Aww man...
No sooner do I post the above message than I find this, which seems to debunk the theory that even sharks have long range electroreception. I was decieved by the "flashlight battery at 3000 yards" or whatever it was.
Because the bioelectric field created by the animal's heartbeat carries only over short distances, the shark's electroreception is effective only for finding objects that are very close to the shark's head.
http://www.jasonproject.org/jason7/c...um/sharks.html