It's a man made freshwater lake and it would have to be a very determined/motivated shark to jump all the dams to get up here. The SCARIEST things we've got for toes are gar, water moccasins, and snapping turtles. The WORST things in the lake for toes are empty beer cans, broken glass, rusty nails, fish hooks....you know...the regular flotsam & jetsam.
But I wouldn't be too terribly surprised if we had a stray alligator or two around here...