What is the theme in Close to Shore: The Terrifying Shark Attacks of 1916 by Michael Capuzzo?

Although knowing what we know about great whites in modern times, it is amazing to learn that as recent as 1916, the shark was not thought of as a dangerous animal. And it wasn't just the vast, uninformed public that had a grave misconception about these animals—it was the experts and experienced fishermen who claimed, at various times, that the shark was a timid, non-aggressive animal and that its jaw power was insufficient to bite through bones.