France Media AgencyApr 01, 2021 11:23:21 AM IS
Disease-transmitting mosquitoes, rodent-eating rodents, forest-eating insects and even domestic cats are “exotic” invaders whose costs to humans and the environment are enormous and are increasing, according to a comprehensive study published on Wednesday. Researchers in France estimate that invasive species have cost nearly $ 1.3 trillion to the global economy since 1970, averaging $ 26.8 billion a year. And they warn that this is likely an underestimate. In a study published in the journal Nature, scientists rounded up the dizzying harmful effects of species that are transmitted between habitats, whether plants, insects, reptiles, birds, fish, molluscs, microorganisms or mammals.
According to estimates by IPBES, there was a 70 percent increase in invasive species in the 21 countries studied since 1970.
Beyond the “phenomenal scale” of these costs, there are also signs of a steady upward trend since 1970, said lead author Christophe Diagne of the Laboratory for Ecology, Systematics and Evolution at the University of Paris-Saclay.
Most of the price is related to damage to ecosystems, crops, or fisheries, although pest control measures were also included in the study, an analysis of hundreds of studies that are part of a new invasive species database.
A preliminary summary of the ten most common invasive pests includes herbivorous rats and the Asian gypsy moth, which attacks trees across the northern hemisphere.
This included the tiger mosquito native to Southeast Asia, which has become one of the world’s worst invasive species and carries diseases such as chikungunya, dengue fever, and zika.
The average annual cost triples every decade, according to the researchers, in part due to the increase in scientific studies on the subject.
But there is also evidence of an “exponential increase in introduced species due to growing international trade,” said Franck Courchamp, director of the same Paris-Saclay laboratory.
“We import many species voluntarily or involuntarily,” he said.
Mussels in
It is a problem with a long history associated with human trade, travel, and colonialism.
In Australia, wild European rabbit populations were first reported in the early 19th century, and their population exploded, reaching such levels that it devastated native species and caused billions in crop damage.
In 1950 the government published the disease myxomatosis, which affects only rabbits and kills over 90 percent of wild hares. But some have since built up immunity.
The brown tree snake has eaten almost all of Guam’s native birds and lizards since it was accidentally introduced from its South Pacific habitat in the mid-20th century, causing power outages by infiltrating electrical systems and threatening people inside their homes.
In the 1980s and 1990s, the zebra mussel, which originated in the waterways of the former Soviet Union, invaded the Great Lakes of North America, blocking pipes, threatening native species and causing billions in damage.
On land, American forests – and more recently those in Europe – have been devastated by the Asian longhorn beetle.
While in Hawaii, the Puerto Rican coqui frog found a new home devoid of natural predators – with the exception of local homeowners, whose property values have fallen thanks to its deafening croak that can reach 100 decibels.
Incalculable
Researchers hope that by disclosing the cost of invasive species, they can raise awareness of the scale of the problem and put it on mankind’s daunting list of environmental problems.
Beyond the monetary estimate, the study said that the “environmental and health effects of invasions are at least as significant, yet often incalculable”.
The United Nations Scientific Advisory Board on Biodiversity, known as IPBES, has found that invasive species are among the top five contributors to environmental degradation worldwide, along with changes in land use, resource depletion, pollution and climate change.
According to estimates by IPBES, there was a 70 percent increase in invasive species in the 21 countries studied since 1970.
And the worst could come, said Courchamp, who is part of the upcoming IPBES research.
“International trade will result in more and more species being introduced, while climate change will result in more and more of these introduced species surviving and establishing themselves,” he said.
Early detection, better data, and preventive measures could cut costs significantly, the study says.
Courchamp said the domestic cat had a lot to answer for – among the worst, in fact, among the top ten researchers.
The animal, which has been around the world for hundreds of years, is now “invasive on almost every island in the world,” he said.
Domestic cats have been responsible for “most of the kills in the world of birds, reptiles and amphibians who are not prepared for these types of predators,” he added.
