Oy vey... I said it when I first saw the trailer and I will say it again: Why on earth did this story NEED to be told with *FISH*?! It would've been fine if the writers/designers/animators actually took advantage of the fact that the story is told with fish, but sadly no... this is really a story about people in fish suits living in a urban center that happens to be covered with coral.
Our hero: Oscar... perhaps better described as Will Smith in a fish suit.
Our story: Small time "loser" Oscar takes credit for the death of the local mobster's son. Everyone believes that Oscar is a hero, making the city's streets safer for everyone... when the mob boss finds this out he wants his son's killer dead.
Oh, and add fish...
I sat in the theatre waiting for this movie to get funny... (it didn't)... waiting for my annoyance over the fact that all the fish seemed to have necks, knees, elbows, fingers... (nope, still bothers me)... waiting desperately to actually start caring about the characters... (nope, sorry).
Actually that's not quite true. The only character I had a mild interest in was Lenny. His plight--as the resident vegetarian shark who just wants to be accepted--was vaguely interesting. Lenny was a good, if misundestood, kind of guy.
Oscar was just Will Smith in a fish suit. Sorry Will.
Athena's advice to you on "Shark Tale": skip it.