cowfish,

There are many animals, and many varieties of fish, that are affected in different ways by electrical fields. The Black Boxes so many anglers use is an example of taking advantage of a fish's reaction to electrical fields.

I watched a Discovery channel show about sharks once. In it, a Sand Tiger shark at an aquarium would swin around his enclosure, and veer into the wall at a certain location every time he went by. The shark's keepers were concerned by its behavior and looked into a possible cause. What they found was this. A tiny crack in the concrete enclosure had allowed the salt water to seep into the wall. When it reached the rebar inside, it began to corrode the steel and cause a minute electrical current. When the shark swam by, he zeroed in on the current, and would bash into the wall. They drained the tank, fixed the cracks, sealed the concrete, and the shark lived happily ever after. So yes, electrical currents do affect fish and their behavior.

I was speaking about possible genetic defects, or cancers, that EMF has been claimed to cause.

I should have been more clear in my response.