Australia and New Zealand have either ministries or departments—I get confused as to which one is which—of biosecurity that serve to coordinate efforts to deal with species that are crossing their borders, whether we're talking about pathogens, species that affect threshold ecosystems, or aquatic invasive species, whether freshwater or marine. They coordinate these activities.
I can't say much more about it than that, except that their decisions are based largely on risk assessment. Their scientists probably lead the field as far as risk assessment methods go—that is, in abilities to identify which species or vectors pose the greatest risk, which ones will likely cause the greatest damage and so on.