What is the Great White Shark Cafe?


Scientists were perplexed when tracking found white sharks going to a place about halfway between California and Hawaii. It’s the ocean equivalent of a desert — no mountains, no valleys, no food, just an aquatic wasteland. Yet the sharks were showing up. Researchers called it the Shark Cafe.

At first they thought that if the cafe had nothing to do with food, it must be about reproduction. “Adult males and females were showing up, so that would sound like sex,” Block says. “But then young ones showed up, too, which makes everybody wonder what’s going on.”

–Little shark helps pierce Great White mystery. USA Today. 2007.

The White Shark Café is a remote mid-Pacific Ocean area noted as a winter and spring habitat of otherwise coastal great white sharks.

Location. Is it for breeding, or does their prey breed/feed there?

The area, halfway between Baja California and Hawaii, received its unofficial name in 2002 from researchers at the Monterey Bay Aquarium Research Institute who were studying the great white shark species using satellite tracking tags.

Although the area had not previously been suspected as a shark habitat, when mapping the satellite tracking data, researchers discovered that members of the species frequently travel to and loiter in the area. The reasons for this behavior have not yet been identified. The area has very little food for the animals; researchers describe it as the shark equivalent of a desert.[1] Since both male and female great whites have been tracked there, one early hypothesis was that mating occurred there. Continued studies have revealed that juvenile sharks also travel to the area, suggesting the trip serves some other purpose.

The sharks tracked to the area came from diverse rookeries along the North American coast. They typically took up to 100 days to arrive, traveling around 1m/s, during which they make periodic dives as deep as 3,000 feet. While at the Cafe, they will dive to depths of 1,000 feet as often as once every ten minutes. The purpose of the dives, either along the journey or in the Cafe area, is unknown.

By 2006, researchers had observed consistent migration and other behavior. Tracking data indicates that white sharks will leave feeding grounds near the coast in winter, travel to the Cafe, and some may even summer near Hawaii. But many linger in the “desert” where food is assumed to be scarce, often for months, before returning to the coast in time for the elephant seal breeding season (a favorite prey). Researchers hope that tracking other species such as tuna may lead to an explanation based on a mobile food source.

Sources

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