Are the sharks and killer whales both extraterrestrial predators introduced by them to make the oceans unsafe?

This is very much the case. It is a perfect illustration of the mismatch with so many species and that of divine human sharing the habitat of earth. It is no different than the great African predators, such as the lion and the hyena. There is savagery on display and this is seen as natural because it contributes to a balance of nature, but they are not essential. Overpopulation heals itself with or without predators to cull the herds.