I don't like to use the pumps.

First, in the hands of the untrained, you can kill a fish.

Second, a fish has been feeding for hours and it is caught. The fish's stomach is pumped, now it has to start over. The energy loss for the fish could be dangerous.

I won't use one. I just use a bug net and find out what is in the river. The fish HAVE to be eating that.

That's just my opinion......