The shark is gone bad. Sharks are really terrific eating but because of high levels of uremic acid, they tend to go bad very quickly if not impeccably handled.
If you catch a shark and wish to keep it for eating, clean it immediately upon catching, make sure to wash each steak thoroughly, individually wrap and put them right on ice.
When buying shark, ask the vendor to let you smell it, if you get even the faintest whiff of ammonia...pass.
"The odds of my being correct on any given issue are inversely proportionate to the proximity of my wife" BubbaGourmet