If Sharks are immune to all known diseases, plus they are predators, not prey, so what kills?

It is better to ask who kills the sharks...Humans ... . (With pollution , fishing etc. ).

People, dolphins, porpoise, killer whales, old age.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.