The first day was interesting because, even with no bait, we encountered nine different great whites, checking out the cages – one of them, a 4.5-metre shark named Shredder, has been spotted at Guadalupe Island every year for seven years. He introduced himself to the boat seven years ago by biting off the anchor rope. While the crew was looking over the bow at the 1.5 metres of rope he left, he breached and took all 1.5 metres with him. He has since learned to interact better with humans.
I have to admit that being in a cage made of 2.5-centimetre square aluminium pipes, knowing that three-tonne great whites with jaws strong enough to crush it like a bunch of grapes were swimming around outside, did not make me feel very secure. Fortunately, these sharks had plenty to eat with a resident fur and elephant seal colony providing a major source of food. In fact, an intrepid fur seal swam out to the boat and tormented the great whites for well over a half hour. It was amazing to watch. I was on the boat, but could see the action because of the almost transparent water: the seal was a clear victor.
One disconcerting thing about the great whites was that two of the largest males, Shredder and Harvey, would cruise by the cage, so close that their pectoral fins sometimes bumped the vertical bars of the cage as they passed slowly by. They would make direct eye contact with each of us in the cage, holding that gaze a moment and then moving on to the next person. I could not help wondering what these two might be thinking…
Some of the sharks possessed a flawless beauty and some had impressive scars. Chica, a large female, had sustained a severe injury to her tail with the top third bending down at a 90-degree angle. Shredder had big chunks missing down the back of his dorsal fin and scars everywhere. Whoever said that sharks are cautious has never met Shredder!
Guadalupe Island has been declared a protected biosphere and there is ongoing research to track and monitor great white sharks by identifying and naming them. In seven years, this project has identified 96 different sharks. Some sharks have been coming back year after year like Shredder, Lucy, Chica, Skid and Harvey.
Research has revealed an extraordinary range of complex behaviours, more on par with that of large terrestrial social carnivores, such as wolves and lions. The white shark is an active, nomadic, highly maneuverable and agile social animal that shows a wide variety of sophisticated interactions with its peers and other marine organisms and humans. White shark physiology is also unique in that it’s essentially a warm-blood fish, maintaining a constant high body temperature even in cold water. This allows the predator a cosmopolitan diet and the ability to travel great distances and occupy many marine habitats, all of which have contributed to an evolutionary advantage over many of its aquatic marine rivals. Though white sharks are often sighted swimming solitary, they are, in fact, very social and tend to travel in small aggregate groups of associated individuals. Where there’s one, there’s more. The formation of social structure, a pecking-order if you will, within the species appears to be based not only on size but, perhaps more importantly, individual aggression level. When white sharks are present in numbers, there appears to be some degree of sexual segregation and age class discrimination. Males tend to hang out with others males of roughly the same size, which suggests relative age. Same goes for the females, though it is not uncommon to see both sexes present at micro-feeding sites such as rocky pinnacles along tuna migratory routes or pinniped colonies. As to what rituals may take place during mating competition, all bets are off.
Knowledge of the reproductive life cycle of white sharks is limited, due to the inaccessibility of the species. Adult white sharks are so large and relatively uncommon that they are not captured frequently anywhere by any method. Mating habits such as pre-copulatory behaviour, and actual copulation has never been witnessed, nor has a gravid white shark giving birth ever been recorded! We do know that males reach sexual maturity at around 3.5-4.1m at an age of 9 or ten years, with females larger at between 4-5m at an age of 12-14 years. There are few records of pregnant females and sparse data on litter size, with approximately 2 to ten foetuses being born per reproductive cycle. The pups are large at birth ranging from 1.1-1.6m. During development within the uterus, embryos and foetuses are oophagous, eating large numbers of nutritive eggs produced by the mother’s ovary. The gestation period is not known for certain but may be 12 months or more and gestations take place at two to three year intervals. Free swimming neonate white sharks are occasionally sighted in warm temperate coastal waters, with birth possibly occurring during spring and summer where subsurface water temperatures are at their peak.
White sharks engage in not only short-term and long-term coastal travel circuits but now appear to make trans oceanic migrations. Satellite telemetry, remote sensing and genetic studies indicate that these sharks are highly migratory, crossing entire ocean basins. In the eastern north Pacific, along the west coast of North America, they travel annually between Mexico and the Hawaiian Islands.
The white shark is the largest carnivorous fish. It is an apical “super-predator” with a broad prey spectrum. They prefer marine vertebrates but will also consume larger invertebrates such as cephalopods, gastropods, and crustaceans. Bony fish, sharks, skates, rays and marine mammals are their chief prey, but they also take marine birds and reptiles. They will scavenge on fisheries discards, dead marine mammal carcasses such as whales and fishes caught in various fishing gear. Larger white sharks tend to consume larger prey. However, white sharks are highly opportunistic feeders and efficient predators, capable of chasing and capturing fast moving prey such as mako sharks, tuna, swordfish, dolphins and eared seals. White sharks occasionally attack people, but rarely consume them; the low frequency of attacks on humans compared to the abundance of divers, swimmers and surfers where they occur as well as the nature of most attacks, suggest that the white shark attacks on people are primarily non-predatory in motivation.
THE DOs & DON’Ts
White sharks are, like most sharks, often just out of sight, watching you, and it’s never the shark you can see that you need to worry about. When looking straight down from the surface, you could be looking right at one and, because of their incredible camouflage skills, you wouldn’t see it unless you have a trained eye or great luck; but from the side or head-on perspective, there is no missing them. If you’re patient you can get great shots of these silent hunters. White sharks have a natural instinct to chase that which retreats from them. So, as they approach, stay still, take the photo and stay out of reach to avoid triggering that reaction. Some easy rules to remember include being patient, never getting out of the cage to look for them, letting them come to you and never trying to touch them. Follow these and you’ll get top-notch photos.
Because they are so curious, they will come right up to you and check you out, which is when you snap away. A good shark diving operation will be chumming with the shark’s natural prey, which will bring them close. Once they get there and see you floating like a tea bag in the deep blue ocean, they will often stick around and give you a good show.
The best action happens near the surface, which is also where the best light is! I like to use a strobe for fill, set very low, to bring out some more colour but the best shots are often taken with daylight. On a sunny day, you can shoot at a low ISO and without strobes.
As for camera equipment, I would suggest, for the pros, a good SLR with which you can shoot fully manual or automatic. One key feature to have is a focus lock: the shark is often moving slowly, in a circular or back-and forth pattern, but once in a while it snaps its massive tail and moves extremely fast. A focus lock will allow you to get a good, clear shot and prevent your camera from constantly adjusting focus points. Olympus makes great SLRs with plenty of seals to keep moisture out, like the E3 or the E-620. I shoot a variety of SLRs and protect them with Aquatica housings. A housing should never be more complicated than the camera itself, with all the functions of the camera still available including the focus lock.
For the novice, an Olympus Stylus 8000 is a great starter: it is light, compact, point-and-shoot and waterproof, so no housing is required. Otherwise, Sealife makes amazing underwater pointand- shoot cameras for very affordable prices as well.
For video, I recommend a Gates HF-S11 housing, which fits a variety of Canon HD camcorders for amateur videographers. They are great lightweight, easy-to-use systems with amazing results. If you’re a pro, you can’t go wrong with a Gates HPX 3700 housing for the Panasonic Aj-HPX2700/3700/3000 cameras. These cameras can truly achieve broadcast quality.
The great white is one of the most incredible creatures on this planet and deserves to be protected and respected. The moment you see one for the first time, you will fall in love. Be safe and may the sharks be with you.
IN A NUTSHELL
Scientific Name: Carcharodon carcharias
Weight: Up to 1,900 kg
Life Expectancy: 100 years
Conservation Status: IUCN Vulnerable
Size: 3.5 to 6+ m, The female is generally larger than the male
Diet: In general, juveniles feed on fish, while adults feed primarily on larger vertebrate prey
Habitat: Very shallow water, inshore to open ocean, and oceanic islands from the surface to 1,300 metres
Taken from Asian Diver Issue 02/2010