Great whites hang out in 'shark cafe'
The ocean's most feared predators hang out together at a deep sea watering hole between Mexico and Hawaii known as the 'White Shark Café', according to a new study.
No animals inspire more fascination and excitement than the great white shark, but scientists admit to knowing precious little about the endangered species.
Like other open water sharks prized for their meat, they are threatened with extinction.
The new study published in the journal Proceedings of the Royal Society B identifies a distinct population and a major new genetic grouping of the great white in the eastern Pacific, only the third such "clade" ever found.
The other two concentrations of Carcharodon carcharias are off the coast of South Africa, and in the waters between Australia and New Zealand.
It had long been assumed shark species at the top of the ocean food chain that roam the high seas looking for food and mates did so almost randomly.
But using satellite tagging, acoustic monitoring of shark "hot spots" and genetic samples, a research team led by Professor Barbara Block of Stanford University found to their surprise that the eastern Pacific's great whites are real homebodies.
Over an eight year period, nearly 100 sharks were electronically tagged, and even more had tissue samples taken by scientists working from a ship.
Sticking to a schedule
They found that the sharks consistently migrate along the same paths and stick to a schedule.
Between August and December, the great whites, which can grow up to six metres and weigh three tonnes, stalk waters off the coast of central and northern California, feasting on seals and sea lions.
Their preferred hunting grounds in this area are known as the "red triangle", notes the study.
Starting in January, they head for Hawaii some 4000 kilometres to the west, where they are found in large numbers between April and July.
But some, especially males, loiter at a halfway point known as the "White Shark Cafe", with females coming and going for what scientists presume is a bit of shark intimacy.
The new findings will help conservation efforts, the study concludes: "The population's fidelity to predictable locations offer clear population assessment, monitoring and management options."
A third of the world's open water sharks, including the great white and hammerhead, face extinction, according to the largest ever shark survey completed earlier this year by the International Union for the Conservation of Nature (IUCN).
For decades, significant numbers of sharks including blue and mako have perished as "by-catch" in commercial tuna and swordfish operations.
More recently, the soaring value of shark meat has prompted some of these fisheries to target sharks as a lucrative sideline.
Around 100 million sharks are caught in commercial and sports fishing every year, and several species have declined by more than 80% in the past decade alone, according the International Fund for Animal Welfare (IFAW).