The European ecosystem is [censored] anyway. We didn't just eradicate any natural predators to a degree that we NEED to control wildlife population via hunting, we also introduced hundreds of exotic species and they um up to a level that exotic ants can barely make it worse than it already is.
You want a clean, preserved European ecosystem?
Good, first step, all parrots, parakeets and guinea pigs must be banned. If you want a bird as pet, just raise a sparrow or a crow.
Next, get used to wolves and bears which are slowly coming back after we stopped killing every single one trespassing central european ground.
Then we need to kill all the exotics we already have here. While raccoons and Nutrias might be difficult to kill off, it shouldn't be too hard to blast all those grey parrots out of the skies of Worms. Killing the Nandus in northern Germany shouldn't be too hard either. Chinese ducks are most likely easy targets as well. And there needs a massive eradication campaign against those parakeets all over Europe (including the northern UK).
Oh, and of course the american mustangs must die as well cause these horses are clearly not native to the american continent.
And don't even get me started on EXOTIC PLANTS IN EVERY DAMN GARDEN. We need to get flamethrowers and lay waste to pretty much every single village garden before these plants make the jump over the fence (which they are already starting to do in rapidly increasing numbers).
Oh, and good luck purging the european rivers and sees from exotics. That train departed decades ago.
History and science show what foreign/invasive species can do.
History and science have also shown that PRETTY MUCH EVERY SINGLE EXOTIC SPECIES has either been INTRODUCED VIA TRADING GOODS (mostly smaller mobile animals like insects, rodents, snakes) or where WILLINGLY IMPORTED BY GOVERNMENTS (mostly the lesser mobile species like cane toads in Australia, great nil persh to the Victoria sea, horses to pretty much every place where they exist)
Oh, and did I mention that pretty much every single agricultural plant is an exotic species?
So just because it's injured we should issue the final blow?