I'd say that fisherman are the true Apex Predators of the ocean, but agree that it's widely held view that sharks are. On the topic of predator versus scavenger, different sharks feed in different ways. Hammerhead sharks are known for eating stingrays; bull sharks eat other sharks; and smooth dogfish eat crabs and lobsters. Tiger sharks have been called the "garbage cans of the sea" because they feed opportunistically on both live food and carrion. Prey includes bony fishes, other sharks, marine mammals, seabirds, and invertebrates.
The Port Jackson shark, has two types of teeth. Front teeth are pointed for grasping and back teeth are flat and molarlike for crushing bottom food. Another mechanism some sharks use for collecting food is filter feeding, which is really just scavaging open water. The basking shark and the megamouth shark strain enormous quantities of plankton from the water on gill rakers. Whale sharks also filter feed, but instead of using gill rakers, they strain plankton through a spongy tissue.
But most of the world still holds the vision of the movie "JAWS!" and would firmly place them into the predator category. Diver's on the other hand, know that they are just a bunch curious scaredie cats. Yell at them under water and many are spooked and run.