They will be destroyed like any other illegal fishing vessel.
I don't think that is straight forward to do.
The below articles are from several years ago, however it details how Chinese fishing vessels moved into the Galapagos. They stayed outside the EEZ, but then stripped fished on the very peripheral edge. Australia would have no ability to seize vessels that operated like this outside of war.
These fishing vessels are blue water sea going and can do speeds in the high teens, early 20s. They can be run down by a frigate on on full gas turbine, but nothing really else. A cape has no chance, an Arafua would be useful for patroling, but its a big area.
Now China picks on places like Ecuador because they have minimal ability to fight back. But they could equally park a large fleet 200nm off the coast of Broome or Abrolhos and permanently leave it there. We would have no ability to deal with that, other than perhaps watch it.
How China Targets the Global Fish Supply (Published 2022)
'They will be back': How China's 'dark' fleets are plundering the world's oceans