海角大神

Every winter, large white sharks travel for a month to a spot in the Pacific Ocean, halfway between the West Coast and Hawaii, that scientists have named "White Shark Cafe." What they do there for several months, nobody knows.

Though scientists suspect that these sharks 鈥� which spend part of the year near the coastal islands of California 鈥� forage and mate when they migrate to the cafe, biologist Sal Jorgensen, a research scientist at the Monterey Bay Aquarium in California, wants to find out for sure.

鈥淚 want to know what they鈥檙e doing at this mysterious place,鈥� he says in . It鈥檚 possible that the sharks eat at the cafe, but unlikely: the patch, which scientists call an 鈥渙cean desert,鈥� has little animal or plant life. More likely, the sharks spend the time mating, say scientists.

In order to follow these largest known predatory fish to the middle of the Pacific and see for certain, Dr. Jorgensen enlisted the help of engineers at the Monterey Bay Aquarium Research Institute, who have built what might be the world's most durable video camera. It attaches to a white shark鈥檚 dorsal fin so that it can travel with the fish for months through the harsh ocean environment before releasing itself into the ocean and sending a satellite signal to scientists on shore who have to fetch it to collect its footage.

鈥淚t is really sort of like like a mission to Mars,鈥� says Jorgensen, 鈥渂ecause you have all these little systems that have to work just right.鈥�

Besides being small and easy to attach to a shark鈥檚 fin, the camera has to be durable enough to stay on the shark for up to nine months and be able to measure depth, light, temperature, the shark鈥檚 travel speed, and other factors.

鈥淚t鈥檚 a lot like a Fitbit,鈥� says Thom Maughan, a software engineer at the research institute who was tasked with building the camera. The device must withstand the pressure and darkness of the ocean, with a battery that can power 10 hours of video recording, along with internal data processing and storage systems. It also has to programmable so that it can collect video only when a shark engages in the most mysterious behavior Jorgensen has ever seen.

鈥淭he males are swimming up and down in the water column, sometimes 150 times a day at the cafe,鈥� adds Jorgensen. 鈥淚t鈥檚 this crazy behavior that I鈥檝e never seen anywhere else that white sharks go.鈥�

The camera will dive with the sharks and travel with them on their migration from the California coast, where they spend half a year feeding on sea lions and seals, into the cafe and back. It was only in 2002 that scientists for the first time tagged these sharks and learned where they go for the rest of the year after spending a few months near California. That鈥檚 when they found out about their congregation in the ocean desert, and that for half a year starting in December, where they likely feast on humpback whale calves or placentas.

The shark cam has been in testing this year, with the first shark-recorded footage released Tuesday by the aquarium, from a test run with sharks tagged in the Farallon Islands off the coast of San Francisco and off the coast of South Africa.

The real test of the technology will come in December or January, says the aquarium, when most white sharks will leave the California coast for the deep Pacific. Scientists will travel to a white shark hotspot, such as the Farallon Islands, and lure the fish close to the boat with food in order to quickly clip the camera to their dorsal fins.

Once their research is done, says Jorgensen, the technology will be made freely available to other scientists.