When you get as old as I am, you realize that this is just more environmental hysteria. All creatures emigrate. Just because they hitch a ride with humans doesn't make it unnatural.
I’ve read that Zebra mussels are causing major problems in the Great Lakes. On the other hand while there was a big flap in the mid Atlantic region about “Frankenfish” (snakeheads?), there has not been much in the news about them recently.
Funny how the very same alarmists regarding invasive species are the ones that welcome an invasion from the other side of our southern border.