phhh totally safe here then! It's only in warm lakes!! lol Newfoundland is too east, too cold and too windy for anything like that. I guess mom was right when she says NL is the safest place in the world (she's a little delusional but meh). Those amoeba affect and kill such a small number I'd be more worried about sun stroke or viral infections from nasty dirty things (children).
A leech got on me once. Only once and it was too small to do anything and flicked right off. But the lake we used to go to was in a very windy spot (anchored down our belongings with rocks and such). No such thing as stagnant! :p
But that stuff is a little freaky, amoebas and whatnot. You all should come to nl if you're paranoid! xD