Every winter and spring, white sharks swim off the coast of California, congregating in a large, remote area the size of Colorado, the reasons for which remain unclear to scientists.
White Shark Café is the name of a mysterious gathering spot for white sharks (Carcharodon carcharias) located in the Pacific Ocean, between Baja California and Hawaii. These sharks embark on a month-long journey from their usual habitat off California to reach the Café. This area has long been regarded as an “ocean desert” with very little life, raising questions about its role in the lives of white sharks.
White Shark Café is located between Baja California and Hawaii in the eastern Pacific. (Photo: Stocktrek Images).
Barbara Block, a professor of marine science at the Hopkins Marine Station of Stanford University, coined the term “White Shark Café” while researching the migratory patterns of North Pacific white sharks using electronic tags. Between 1999 and 2000, Block and her colleagues tagged six sharks off the coast of California and monitored their movements for six months.
Four of the sharks swam southwest toward Hawaii and remained in the vast open ocean area the size of Colorado throughout the winter and spring, revealing for the first time that North Pacific white sharks spend significant time offshore. The data also indicated that the sharks dived unusually deep, reaching depths of 450 meters below the surface at this location, leaving scientists puzzled.
In the years that followed, the research team discovered that this was not a group of adventurous white sharks migrating offshore; their numbers were instead quite large, further complicating this mystery. The California coastline provides white sharks with a rich food supply, including elephant seals and various other marine mammals, so scientists could not understand why the sharks would move to such an empty expanse of the Pacific.
In 2018, Block’s research team tracked the white sharks to their gathering spot to better understand why they chose the Café. They equipped 20 sharks with satellite signal tags programmed to detach after a set period, later recovering 10 tags containing information about the sharks’ movements and deep diving behavior. They also collected data on environmental conditions and marine life at the Café.
Instead of resembling an underwater desert, the research team discovered that this is an ocean oasis. Thick layers of phytoplankton and abundant marine animal populations indicate that the Café is much more vibrant and fertile than scientists had previously assumed, confirming that white sharks gather there each year due to the food supply. The reason why sharks actively seek out this food source instead of remaining in their usual habitats remains unclear.
“We found a high diversity of deep-sea fish and squid (over 100 species), combined with observations from remotely operated vehicles (ROVs) and DNA sequencing, proving that this is a viable food source to support large marine species like sharks and tuna,” Block stated.
The diving patterns of the sharks resemble the daily cycles of migratory animals moving up and down the water column, revealing that the sharks are following their food. However, the diving behavior also raises questions about mating behaviors that the research team is trying to understand.
Male sharks increased their diving activity in April, reaching up to 140 dives per day, while the habits of female sharks remained unchanged. Researchers are still puzzled by what this means, but some experts suggest that male sharks may dive deeper to increase their chances of mating.
