"The Frankfurter Allgemeine news website reports that Knut "senselessly murdered the carp", fishing them out, playing with them and then leaving the remains."

Doh. It's a polar bear. It has a natural instinct. It is SUPPOSED to kill fish. Hand-rearing it may mess with its head, but it will not remove instinct. And nor should it. Also, anyone who thought the carp would be left alone to eat algae and remain intact is stupider than those who succumbed to "Knut-mania" int he first place. And if somebody put the carp in there to show that the polar in question was a wild animal and not some sort of vegetarian celebrity then good on them! An animal is an animal. Full stop.

I agree with you. It's in his instincts to catch fish and anything else that lives in water. Let's just hope they don't give him some seal companions.