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| A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07667 |
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07666 |
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07668 |
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Guadalupe Island has long had a reputation for huge white sharks. For years, fishermen have claimed to have had white sharks steal their yellowfin tuna just as the tuna is reeled in to the boat. On past diving trips we have talked with the local Mexican fishermen, who work the island year round; one told us that in the winter, when elephant seals crowd the bolder beaches at the north end of the island, you can walk across water on the backs of the sharks. The only people who meet Guadalupe Island's white sharks -- in open water -- are those who choose to dive Guadalupe Island for pleasure or out of necessity. Mexican hookah divers work the island for lobsters and abalone, and have reported to us that they commonly see white sharks. White sharks have visited divers on some of our past spearfishing and scuba diving trips at the island, making what appear to be inquisitive passes. Tragically, two freediving spearfishermen have been attacked during the 80's while hunting for tuna at Guadalupe Island, one fatally.
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| A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07678 |
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07672 |
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07708 |
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Several attempts to attract and view great white sharks at Guadalupe Island were made in the 80's and early 90's, with occasional but modest success. In the late 90's, however, reports of sightings of white sharks at Guadalupe Island by fishermen and visiting boaters grew, especially during the late summer and fall months when tuna are found in abundance at the island. It is not clear whether the increase in sightings was the result of selection bias (i.e., more boats at the island led to greater likelihood of sightings) or a true trend in the distribution or activities of the sharks. Renewed attempts to attract and observe white sharks at the island met with considerable success, to the point that by 2002 several commercial tour companies were bringing divers to the island to view the sharks, not to mention a number of private individuals and documentary film productions seeking out the sharks there as well.
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A great white shark swims just below the rippled ocean surface of Isla Guadalupe, far offshore of the Pacific Coast of Baja California, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07721 |
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The great white shark (Carcharodon carcharias) occurs naturally in all temperate marine waters. Usually between 9 and 12 feet long (3-4m), it can grow to 20 feet (6.5m) and weigh over two tons. The great white sharks depicted in these photos were encountered at Guadalupe Island, Mexico, although recent scientific evidence suggests that the Isla Guadalupe white sharks roam north through California waters and, perhaps, as far west as the Hawaiian Islands. Great white sharks are predators, the most feared in the world. They begin life feeding on fishes, small rays and sharks, switching as they grow in size to fat-rich blubbery marine mammals such as seals, sea lions and elephant seals. Much contemporary scientific study focuses on the shark -- pinniped relationship, however the importance of this interaction may be overstated simply because the study of white sharks near land-based pinniped rookeries is considerably easier than the study of other white shark predation modes. Known for their fearsome sudden attacks, great white sharks typically surprise their prey by rushing from below and grasping the victim with a powerful, large bite. If the bite is not fatal, the prey is usually left to weaken or die through blood loss (exsanguination), at which time the white shark returns and consumes its prey.
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| A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07705 |
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07723 |
A great white shark bearing a white plastic researcher's identification ID tag near its dorsal fin swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07739 |
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Great white sharks are found throughout California and northern Baja, although they are not common. In fact, they are a protected species in California. Scientific estimates suggest there are a few hundred adult white sharks roaming the state's coastal waters. Areas in central California where white shark feeding activities frequently occur include the Farallon Islands, Ano Nuevo Reserve (site of a large elephant seal population), the Northern Channel Islands and the Marin headlands. Evidence exists suggesting that gravid (pregnant) female white sharks travel to southern California to give birth -- it may be that these waters offer young white sharks better odds of survival. As the sharks grow their metabolism changes, biasing their dietary requirements toward calorie-rich fatty prey, causing them to travel to areas where they can feed upon marine mammals. Guadalupe Island is one such place!
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| A great white shark lunges to chomp a piece of bait hanging amid the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07703 |
A great white shark lunges to chomp a piece of bait hanging amid the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07682 |
A great white shark lunges to chomp a piece of bait hanging amid the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and tuna, Carcharodon carcharias, Guadalupe Island (Isla Guadalupe), Image 07680 |
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Great white sharks, like other lamnid sharks such as the mako, are capable of regional endothermy. In other words, they are capable of maintaining an elevated body temperature in temperate (i.e., cold) waters, particularly in stomach and muscle tissue. The implications of this physiology upon the white shark's predation potential are significant. Due to its high metabolism and its oxygen-rich, relatively warm blood, the great white shark is capable of sustaining highly energetic activity and pursuing fast-moving prey (including open ocean fishes such as tunas and billfish) in an aggressive manner in temperate waters, all of which enables it to pursue and efficiently digest fat- and calorie-rich prey unattainable by other sharks.
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