* Really fish do get fried if they happen to be in the area of the strike, but because the ocean is vast and lightning is dispersed into the water for only a very short distance, most fish are only stunned. If lightning was able to travel in water and not be dispersed would you want to go to the beach?
* Salt water is a very poor conductor of electricity. Therefore the charge does not go far at all.
* Who keeps thinking salt water is a poor conductor of electricity?! Salt water is a GOOD conductor of electricity! Pure water (meaning ONLY hydrogen and oxygen molecules) is a poor conductor. The reason salt water is a good conductor is due to the charged ions from the salt (Na+ and Cl- ions). You may be thinking "then why can I be electrocuted at home if we don't have salt water?" Well it's because your home water isn't exactly pure - there are several other ions and minerals in it.
* They do. Every year around 7000-10000 lightnings strike the sea around the world (This number is low since salt water is a poor conductor and attractor of electricity) and and when this happens most of Earth's marine life dies. Luckily fish are are fond of sexual intercourse and the sea life grows to its peak numbers around summertime.
* Ask anyone who has been shocked and they will tell you that salt water is a very good conductor since our bodies are mostly salt water; poor attractor, great conductor. Salt water fish/wildlife do not just make up for thier loss by having a reproductive free for all, it takes years to replace damage to any part of a reef system. Most lightining strikes happen in open water where there is almost no damage the the ecosystem and whatever fish is hit is not fried but boiled.
* There are conductors, semi-conductors and insulators in this world. While fresh water is a good conductor due to the impurities in it, salt water is only a semi-conductor and the lightning dissipates faster than it does in fresh water. But even in fresh water the lightning only travels so far before it too will dissipate.