This is why I don't swim in the ocean, lakes, ponds, rivers or anything else that isn't chlorinated. People say, "Oh, but the liklihood of it happening to you is so remote, how could you possibly be afraid of it?" To that I say, "Dude, this shark held on and left SEVENTY puncture marks, okay? It's not a chance I'm willing to take."
And yes, okay, there are no sharks in lakes and rivers and ponds, but do you know what there is? Big ass fish with teeth, blood suckers, and duck poo. I'd rather stick a fork in my eye than put one toe into water with living creatures in it.