Great White Sharks
Great White Sharks—We’re Not on the Menu
If you have visited our beaches recently or watched the local news, you have probably heard about great white shark sightings. There seem to be more sightings, mostly of juvenile (young) sharks, and in some cases, there have been shark-human interactions. Are these massive Chondrichthyans (cartilaginous fish) suddenly taking over the Monterey Bay?
The truth is, they have always been here. The productive waters of the Monterey Bay are an abundant food resource for many sea creatures—whales, seals, and sharks alike. White sharks feed on marine mammals with up to 50% body fat, such as elephant seals or sea lions. They must consume animals rich in fat in order to supply their enormous livers, which may comprise one-sixth of their body weight. Unlike other fish, sharks lack a swim bladder, so a large oily liver keeps them afloat.
Contrary to their reputation, great white sharks are highly selective in their diet. Though technically cold-blooded, these predators maintain an internal body temperature above that of the surrounding seawater. This means high muscle performance for hunting, but also a very high energetic cost. They are known to reject animals like sea otters after the initial bite, likely because otters have thick fur instead of blubber to keep warm. If a shark was to actually consume a human (which has never before been documented), it would have immense trouble with digestion due to our high ratio of bone to muscle and fat. Human victims are rarely struck more than once. Furthermore, interactions like these are seldom predatory, meaning the shark does not launch itself out of the water with the victim in its jaws as it would with a seal.
Although some researchers suggest that the California white shark population has been growing since its official protection in 1993, others state that there is no empirical evidence of growth. Instead, there may be a northward expansion of juvenile white sharks’ feeding habitat (usually Mexico and Southern California), which can occur during years when the water in Monterey Bay is warmer.
What about the seeming increase in encounters? Numerically, the average number of attacks per year in California has increased from 0.9 to 1.4 since the 1950s. However, the number of visitors to the beach has also risen drastically, and more are visiting each passing year. The Monterey Bay Aquarium website states that your chances of being attacked by a white shark in California have actually decreased by 90% in the last 50 years. In addition, the California sea lion population has recovered from a few thousand in the 1950s to 300,000-400,000 today. With so much of their preferred prey available, great white sharks are even less likely to interact with humans in a predatory manner.
If you still have not breathed a sigh of relief, check out these statistics and this video and consider this:
The majority of the white sharks in the bay are juveniles, attracted to small prey like rays and the safety of the shallows.
Far more white sharks are killed by humans than vice versa, specifically for shark fin soup. It’s estimated that 100 million sharks (including white sharks) are killed by humans each year, while the total number of shark-related fatalities in the US since 1959 is 26.
These animals deserve our respect, not our fear. They play an important role in the ocean food chain and need our protection.