Featured on Slate, marine biologists are examining the migratory patterns of a group of great white sharks. This population of great white sharks (Carcharodon carcharias), found along the coastline from Central to Baja California, disappears deep into the Pacific Ocean during the winter. The sharks swim for up to 40 days when they reach a point approximately halfway between Mexico and Hawaii. Here the sharks congregate, and this behavior is baffling scientists.
One reason why scientists are confused is because the location is nothing remarkable. This area is between 3,000–5,000 meters deep; it is also an area that doesn’t have much in the way of food supply for the predators. Nevertheless, the large group of sharks remain in the region between the months of April to July. The size of the territory is no larger than 70,000 square kilometers.
This is not the end to the odd behavior. The first sharks to reach the area tend to be females. When male great white arrive they engage in deep diving behaviors. The male sharks go through a process of diving to around 200 meters and then back up. A typical shark does this some 150 times per day. Given this happens each year, and a great white can live for up to 70 years, this is a considerable amount of repetitive behavior.
Marine biologists think either there is a food source deep in the ocean or the behavior is a ritual or sorts. To find out more, National Geographic reports that a team led by Salvador Jorgensen and Thom Maughan, (from the Monterey Bay Aquarium Research Institute) have begun tagging some of the sharks and fitting them with special low light cameras onto the dorsal fin, designed to with stand the water pressures at the lower depths of the ocean.
According to social media using marine biologist Daniela Valencia (@DanielaV13), a documentary about the mission to work out what the sharks are up to called Blue Serengeti, will be shown several times on the Discovery Channel.