Have a look at the photos I posted on the previous page BondyWhilst on this topic, Fisheries Officers with a fish biologist have been seen in Somerset Dam using electric stun gun to float fish to the surface. This serves two purposes. Collecting declared pest fish to dispatch in one bin and another bin was used to place non pest fish to recover and release.
The main reason why Fisheries does not want people to take tilapia home is that their offsprings/ babies can survive up to 48 hours out of water, this was aired on Brisbane TV channel sometime this year.
That might have something to do with fishers cutting the head of tilapia and dumping back in the waterway. I'm not sure if tilapia are mouth brooders, hence the 48 hour survival.
I could be wrong but that's basically what I heard and seen on TV.
Cheers, Bondy