Are white sharks doing something different this year? Or are we?

Dec 8, 2015

 


If you want to see great white sharks in the Bay Area, the best place to go is the Farallon Islands. It’s about a two hour boat ride from the Berkeley Marina. 27 miles offshore.

The Farallones are part of the Red Triangle, an infamous stretch of coastline from Año Nuevo to Bodega Bay where sharks congregate. Here, they feast on crowds of elephant seals and California sea lions.

I’m here with David McGuire. He’s the director of Shark Stewards, a shark advocacy group. These boat tours are a way for shark enthusiasts to learn more about their favorite predators -- but they’re also a way to teach people about conservation efforts, like the recent statewide ban on shark fins.

Sharks get a bad rap

I was nervous about this trip. This year there has been an unusually high number of shark sightings around the Bay Area. A few months ago, a group of young white sharks were found swimming close to to the Monterey Shoreline, and a Coast Guard helicopter spotted 20 sharks swimming close to shore between Pacifica and San Francisco’s Ocean Beach. And like lots of people, most of my exposure to white sharks is through terrifying movies like Jaws. I had recently watched a unnerving video shot on Alcatraz by a tourist on her phone. You don’t see a lot of the shark, just a dorsal fin, the flick of a tail, and expanding pool of red where a seal used to be. The kid watching in the video steals the show. He’s amped.

More sharks? Or more photos of sharks?

And he has reason to be excited. White sharks uncommon - some research shows there could be fewer than 500 along our coast. Scientists are pretty sure that no one has ever recorded footage of them feeding in the Bay before. It doesn’t mean this is the first white shark to cross the golden gate — there’s evidence that they have. It’s just that no one was around to see them. But that’s starting to change.

“People are always sending me pictures of white sharks in San Francisco Bay near the Richmond Bridge,” says Dr. John McCosker, one the world’s leading white shark experts. “They are sending me pictures of white sharks right off the coast.”  

McCosker is careful to distinguish that this uptick in sightings mean. “Does that mean that there are more whites sharks off the coast?” he says. “Not sure yet," he says, "but it certainly seems that there are more white sharks being photographed off the coast.”

In the 80s, McCosker was one of the first scientists to use electronic monitoring to study white sharks. Since then, white shark research has gotten a lot more advanced, but no less adrenaline filled.

 

Technology gets more complicated

 

Taylor Chapple is a Stanford Researcher who’s been tagging white sharks out at the Farallones for the past decade. When I met him in person, he was carrying a orange, hot-dog sized tagging-device found by a fisherman earlier that morning. It’s basically a small computer that fits on the the shark’s fin like a clothespin. It has information about how deep they swim, when they accelerate, and where in the ocean they might be.

“It gives us an unprecedented view of what the animals are doing,” says Chapple. “So it's pretty amazing.”  

Some of that information is then presented to the public on Chapple’s internet app. It’s called Shark Net.

“You get to know the animals, and then you get to see what they are doing in real time,” Chapple tells me.

 

You can get to know sharks named Scargirl, Mr. Burns, Tom Johnson. You can examine their markings and find out when they last stopped by the Farallones. And there are videos, too. In one of them a shark swims through a sea of pink jellyfish. There’s no Jaws music, no dramatic baritone voice over. One of the scientists grabs the camera out of the water and wipes the lens with his fingers. It feels as close to a shark home video as I’m ever going to get. Chapple tells me this candidness is important for the conservation effort.

Turning fear into appreciation

“You don't need to scare people in order to educate them,” says Chapple. “I think if people got to experience sharks not on television — if they got to experience them first hand or the way we do — I think that will change that mindset from this fear to a real appreciation.”

This shift is not just sentimental. Chapple has the science to back it up. He recently coauthored a paper that showed while there are more documented shark attacks, the individual risk has gone down by 91 percent since 1950. If you’re a surfer, you have a one in a 17 million chance of getting bitten. The reduced risk might be because the population of white sharks is decreasing off our coastline, or chasing seals elsewhere, or that people just know when not to get in the water in places where sharks congregate.

And Chapple’s tagging research is helping to create a sort of shark census. It’s a work in progress, but his team is slowly collecting data about the true number of sharks out there, and how changing ocean conditions like warmer waters can influence where they go.

 

The El Niño effect

 

“Were white sharks behaving differently this summer?” asks shark researcher John McCosker. “I believe so. White sharks are certainly responsive to the El Nino event”

McCosker thinks this is because their food sources also have moved north with El Nino’s warming waters. Other scientists think the sharks may be attracted to plumes of warm waters that can be found close to shore. Despite the unanswered questions, scientists say studying these animals also gives us crucial insight into the well-being of our oceans

“It takes a lot of flesh to feed an apex predator of that size,” says McCosker. “That's in fact why they are so uncommon — but also why they are so critical to the environment. They at the top of the food pyramid are key players, they are keystone species”

White sharks keep the ecosystem balanced, and are barometers of the health of the entire food chain. That’s part of the reason white shark scientists study them so intensely even though the animals are rare — and why they’re so happy that the public is getting involved.

 

“I'm thrilled that there are so many more opportunities for the public at large to take photographs of natural events to send them to other museums and agencies so that we can use that information,” McCosker says.

On my boat trip to the Farallones, I didn’t see any sharks, but I clutched my camera the entire time, waiting to snap a photo or shoot a video of them to add to the growing number of images we have of them. We might not know if the population of white sharks is increasing but, but we know that our documentation of them is. Really, it’s a democratic approach to science, one that’s supplying researchers with more information on where these sharks are, and giving the public the chance to see them outside the movie theater.