If there is one thing about the ocean that everybody knows, it is that there are sharks out there—lots of sharks. A person need not even have had put a big toe into the sea to know this.
In many ways, this is true. Within the cartilaginous fish orders Lamniformes and Squaliformes, there are over a dozen families and altogether about 350 species. And some of these species can be abundant.
But so often the thought which accompanies the feeling “that there are lots of sharks in ‘them- thar-waters’” is that virtually all sharks are vicious man-eating terrors, just waiting to bite off a person’s big toe as soon as it enters the sea.
Divers, however, have long known this not to be the case (as evidenced by the fact that almost all divers have a full ten-count of their toes). They well know that the majority of the sharks they encounter while diving are harmless to anything much bigger than a shrimp or clam, and even the few with a full set of chompers that are capable of biting people, usually opt not to.
Furthermore, in recent times, it has become more and more apparent that it is the sharks that are in danger from the activities of people rather than the other way around.
However…
…this is not to say that there is no basis whatsoever to the idea that sharks are vicious eating machines, which will eat just about anything and everything that they can. Yes, there are a few species that are just about as mean and nasty as the tales that are told.
One of these is the tiger shark (Galeocerdo cuvier), a wide ranging species that roams the coastal areas of all tropical and subtropical seas. It occasionally wanders into the colder waters of California, known rarely from off shore Southern California, but potentially could even be farther north. Its common name was given due to the its striped pattern when young, which nicely complements its aggressive, tiger-like ways.
As a member of the notoriously feared Family Charcharinidae (often referred to as the requiem sharks) the tiger shark is a powerful, streamlined cruiser, with a full set of sharp daggers for teeth, which make it an effective hunter of other fishes, squids, turtles, crabs, dolphins. Considering that the tiger shark can grow up to at least eighteen feet in length and weigh as much as 2,000 pounds, it obviously can take on just about anything else in the sea. It is not even adverse to eating smaller sharks!
And it doesn’t even limit itself to “live-and-kicking” prey. Although it does give preference to more digestible food, it is a skilled scavenger and it will consume all sorts of strange stuff—dead animals, old shoes, old cans, spools of wire—basically anything and everything it happens to find.
A disconcerting aspect of tiger shark behavior is how readily it will enter shallow water in pursuit of food.
During the day it tends to stay offshore, but at night, which is when it prefers to hunt, it has no aversion to coming into areas only deep enough for people to wade.
Like other large sharks, the tiger shark bears live young. A female tiger shark carries the babies within her for 13 to 16 months, and she can give birth to between 35 to 60 pups ranging around 20 to 35 inches in length. These pups grow and mature quite rapidly and are able to reproduce at about age 7 to 10. As of yet, no definite tiger shark pupping areas have been identified.
In contrast, the common leopard shark (Triakis semiflasciata) has known pupping areas, such as near Catalina Island. This rather docile smaller shark is sometimes mistaken for and referred to as a tiger shark because of the similarity in blotchy patterning.
While this reproductive rate is one of the better among at least the larger sharks, so little is still known about them to know exact population figures or to make a lot of predictions.
Shark populations of most species worldwide are known to be declining due to the pressures of fishing, whether as target species or as by-catch. Hence, the International Union for Conservation of Nature and Natural Resources (IUCN) does consider the tiger shark to be at some risk (and hence classifies it as “lower risk/near threatened”).
For the most part though, at least when in California waters, the tiger shark is more of an anomaly than a threatened or threatening species. Sure, one could take a bite out of a person if it really wanted to, with so many other good tasting stuff—and maybe not so good tasting stuff as well—to choose from, for the most part, it doesn’t seem to pay that much attention to divers or swimmers.
Of course, any diver or swimmer who happens to see a tiger shark, will undoubtedly pay it very, very good attention. For even in California waters, this wide-ranging known man-eater is worthy of both its reputation and great respect.
