Every year for more than 20 years, scientists have been tagging great white sharks in the Bay Area.
And every year, those sharks migrate to a specific spot more than 1,200 miles offshore that's long been considered an oceanic desert.
Scientists believed the sharks were going there to either mate or take advantage of a food source, and they called it the White Shark Cafe.
"We've studied these sharks for nearly 20 years, and they've told us consistently that the White Shark Cafe is a really important place in the ocean — but we've never known why," Dr. Salvador Jorgensen, a senior research scientist and lead shark researcher at Monterey Bay Aquarium, said in a news release.
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On April 20, a team of scientists from Stanford University, the Monterey Bay Aquarium, the University of Delaware, NOAA's Office of Ocean Exploration and Research and the Monterey Bay Aquarium Research Institute set sail from Honolulu for the White Shark Cafe, hoping to begin unraveling the mystery in a monthlong expedition.
And they found that the cafe, which has also been referred to as the "Burning Man" for sharks, isn't a desert at all — far from it.
In a panel discussion hosted by the Aspen Institute, Stanford University marine biologist Barbara Block, who led the expedition, said they collected a "treasure trove of data," including information about oceanography in the cafe, currents and chemistry.
Scientists also found a layer of carbon, which helps support marine life, about 100 meters below the surface, Block said. Since it was so far below the surface, satellites wouldn't have been able to see it. That carbon layer helps support the sharks' prey.
Block said in the video panel that, before the expedition, scientists worked for about four months to tag about 38 white sharks.
"The dream of the voyage was the white sharks were going to show us a place we knew existed, but we had hoped we could go there," she said.
And as for finding the cafe, Block said her team just had to know about where the sharks would show up. She likened the experience to tagging and releasing 38 mountain lions in California and expecting them to show up in Colorado.
"Sure enough, they ended up in a place that's about the size of Colorado in the northeast Pacific," she said. The tags researchers attached to the sharks collected about 3,000 days of data.
And the White Shark Cafe isn't just for the white sharks: Block said her team also recorded mako, ahi and blue sharks in the cafe area.
The expedition docked in San Diego on May 19, according to a news release from the Monterey Bay Aquarium. The next step is for researchers to compile and analyze all the data they collected at the White Shark Cafe to create a detailed, three-dimensional picture of the cafe's environment. That picture would document the oceanographic conditions in the area, the prey surrounding the sharks, and tell scientists where the sharks are.
And Block believes a clearer understanding of why sharks visit the cafe will help lead to protecting the waters from commercial fishing, she told the Pacific Standard. The White Shark Cafe was mentioned in a 2016 United Nations report as a potential UNESCO World Heritage Site, a designation that would give the area protected status.