The heat generated from the average lightning bolt (negative charged ) is 5 times hotter than the surface of the sun.( 50,000 degrees F )Positive charged bolts can be 6-10 times hotter and more powerful. So in theory, it is possible to super-heat a small portion of a body of water and lead to the warming of the entire body of water as temps balance. I would think it is plausable that a body of water could be warmed enough to not support certain species of fish quite easily.
