We've been able to seine approx. 50% of tilapia with a short seine while pumping fresh water to a pond end and cutting them off as they huddle up around it. I suspect that may be possible by just pumping out and back in with a gas water pump, spraying the water back in the pond. Then just cut them off with a seine when you can see them. This wouldn't be a size-selective measure. Also might try carp dough bait, as you can ball it up on a hook fairly large and select for larger fish.
