When orcas and white sharks cross paths, only one can prevail as the true apex predator. New research from the Monterey Bay Aquarium published in Nature Scientific Reports details these rare, sometimes brutal encounters — and their ecological implications.
It’s a study decades in the making because observations of the two creatures interacting is a rarity.
Scot Anderson, a white shark expert and seasonal researcher for the Aquarium, still remembers one such run-in more than 20 years ago near the Farallon Islands, a short boat ride west of downtown San Francisco.
“The first time it happened was kind of shocking to everybody,” Scot says. “Before we had seen anything like that, people would ask, who’s the baddest predator?”
The first scorecard came on October 4, 1997, when orcas killed and partially ate a white shark within view of a whale-watching boat. Scot was heading out from nearby Bolinas when he heard what was happening over the radio.
The week of September 10, people from around the world are gathering in San Francisco for the Global Climate Action Summit. Convened by the State of California, the Summit brings together leaders—representing nations, states, cities, companies, investors and citizens—to celebrate climate action, and step up their ambitions to meet the targets set by the Paris Agreement. Monterey Bay Aquarium works on multiple fronts to address the ocean impacts of climate change. Here, we present several recent scientific findings on the complex ocean-climate connection.
Science powers the Aquarium’s mission to inspire ocean conservation. It’s the basis of our public education programs, our work to protect vulnerable marine species, and our efforts to address climate change and ocean acidification.
We advocate for policies—from the local to global levels—to reduce carbon emissions, end our reliance on fossil fuels, promote clean energy and mitigate the unavoidable impacts underway. And we believe those policies must be based on the best available scientific evidence.
Monterey Bay and surrounding waters are prime habitat for white sharks. The same adult white sharks visit this part California annually over decades, mostly during fall and early winter. Farther south, from Santa Barbara to Central Baja, white shark babies, or pups, typically spend their first years in warmer “nursery” waters.
What’s new and surprising, though, is that in recent years a seasonal group of younger white sharks has established itself within sight of the beaches at the north end of Monterey Bay. Is this new cohort taking up residence as a result of warming ocean conditions? And why are the sharks aggregating in one portion of the bay?
This spring, a diverse team of ocean scientists headed to the middle of the Pacific Ocean, seeking to explore the vast and mysterious home of one of the world’s top ocean predators: the white shark.
Guided by the sharks and their need for a steady supply of food, the researchers sailed into the heart of what was once deemed an oceanic “desert.” They discovered that the open Pacific, particularly an expanse dubbed the White Shark Café, teems with abundant and unusual life forms—organisms that may help explain the fascinating behaviors of white sharks on the high seas.
“The Café is far from the desert it was thought to be,” says Aquarium research scientist Dr. Sal Jorgensen. “It is home to an abundance of life that satellite imaging is not detecting. In fact, for white sharks, it is more of an oasis.”
The White Shark Voyage team embarked from Honolulu for a month-long journey aboard the Schmidt Ocean Institute’s R/V Falkor and traveled east to waters halfway between Hawaii and Mexico.
Headed by principal scientist Dr. Barbara Block of Stanford University, the research team aboard the Falkor included marine biologists, engineers and oceanographers from Monterey Bay Aquarium, Stanford, Monterey Bay Aquarium Research Institute (MBARI), University of Delaware, NOAA, Montana State University and ocean tech innovator Saildrone.
While no one knew what they’d find, everyone hoped to gather insights about what might be driving the behaviors of white sharks, and what role this offshore habitat plays in the lives of these apex ocean predators.
What can scientists studying white sharks learn from an expert on mountain lions? As it turns out, quite a lot.
Such a collaboration is on display in new research published in the Journal of Applied Ecology. Models that estimate survival rates for top predators on land, according to the study, can also work in the ocean. The research also revealed important safeguards that can help protect white sharks while they’re young and vulnerable.
“We always learn things from adjacent fields,” says Sal, who specializes in white sharks, and who coauthored the paper along with six others. “John made his name studying mountain lions in Southern California.”
John’s past work also involved black bears in Louisiana, panthers in Florida, wolves and coyotes in Canada, and moose and their various predators in Alaska. After so much experience on land, John saw working with Sal at the aquarium as a chance to—as the saying goes—get his feet wet. Continue reading New insights to help young white sharks survive
For nearly 20 years, researchers from Monterey Bay Aquarium and Stanford University have fitted electronic tracking tags on adult white sharks each fall and winter along the California coast around San Francisco Bay. Each year, the tags documented a consistent migration by the sharks to a region more than 1,200 miles offshore—halfway to Hawaii—that’s been considered an oceanic desert. They dubbed it the White Shark Café, guessing that opportunities to feed and to mate might be the draw.
Now a team of scientists will spend a month at the Café in a month-long expedition to learn why the sharks make an epic annual migration to such a distant and seemingly uninviting location. The multi-disciplinary team is bringing an impressive complement of sophisticated oceanographic equipment, from undersea robots and submersibles to windsurfing drones that will search signs of sharks and their possible prey.
By documenting the biology, chemistry and physical conditions in the region—a swath of the Pacific Ocean the size of Colorado—the researchers hope to understand what makes the Café an annual offshore hot spot for one of the ocean’s most charismatic predators. Continue reading Voyage to the White Shark Café
For more than 30 years, the Monterey Bay Aquarium has been a key contributor to sea otter recovery in California. Aquarium researchers and policy experts have advanced scientific knowledge, promoted improved management and raised public awareness of the contributions sea otters make to healthy coastal ecosystems. A new research paper in the journal Ecography draws on three decades of Aquarium research to establish a link between sparse kelp cover along the California coast and a recent rise in sea otter mortalities from white shark bites. The finding illuminates a new challenge for everyone working toward sea otter recovery: Will sea otters be able to run the gauntlet of white sharks and expand back into their historical range without human assistance? Conservation Research staffer Athena Copenhaver explores the challenge.
Senior research biologist Teri Nicholson fans out her left hand, tapping each finger as she recites a brief list of unusual names: Jiggs, Goldie, Hailey, Milkdud . . .
They might sound as though they belong to beloved pets, but Teri is actually recalling the stranded southern sea otter pups taken in by Monterey Bay Aquarium back in 1984.
Although Teri and her colleagues didn’t know it at the time, these first four orphaned pups became foundational data points in a pioneering sea otter study that spans the lifetime of the Aquarium.
“By rescuing and rehabilitating stranded animals, we can observe symptoms and determine possible reasons the animal might have stranded,” explains Teri. “And, that means we can look for patterns in threats otters face over time.” Continue reading Sea otters’ perilous path to recovery
For over two decades, Monterey Bay Aquarium and Stanford University have partnered to study some of the world’s most mysterious ocean predators at the Tuna Research and Conservation Center (TRCC). Some of the latest work to come from the TRCC include an innovative tuna tag design, and a paper recently published in the journal Sciencedetailing the discovery of a hydraulic mechanism in tuna dorsal fins, which helps them swim with speed and precision.
In his office at Stanford University’s Hopkins Marine Station in Pacific Grove, California, Dr. Vadim Pavlov holds a pale, sleeve-like device. Its smooth lines and soft edges make it seem more like a child’s toy than a high-tech scientific product. He slips the device over a model of a dolphin dorsal fin and “swims” it around his office, mimicking a dolphin’s movements as it leaps and twists out of the water.
The device is a prototype of a new tag design intended to track top ocean predators, such as sharks and tunas, without using pins and bolts that penetrate the fin.
“Even when the dolphin leaps, the tag stays on,” Vadim says. “But, how did we do it?”
Form and function
Vadim is one of the world’s top experts in biomimetics: the science of translating natural phenomena, such as the flow of water over a dolphin’s dorsal fin, into useful technology.
For years, he’s been tackling the challenge of tagging and tracking wildlife in the open ocean. He wanted to provide “animal-friendly” tags as an alternative to the invasive bolt tags anchored into the fins of apex marine predators such as sharks, dolphins and tunas. For Vadim, that’s not just a scientific goal; it’s personal, inspired by his experience as a free diver. “I don’t like swimming with lots of gear, so I don’t think [animals] do either,” he says. “They are very sensitive to anything on their bodies.”
Traditional bolt tags, a key tool in marine animal field studies for the last half century, are kind of like an ear piercing. Researchers punch through the cartilage and collagen in the dorsal fin and attach tags that can help track the animals, or collect environmental data such as salinity, temperature, and depth.
“But over time, these bolt tags do not move with the animals,” Vadim explains. “They can alter the flow of water around the animal’s bodies, and can even cause animals to turn more in one direction over time,” he says. “The faster the animal swims, the greater the energy needed to override the drag.”
Smaller animals, such as harbor porpoises and juvenile dolphins and sharks, are especially susceptible to the pitfalls of traditional bolt tags. “There’s a conflict between the animal’s biology and the technological requirements of the tag,” says Vadim. “So my job became how to reconcile that disconnect.” Continue reading Designing an animal-friendly fin tag
The Monterey Bay Aquarium is a science-driven organization, and rigorous science underpins all of our public policy, research and education programs. Much of our research centers on marine life that visitors can also see in our exhibits – from sea otters to sharks and tunas, even our giant kelp forest. Here’s some of what we’ve learned over the past 30-plus years that is contributing to conservation of key ocean species and ecosystems.
Sea otters crack open tool-use secrets
Revolutionary female scientist Jane Goodall was the first person to discover that chimps use tools and live within complex social systems. Our team of female researchers are walking in Jane’s footsteps with their recent studies on use of tools by another mammal: the sea otter. When observing sea otters along the Monterey Peninsula, sometimes we can hear a “crack, crack, crack!” above the roar of the tide. That sound comes from sea otters using rocks and other tools to open prey items, such as crabs or bivalves, as they float on their backs. Sea otters are avid tool users, but until recently not much was known about how sea otters choose their tools, what aspects of their environments influence tool use, or whether they teach tool use to other otters. The Aquarium’s decades of research into sea otter behavior provided years of observations of sea otter foraging and tool-use behavior, including sea otter pups pounding empty fists against their chests. Could such activity be instinctual? Research Biologist Jessica Fujii has devoted much of her young career to studying the frequency and types of tools used and whether tool use can be coded in sea otter genes. Jessica is looking ahead to see how sea otters learn, teach, and eventually master tool use in the wild.
Sea otter surrogacy helps restore Elkhorn Slough
With 15 years of experience rescuing, rehabilitating, and then releasing surrogate-reared sea otters into Elkhorn Slough, an estuary near Moss Landing, California, the sea otter research team at the Aquarium began to wonder how and if their work was affecting the otter population there. Does releasing a few animals into the slough each year really make any difference? After crunching some serious numbers from the surrogacy program and the U.S. Geological Survey’s (USGS) annual sea otter census, the researchers discovered that it did. Nearly 60 percent of the 140 or so sea otters living in Elkhorn Slough today are there as a result of the Aquarium’s surrogacy program. While we’d known that sea otters served as ecosystem engineers for the giant kelp forests in Monterey Bay, we have now documented that sea otters in Elkhorn Slough are restoring the health and biodiversity of the estuary. This gives us further insights into how sea otters may contribute to coastal ecosystem resilience. Continue reading Using science to save ocean wildlife
Monterey Bay Aquarium has since its inception affirmed that we are a science-driven organization, and that science underpins all of our public policy, research and education programs. That’s why we’re a partner with the national March for Science, a series of more than 500 events around the world on April 22.
As part of our commitment to the scientific process, our white shark research team works to understand and conserve these vital ocean predators. In advance of the March for Science, we’re taking a look at many of our scientific initiatives—in research, policy and education. Here’s a look at some of our recent white shark science highlights.
Annual Field Research
Every fall for the last decade, the Aquarium’s white shark research team has headed out to the Farallon Islands off the coast of San Francisco to tag, track, and identify white sharks as they feed on elephant seals and sea lions. The team observes behavior, captures underwater video, and deploys electronic tracking tags that relay information about white shark migrations and habitat preferences. When the team returns to the lab, they combine and analyze all these data to better understand white shark populations and their role in maintaining the healthy ocean ecosystems that ultimately support all life on Earth.