GWSUK
In addressing your post dated 06/29/08:
Your point about the blood, while interesting, doesn't apply to the MI scenario unless the seal / human happens to be wounded. Typically GW target seals by sight and sound not smell. A hypothesis as to why GW normally don't consume humans after an attack is once they taste us they don't like the flavor in much the same scenario as you presented with the Lemon Shark so this supports MI rather than wounding it.
GW knowledge? What sort of "knowledge" are you talking about? These are fish. Their BMI might be high relative to a goldfish but it is low even when compared to mice and cows. They do very poorly with Pavlovian training and their retention of said training is minimal to nonexistent. One of the big reasons we've had so much trouble keeping GW in captivity is their unswerving stupidity. In one case a GW kept bouncing into a wall because it detected a faint electrical signal in that area caused by a light mounted on the opposite side of the tank. It kept hitting the same place over and over and over again until it was severely injured and if it hadn't been released it would have repeated the behavior until it was dead so even after repeatedly performing the same action it didn't make a behavior / pain association which is one of the simplest of connections. You can hook a shark over and over and over and over again and it will never learn not to take the bait.
The GW's sensory system consists of the same senses you employ with the addition of the lateral line and electrical sensitivity. It has good sight but sight can be fooled especially when viewing a silhouette. It has excellent hearing as well as the lateral line system but these are tuned to locate prey that broadcast at 40 Hertz and it doesn't matter what is making the sound whether it is a fish, seal, human, or hydrophone. 40 Hertz = Prey. It has an excellent sense of smell but that typically only comes into play if the prey is injured and the electro sensitivity only works within a couple of meters and it only tells the shark if there is muscle activity not what sort of prey it is
While I agree that many attacks on humans may be intentionally predatory, curiosity, and territorial I don't think all or even most are (depending on the species).
I have seen the footage of Ritter's attack. It wasn't exactly a typical naturally occurring shark encounter, was it? Holding up Ritter's stunt as an example of shark aggression is ridiculous. What do you expect when you walk into a cage filled with lions and tigers wearing a necklace made out of steak medallions? The surprise is if you make it out. Same thing with Ritter. When you do something stupid you're eventually going to pay the price. In Ritter's case MI means "Moronic Idiot" rather than "Mistaken Identity." He did the same thing dozens if not hundreds of times and never got hit and these events didn't make Page E-36 below the underwear ads but the moment he got chewed it made front page world news so what little "good" he did (nil in my opinion) in all his previous stunts combined was - far - outweighed by the harm he did when he eventually got bitten. When you pen sharks and chum the water you are ringing the dinner bell and jumping onto a plate. The thing that amazes me is that he got away with it as long as he did. Any animal expert will tell you that when you're dealing with wild animals you will eventually end up on the wrong end of an encounter regardless of if we're talking about Roy from "Siegfried and Roy" getting gnawed on by a tiger, someone milking snakes, or loosing your calf to a Bull shark. Remember Steve Irwin? I don't think anyone was surprised when he ended up dead. The only thing that shocked people was the animal that finally got him. Croc? No big surprise. Snake? No big surprise. Sting Ray? You have got to be kidding. The sad part is some nutters decided to "avenge" him by killing a bunch of rays, many of which were the completely wrong species. Brilliant! Here's a basic rule for animal interaction: Do something stupid = Going to get hurt or dead. Forget this at your own peril.
The right tools for the environment is Evolution 101 but the right tools doesn't mean you can't be fooled. I have the right tools to make cereal in the morning but upon occasion I pour sour milk over the top of my Captain Crunch. I can smell the difference between good and bad milk but sometimes I'm not paying attention and I get a mouthful of yuck. If humans can screw up why not sharks?

