Sharks hunt using their sensory systems not their eyesight (which is pretty terrible). They’ll often hunt in river-mouths, murky water and at sunrise or sunset and will bump their prey before attacking it. To a shark, a surfer can look just like a seal from below – one of the favourite snacks of larger, temperate water shark species.
Oceanic whitetip shark with an entourage of pilot fish. The whitetip is a large pelagic shark inhabiting tropical and warm temperate seas. This aggressive but slow-moving fish dominates feeding frenzies, and is a danger to shipwreck or air crash survivors. Recent studies show steeply declining populations because its large fins are highly valued as the chief ingredient of shark fin soup...The pilot fish eats ectoparasites on, and leftovers around the host species.