WASHINGTON – For years, humans have thought of great white sharks wandering the sea at random, only occasionally venturing close to shore.

We were wrong.

Pacific white sharks spend months near the northern and central California coast between August and February foraging among elephant seals, sea lions and other prey, according to a new study published online Tuesday in the biological research journal Proceedings of the Royal Society. The team of 10 California-based researchers determined that these sharks probably pass close to populated beaches and have been spotted as far inland as the mouth of the San Francisco Bay, east of the Golden Gate Bridge.

“It shows you how wild it is off our West Coast of North America. This is Yellowstone,” Stanford University marine sciences professor Barbara A. Block, who co-wrote the paper, said.

By tracking their movements, scientists determined that the fearsome predators make such precise, regular migrations each year between the California coast and the Hawaiian islands that they have become genetically distinct from their counterparts on the other side of the Pacific.

The fact that “a major concentration” of great whites can ignore the humans who might have crossed their path there “shows us the sharks are really minding their own business. The number of interactions with people is very small, considering,” Stanford University post-doctoral scholar Salvador Jorgensen, the paper’s lead writer, said.

The findings represent nearly a decade of work, during which scientists tagged 179 great white sharks that roam the Pacific Ocean. They lured the creatures to their boat with a carpet decoy designed to look like the silhouette of a seal, and used a lance to attach the tags with the aid of 2.3-inch titanium darts.

They used three technologies to track the sharks’ movements: satellite tags, which archive travel data by measuring the light in the sea and using astronomical math to determine where they are swimming; acoustic tags, which register a precise location when a shark comes within about 820 feet of a receiver; and mitrochondrial DNA sampling, which maps the animals’ genetic lineage through their maternal line.

While researchers set up acoustic receivers in four central California locations where they knew the sharks would congregate – Ano Nuevo Island, South Farallon Island, Point Reyes and Tomales Point – they discovered by accident that several white sharks entered the mouth of the San Francisco Bay. That is because the five great whites set off receivers established by another team, which had put them there to track migrating salmon.

Just as important, the scientists were able to determine through satellite tagging that great whites left the California coastline each winter and traveled 1,240 to 3,100 miles to the Hawaiian islands.

Researchers are conducting a census of the threatened creatures off California’s coast, because their exact numbers are unknown.

Awe-inspiring Sharks

The “Jaws” myth: The great white shark has a fearsome reputation as a predator. However, most attacks on humans are not fatal, and research finds that they appear to be motivated by curiosity, rather than a desire to feed on people.

What’s in a name: Great whites have gray upper bodies that can vary in hue depending on lighting and water color, but they get their name from their universally white underbellies.

How big: Great whites are the largest predatory fish on the planet. They grow to an average of 12 feet in length, though they can exceed 20 feet and can weigh up to 5,000 pounds.

How fast: They are torpedo-shaped swimmers with powerful tails that can propel them through the water at speeds of up to 25 miles per hour in short bursts.

How many and where: These sharks are found in all cold temperate and tropical waters. They are relatively few in number, and those numbers have declined in recent decades. They are listed as a threatened species.

Feeding machines: Highly adapted predators, great whites have mouths lined with as many as 300 serrated, triangular teeth. Narrow teeth on the bottom hold prey, while the triangular top teeth are for cutting. The Washington Post