There is an electrical barrier to stop carp from coming through to the great lakes:

You don’t need to watch the video as it doesn’t answer my question, but here

small fish are fine, birds are fine, but carp get shocked and just knocked out. Humans would probably die of cardiac arrest.

If it’s the same current per second or whatever, how are small fish not affected but big fish are? How is there a “greater that 50% chance” that a human would die if birds are just fine (and small fish lol).