We're literally heading towards reverting back to Gondwana Land with all species spreading as if there were no oceans.

Good morning my old mate indy, the sky is not falling mate
We are not all doomed the real world has its problems but rather be a road killed possum than any thing other than an Aussie
Cheer up bloke

Belly,
by reverting back to Gondwana I mean that with so much cargo movement nowadays it is literally impossible to prevent species settling everywhere. The uniqueness of species of continents is no longer applicable. The good thing is that animals will adapt. Why, because animals don't have religion to ruin it all for them.
That's why humans need to be kept behind walls to slow the spread of their stupidity because stupidity is what gets enhanced easier than any other human trait. Stupidity can spread via media, whereas no other decease can.
In case of the Cape York Quarantine Stations, it is stupidity that lets harmful products through into the rest of Australia, not the closed station.

One day, bank on it, some one will import a very real threat to our country's safe food rating
It in all probability will come in the suit cases of some mum and dad couple
Having got away with wrist slapping in the past they will take the risk again, and again
Unless we name the offense just what it is, a crime we will be in part responsible too

Belly,
The real threat is sabotage ! Political by the Left & economically by foreign interests operating here with immunity !

well you do live in another world old mate
thankfully one that never existed
if we had a subject heading about the biggest risk to this country my answer word be china we are however talking about a future possible loss of our clean and green food rating