So, putting all the pieces together, it seems that divers who are attacked by White Sharks are visually mistaken for sea lions and then spat out because they're just too damn skinny to be a worthwhile meal. And speaking of fat, there is good evidence that blubber scavenged from whale carcasses is a major source of energy-rich food for White Sharks. But its an awfully big ocean and whale carcasses must be, at best, gigantic but rare windfalls. All available evidence suggests that the Great White Shark is a capable and efficient predator in its own right. Optimal foraging strategy is one of the hottest areas of theoretical ecology, and one of the hardest to demonstrate in the wild.
Behavioral ecologists use the term strategy in a different way from most people.
Strategies may be defined as a suite of inherited traits, molded by natural selection, which allow an organism to solve ecological challenges. It is certainly tempting to interpret the White Shark's strategy for feeding on pinnipeds as very cold and calculating, resulting in greater reproductive output. In truth, almost the exact opposite occurs. White sharks which do NOT behave in ways that minimize energy expenditure or risk are selected against, because energy that went into inefficient predation or healing wounds was no longer available to increase reproductive potential. Unless one defines strategy with great care, it is easy to get tangled in mental knots when thinking about why animals do what they do.