The black bream survive ok in fresh water... I was amazed at how they could change from salt water to fresh water. I caught some of my black bream in the local swan and canning river here in Perth, it's more of a tidal estuary, basically just sea water.. After catching them with the rod, I stuck them straight into a tub of water with a battery powered air pump...
Once finished for the night I headed home and place the tub into the fresh water tank I had at home. I splashed a few cup fulls of water from the fresh water tank into the plastic tub every couple of minutes, adding more and more each time while watching the state of the bream. After about 10 minutes I flicked a fish out of the tub into the fresh water tank and it swam away.....
So then I tipped the whole lot into the fresh water tank, and suffered no problems at all, not one death....
I had them in there for quite some time until a bad power failure when I lost them.... They aren't as tough as some of the other species that have been mentioned around here, and they are VERY slow growing when compared with other available species... Which is a bit disapointing as they are a great fish to catch and eat.....
Have been and checked out the department of fisheries website and found nothing.... 
Tried ringing them and got an answering machine...