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#Investigation: the phenomenal cost of invasive species

It is a danger for the planet that is still largely underestimated. Invasive alien species are a threat to biodiversity, but also to the economy. The annual cost has been estimated at more than 160 billion euros, worldwide.

In Belgium, the super invasive champions are called Asian hornet, tiger mosquito, Japanese knotweed or raccoon. Their spread quickly got out of control.

In just 20 years, raccoons have conquered all of Wallonia and would be between 50,000 and 75,000. The animal is of American origin: it was imported in particular by GIs who had made it their mascot.

“I caught more than 2000 in 18 months, explains Benoît Leuris, member of a team from the Walloon Region who installs cages to stop the proliferation of raccoons. The animal is a vector of rabies, it is also a carrier of a worrying disease, Baylis ascaris, which can be fatal for humans. That’s why you shouldn’t touch the animal’s coat.”

After capture, raccoons are euthanized by gunshot. A process that shocks some nature lovers. “We do not have the choice, continues Benoît Leuris. Despite his friendly face, the raccoon decimates the local fauna. It invades homes in search of food. It can attack pets. It is a fearsome predator.”

An Asian snake invades Flanders

In Hasselt, in Limburg, it is a 1m50 snake which frightens the local population. The rat snake is not dangerous but it breeds quickly along railway tracks. The first specimens to be found in the wild are said to have escaped 6 years ago from a store in the region specializing in reptiles.

“Now we can no longer sell this species in Flanders, explains biologist Loic van Doorn, because there is a free population. However, the snake is still on sale in Wallonia.”