SANTA BARBARA, Calif. - The glassy-gray sea ripples with the movement beneath. Then, a fin, about the height of a playing card, breaks the surface, slicing through the water from just beyond the surf line, a glimpse of a tail tip visible a few feet behind.
The dark shape just feet beneath the murky water resolves itself quickly from the bow of a boat. On the iPhone screen where Patrick Rex, a California State University at Long Beach graduate student, has been tracking it by drone, the young great white appears like a cartoon cutout, a wide span of pectoral fins, a broad head and narrowing nose, a large, swishing tail.
It is within feet of a teenage lifeguard on a paddle board, unaware of what's below.
"You guys looking for sharks?" the surf-camp volunteer calls out, steering his stand-up board toward Rex's Boston Whaler. He is looking for them too, an early-warning patrol meant to alert the dozens of kids on the beach about 20 yards away.
"There was a six-footer just inside your board and the beach," said Chris Lowe, the veteran scientist who runs the Shark Lab at California State University at Long Beach. "It's about six yards off your port bow now."
A slow turn and the lifeguard calmly heads toward shore: Another great white shark has come too close to the rollicking campers nearby. He delivers the warning more than a dozen times a day. "Thanks," he calls coolly over his shoulder.
California, blessed and cursed by the extremes of its place at the continent's edge and the shore of the world's largest ocean, is learning with trepidation to live in harmony with "the man in the gray suit." It is a nickname that surfers have applied to great white sharks over the years, animals in their element, going about their business day.
If wildfires, earthquakes, mudslides and drought were not concerning enough, the geographic range of young great whites has expanded north along the California coast by hundreds of miles, bringing the quintessential summer-blockbuster predators within feet of surfers and swimmers from the Mexican border to beaches just south of San Francisco.
These are juvenile great whites, most just a couple years old and seven to eight feet long. Unlike their large and often cannibalistic elders who more commonly live miles offshore, and often attack people by accident, the young ones have shown no interest in adding humans to their developing diets.
But their numbers are growing.
At a thriving nursery for great whites just a few miles east of this weekend refuge of a city on the border of Central and Southern California, two days with Lowe and his team revealed more than 15 great whites, some cruising no more than four feet from the beach. Many had been tagged previously by Lowe, who the year before along the same mile-long stretch tagged 35 great whites. There were, he said, undoubtedly more today.
But the great white phenomenon here is novel mostly because of the far larger geographic coastal range where juveniles are now learning to hunt before heading offshore to the cold-water island groups that have hosted the big ones for centuries.
The wider distribution of great white nurseries is the result of successful decades-old conservation efforts and a warming coastal Pacific Ocean, which scientists say has opened a near-tropical water highway for the temperature-sensitive juveniles to comfortably ride much farther north than ever before.
The trend prompted the state legislature to act three years ago, approving a $3.75 million great white monitoring program. The money is a response to the new questions being raised by the animals and to the additional public safety risks more sharks might pose.
Late last month, a swimmer was bitten just south of San Francisco by a juvenile great white, the farthest north Lowe said he had ever heard of such an attack happening.
A few days later, off the island of Catalina in Southern California, a shark bumped a Boy Scout's kayak and bit into his hand. Those bump-and-run encounters, scientists say, may be more of a "nothing to see here, move it along now" signal from sharks rather than an intentional attack. But the last shark-bite fatality in the state was last year. According to state Department of Fish and Wildlife statistics, there have been 197 shark attacks and other types of encounters off the coast since the 1950s, including 14 fatal ones. Those numbers have grown each decade since the 1960s, peaking in the 2010s with 55 attacks.
"White sharks right now are beneficiaries of climate change," Lowe said. "But there are many questions about what is happening and why it is happening in these places. And as the teenage population of the white shark continues to grow, what and where are they going to eat?"
Warming waters, or shark population boom
The mysteries surrounding California's great white population have grown along with the geographic scope of its nurseries.
But sharks are elusive, as a few days with Lowe's team revealed, and hard to count. Shark scientists working in labs from San Diego to Monterey Bay debate if the shark population is growing or if the "distribution" of its juvenile habitats is just giving the impression of a booming shark renaissance.
Put simply, scientists want to know: Are more whites sharks in these waters? Or are these white sharks just in more places along the coast because of the warming waters associated with climate change?
The tentative answer, according to Lowe and several recent papers on the California white shark population, is yes and yes. Both phenomena are probably true.
The seminal event that prompted these new questions began in 2014. The Pacific Ocean off the U.S. West Coast has not been the same since, including the behavior of its rich variety of large mammals, diverse shark populations, and an array of other sea life.
An eastern Pacific heat wave, nicknamed the blob, shuffled the warm and cold currents that run along the California coast. The following year a periodic, if rare, weather event known as "El Niño," when warm currents surge north from the southern Pacific, reached California and exacerbated the effects of the lingering warm-water blob.
The primary consequence was that for the first time subtropical water from northerly currents from Mexico made its way around Point Conception along this country's northern coast. The outcropping - effectively the geographic gateway to Central California - had historically served as the barrier between warm southern currents and far chillier northern waters.
Suddenly, no more barrier.
Species of shellfish, anemone, commercial fish and sharks commonly native to deep Southern California and Baja were showing up in Monterey Bay - and even areas north of San Francisco. Food supplies - for migrating whales, elephant seals and sea lions, for young great whites - shifted routes and drew the large animals with them, sometimes toward shore and sometimes farther out to sea.
Salvador Jorgensen, a senior research scientist at the Monterey Bay Aquarium, said juvenile great whites were hardly seen off the Central and Northern California coasts before 2014. Now they are nearly as common as the group that hangs out in the warm waters here east of Santa Barbara off a sandy beach where, on most days, you can see the Point Conception headlands in the western distance.
"If you just look there in Monterey Bay, you would say, wow, this population is just massively increasing," Jorgensen said. "But when we took a step back and looked at what the drivers are, why these sharks are up here, we realize that there's just been this massive shift in the northern boundary of warm water along California."