If you’re talking about civil stuff, I know that the EPA said that if you knowingly import species like plants and animals, you can get fined up to $50k and have a sentence of a year. There are different levels of it. I think one act said you could be charged $25k and have a sentence of six months. I don’t remember the differences though. But that’s also mostly for illegal trafficking (i.e. international species distribution); I imagine that it would be pretty hard to find out if you actually did introduce an invasive species unless you’re actively searching. They do that on watercraft here, but if you’re going, say, into the backcountry with no help, chances are no one will find out and the species will end up spreading and people won’t find out about it until it’s too late.
Just out of curiosity, why are you asking about this?
