosystem cost

A snowy coypu: Imported to Europe from Latin America for their fur, they are treated as pests for damaging marshlands. Image: A_Peach, via Wikimedia Commons

At last, a global price on invasive alien species: it runs to billions of dollars and doubles every six years.

LONDON, 8 April, 2021 − French scientists have put a value on the cost of ecosystem destruction by often almost invisible newcomers: the damage invasive alien species do, and the price of containing that damage, has already passed the US$1.28 trillion mark in less than 50 years.

That’s because the annual toll imposed by cats, rats and mice, boll weevils, gipsy moths, African bees, red imported fire ants and other unwelcome migrants has averaged $26.8 billion a year from 1970 to 2017, and has been doubling every six years, and trebling every decade.

Which is why the global economic losses in 2017 alone reached $162bn, and will go on rising, they warn in the journal Nature.

“This trillion dollar bill doesn’t show any sign of slowing down, with a consistent threefold increase per decade,” said Christophe Diagne of the Université Paris-Saclay, who led the research.

“Our very conservative approach is in fact a massive underestimation of the actual economic costs”

“Our annual global estimates signify the huge economic burden, with the average cost exceeding the gross domestic product of 50 countries on the African continent in 2017, and it’s more than 20 times higher than the total funds available for the World Health Organisation and UN combined.”

Displaced species − accidental stowaways such as the Norway rat and the malarial mosquito, or deliberate introductions such as coypu and mink
− can and do cause colossal damage to unique habitats fashioned by evolution and to the ecosystem services they provide.

African bees and boll weevils from Mexico present a potentially devastating threat to farm incomes worldwide; the larvae of gypsy moths from Europe − known to devour the foliage of at least 500 tree species − have caused devastation in US forests, and the colonies of the subterranean Formosan termite are now chewing their way through woodwork on mainland Asia and the US.

And, researchers warn, the expansion of global economic traffic, the degradation of natural habitat and the new opportunities delivered by climate change driven by global warming can only deliver more and more devastating opportunities for such invaders.

Models verified

Dr Diagne and his colleagues in Europe and Australia have been compiling a database of the economic costs of biological invasion, and a mechanism for calculating the scale of annual monetary losses. And these, the researchers warn, are probably much higher than $1.28 trillion in the last five decades.

They want to see the hazard of biological invasion taken seriously in the discussion of transnational projects. They also urge international co-operation to reduce the risks.

“The global costs of invasive alien species are so massive that we spent months verifying our models and this overall estimate, to ensure we were not exaggerating,” Dr Diagne said.

“As it turns out, our very conservative approach is in fact a massive underestimation of the actual economic costs.” − Climate News Network