I think they could use those big ponds out the end of the Port of Brisbane as a fish farm!
They could give people jobs and make a profit from the unused ponds.
Then when they reclaim some space for the port they can move the ponds further out.
Not only that but it is a Port!
They have already proven to hold and keep snapper.
I mean countries like Vietnam and Thailand use every thing they got, if a farmer has a dam he grows fish and catches frogs, if he has yard space he grows mushrooms in straw and sells them.
Do a google on it and you will see the huge salt dams they have.
Dan