I disagree that jumping out of ones environment is a smart move, especially if you don't know what's on the other side. I disagree that dolphins are dumb because they get caught in nets because: a) how do you jump over a net if you find your self in the absolute center? b) maybe most do 'just jump over' and the ones caught are the dumb few. c) if a dolphin doesn't jump over a net it will become sushi, a dolphin probably doesn't know that it should jump over a net unless it knows it's dangerous, if a dolphin knows the net is dangerous - it's probably already been caught (see sushi statement). d) nets (i think) are designed to be fairly invisible, dolphins aren't known for having excellent eyesight and I don't know if their echo location is good enough to spot a net... Let's have a fish off and stick a dolphin and a goldfish in a tank and see who wins... actually to make it fair lets stick quite a few goldfish in there...