Saturday, February 12, 2011

Great White Shark: San Diego sighting adds one more juvenile to population

This past Thursday, in San Diego, California, a 5-foot juvenile great white shark was reported by two scuba divers at around 500 yards off shore of La Jolla Cove in about 30 feet of water. Lifeguards briefly closed the beach while they cruised the area but soon reopened the beach, issuing a precaution to swimmers and leaving it at that. The local press reported the sighting without any overwrought hysteria and moved on to their next sound bite.

Chock up one for common sense.

Frankly, it does my heart good to hear of these sightings. With each juvenile seen, we know there is one more shark to add to the white shark's precarious population; one more shark that can, in 10 years, reproduce and, as Matt Hooper said, "make little sharks." Juvenile white sharks do not pose a substantial threat to humans as they are fixated on fish as menu items. It won't be until they reach maturity that they graduate to pennipeds (seals and sea lions) and the possibility of a surfer or swimmer being mistaken for a seal could occur, and has occurred.

But why off of warm Southern California? Juveniles have been sighted from Malibu to San Diego. There are deep canyons that run along the coastline in which juvenile white sharks can comfortably cruise, feeding on fish, while adults have generally taken up their migration patterns that often bring them to areas of seal or sea lion concentrations, like the Farallon Islands off San Francisco and Isla Guadalupe far off the Baja coast.

A recent report from the Shark Research Committee, a California non-profit headed by well-known shark behaviorist Ralph Collier, cited 7 unprovoked shark attacks along the Pacific Coast in 2010; 5 in California waters and 2 off the Oregon coast. Only one attack produced a fatality. Of interest were the activities the people were involved in at the time of the incidents: 3 surfing, 2 kayaking, 1 paddle-boarding, and 1 boogie-boarding. All surface activities, all included an elongated shape with limbs or paddles in the water. When you add in the right conditions of low visibility or other possible attractants like heavy splashing or nearby pinnipeds, all lend themselves to the classic scenario of mistaken identity as the white shark executes its typical single-bite ambush technique which it uses on an unsuspecting seal or sea lion (although not definitively confirmed, the white shark was suspected in all seven incidents). The attacks also took place in the late summer/early fall. This is when many adult great whites are on the move, returning from their mid-Pacific migration, back to their coastal hangouts.

Given the image that is generally served up by the media, I don't expect the general public to rejoice with every sighting of a great white shark along the California coast. But it's good to know that the circle of life is still taking place for these threatened ocean predators who play such an important role in balancing the marine ecosystem. Hopefully, the juvenile white shark seen off La Jolla Cove will not encounter poachers and live to carry on the species.

Read about the white shark sighting in San Diego.
Read about the Shark Research Committee

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