A new study reveals the Aquarium’s Sea Otter Program bolsters the local otter population. Here, a surrogate-reared otter leaps into Elkhorn Slough on California’s central coast.
Ask not (only) what you can do for sea otters, but what sea otters can do for California.
That’s one of the thoughts on the minds of Aquarium scientists in the wake of a new study, which confirms the power of sea otters to restore coastal ecosystems.
Since 2002, the Monterey Bay Aquarium has reared rescued sea otter pups for release to the wild. Female otters in our exhibit serve as their “surrogate mothers,” teaching them critical life skills like how to groom themselves and forage. The hope is that when the pups are released in Elkhorn Slough, a wetland 20 miles north of the Aquarium, they’ll be able to thrive on their own.
A newly published study confirms that these surrogate-reared pups are surviving as well as their wild kin—and the resulting bump in the otter population at Elkhorn Slough is helping to restore the estuary ecosystem.
Glacier Bay National Park in Alaska is home to more than twice as many northern sea otters (Enhydra lutris kenyoni) as all of California is to southern sea otters (Enhydra lutris nereis). Studying the thriving northern species may hold important clues for the future of the recovering southern species. In August, Monterey Bay Aquarium researcher Jessica Fujii spent two weeks studying the Glacier Bay population in the wild.
When she’s not studying sea otters in Alaska during the summer, Jessica Fujii observes otter behavior around Monterey Bay. Photo by Michelle Staedler
Jess is a senior research biologist with the Aquarium’s Sea Otter Program. She studies both wild sea otters and pups raised by surrogate otters so they can be returned to the wild—as was the case with two juvenile males earlier this month.
“Mostly I’m looking at sea otter behavior and foraging ecology—what they’re eating and what that may tell us about the rest of the ecosystem,” Jess says. “It involves a lot of going out in the field and watching the otters from shore.”
“It looks like a fishing boat, but it’s been converted for research purposes,” she says. “What used to be the fish hold is now sleeping quarters and storage.” With six or seven others aboard, “it was cozy; there’s not a lot of extra space.”
The converted fishing boat Alaska Gyre was home base for scientists working in Glacier Bay.
The trip was part of a longstanding collaboration between the Aquarium and researchers with the USGS Alaska Science Center. The two groups sometimes share insights and help each other observe or capture sea otters: “Having that crossover can be really helpful,” Jess says. “It’s also a way to make sure we’re maintaining comparable methods.”
At our new Ocean Memory Lab, Monterey Bay Aquarium researchers are studying the global ocean and marine life in novel ways, to gain insights into a world before plastic and chemical pollutants were introduced to the water. Feathers, bones, teeth, bits of marine algae and other tissues from ocean plants and animals can paint a picture of conditions dating back a century or more. They’ve already learned how the feeding habits of seabirds have changed since the late 19th century, as PBS NewsHour Weekend producer Ivette Feliciano discovered when she talked with our director of science, Dr. Kyle Van Houtan.
Here’s her report:
We’ll share the latest news and updates about the Ocean Memory Lab in future blog stories.
For nearly 34 years, Monterey Bay Aquarium has harnessed the power of science to guide every aspect of our work—exhibit development, public policy and outreach, sustainable seafood solutions, research and education programs. In 2017, the Aquarium became one of the first 100 partners to support the first March for Science as a way to share our dedication to the scientific process. As the 2018 March for Science ramps up on April 14, we thought we’d revisit some of our greatest moments in marine conservation science over the last year. In these, and many other ways, we’re harnessing the power of science to make our world a better place.
Dynamic tuna dorsal fins
Researchers discovered Pacific bluefin tuna can move their dorsal fins with an internal hydraulic mechanism that aids in fast swimming and quick turns
While observing Pacific bluefin tuna inside the Tuna Research and Conservation Center (TRCC), scientists noticed something…fishy about the way they were swimming. TRCC scientists logged hours of video footage and, after conducting routine medical exams, discovered that the dorsal fins of tunas move both forward and backward as they swim—especially when they hunt for prey in quick flashes of speed. Their work, reported in a cover article published in Science magazine, documented that the team of scientists discovered a hydraulic mechanism that allows a tuna to articulate its dorsal fin along a range of angles depending on which behavior the tuna exhibits.
When evolution, animal behavior and body form meet in one elegant space, we call it “ecomorphology,” an area of expertise for Aquarium senior research biologist Jessica Fujii, who for years has studied how and why sea otters use tools. But when Jessica and her colleagues observed that sea turtles use their flippers like tools to swipe, slice and corral their food, we might call that “evolutionary serendipity”—something that sea turtles did not necessarily evolve to do, but do anyway. In a recent study published in PeerJ and led by Jessica, we learned that sea turtles use their flippers, largely designed for locomotion, to manipulate their prey. The scientists tapped crowdsourced images and videos from around the world to document turtles prying open scallops and karate-chopping jellyfish, confirming that this ancient marine reptile need not have a frontal cortex to perform such complex maneuvers. Because transparency is a key tenet of scientific inquiry, our team decided to make both the paper and the peer reviews of the paper available free to anyone with internet access.
Museum feathers reveal seabird diet changes
Some of the feathers in the study were from seabirds collected in the 19th century by groups like this 1885 party that landed in the Northwest Hawaiian Islands. The specimens are archived at the Bishop Museum in Hawaii. Photo courtesy Bishop Museum.
Naturalists hiking around the islands of Hawaii in 1890 could never have guessed that the seabird feathers they collected would someday be used to help tell the story of a changing ocean. But for Aquarium researcher Tyler Gagne, lead author on a new study of how seabird diets have changed over the last 130 years, the feathers played a vital role in reconstructing what seabirds have—and have not—been eating. Using stable isotope analysis, Tyler and his team traced specific chemical signatures found in the preserved seabird feathers to show how, over time, eight different species in the North Pacific have shifted from fish to squid, a transition that suggests both human and climate impacts are influencing their dietary choices.
For more than 30 years, sea otter researchers and animal care specialists at the Aquarium have been tagging, tracking, rescuing and rehabilitating stranded adult sea otters and pups. The data collected from 725 live strandings between 1984 and 2015 provide an intricate portrait of major threats California sea otters face as their population slowly recovers. Aquarium researchers determined that the absence of significant kelp canopy coverage at the peripheries of the sea otter range, especially in waters north of Santa Cruz and south toward Point Conception, can inhibit sea otters’ ability to reproduce and survive. Without sufficient kelp cover, sea otters, especially reproductive females and their pups, can be left vulnerable to shark bites.
Young white sharks: the wonder years
Juvenile white shark swims at the surface of Bahia Sebastian Vizcaino. Photo courtesy CICESE.
After years of studying the underwater lives of white sharks, Aquarium researchers and their partners in the United States and Mexico noticed some missing links in the life history of these apex predators. Where do white sharks give birth, and where do their pups grow up? Thanks to a study published in Fisheries Research, scientists discovered that Bahia Sebastián Vizcaino, a warm lagoon on the coast of Baja California, is a nursery for newborn white sharks. This study formalized a de facto understanding that southern California was the place to find young white sharks, but researchers validated a more surprising fact about juvenile white sharks: they don’t stay in Californian waters and they regularly travel to Mexican waters and back again.
These are just a few highlights reflecting the growing scope of ocean science taking place at the Aquarium. We’ll continue to conduct new science every day, to inspire new generations of science-literate citizens, and to use the best-available science to inform everything we do to assure a bright future for our ocean planet.
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 . . .
Exhibit sea otters like Rosa play a key role behind the scenes, as surrogate mothers rearing stranded otter pups.
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
Southern sea otters are a common (and adorable) sight off the Aquarium’s back deck. But the latest otter count shows the population isn’t growing at the pace we’d hoped it would. In order for the species to truly recover, otters need to return to their old habitats along California’s coast—places they haven’t inhabited for over 100 years.
For the second year in a row, California’s sea otter population index has topped an encouraging number: 3,090. That’s the minimum threshold before the U.S. Fish and Wildlife Service can consider delisting southern sea otters as a federally threatened species.
A southern sea otter with her newborn pup in the Monterey Bay Aquarium’s Great Tide Pool. Photo by Tyson Rininger
But the 2017 sea otter count is down quite a bit from 2016 levels, and even the three-year rolling average (the population index), on which federal wildlife managers base their decisions, is down by about 100.
Regardless of year-to-year variations, southern sea otters number far fewer today than they did historically, and their current geographic range represents just a fraction of the waters they occupied before fur traders drove them to the brink of extinction in the 19th century.
To reach the optimum sustainable population under the Marine Mammal Protection Act and the Fish and Wildlife Service recovery plan, the southern sea otter population would likely have to reach at least 8,400 animals in California alone.
“What we really want to see is the population reinhabiting areas of its historical range,” says Andrew Johnson who, as conservation research operations manager for Monterey Bay Aquarium, oversees the sea otter program. “We’ve seen how positively coastal ecosystems respond to the presence of sea otters—from the return of thriving kelp beds along the rocky coast, to renewed productivity of wetlands like Elkhorn Slough. We know that many other areas along the California coast would benefit significantly from sea otters’ return.” Continue reading California’s sea otters need more space to grow
On Earth Day, Monterey Bay Aquarium staff and volunteers joined in March for Science events along with tens of thousands of people in more than 600 cities around the world. With representatives at marches in seven cities across the U.S. and Europe, the Aquarium stood up for one of our founding principles: that evidence-based science should drive conservation action.
From recording and sharing wildlife observations to reporting stranded sea otters, there are many ways to contribute as a citizen scientist.
It’s clear that the March for Science isn’t just about scientists, and it’s more than a one-day phenomenon. People of all ages and backgrounds participated, because you don’t have to be a trained scientist to appreciate the benefits science offers—or to contribute to the scientific process.
Much of the science taking place at the Aquarium, from saving sea otters to tracking white sharks, relies on dedicated citizens quite literally taking science into their own hands. Thanks to our increasingly connected society, opportunities abound for everyone from middle school students to retired teachers to participate in citizen science at the Aquarium—and beyond. Here are a few of the many ways you can become a citizen scientist. Continue reading Playing your part through citizen science
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.
A sea otter works to crack a mussel shell open on a rock off the coast of Moss Landing, California. Photo by Jessica Fujii
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.
A sea otter rests in an eelgrass bed in Elkhorn Slough National Estuarine Research Reserve. Sea otters contribute to the recovery of eelgrass and ecosystem health in this vital wetland on Monterey Bay. Photo by Ron Eby.
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
Otter 501 meanders through the tidal creeks near Yampah Island in Elkhorn Slough with a dozing pup on her chest. She massages the pup’s rump and blows air into its fur as she makes her way toward a main channel to feed.
To an observer, 501 might look like any other sea otter going about her business. But she’s thriving in the wild today because of a rather remarkable program at Monterey Bay Aquarium.
According to surprising new research, the same can be said of the majority of Elkhorn Slough’s otters.
What makes people different from other animals? Scientists used to think the ability to make and use tools was a distinguishing characteristic. That changed in the 1960s, when Jane Goodall observed chimpanzees using sticks to fish termites out of mounds. Now, crows, dolphins and sea otters make the short list of creatures that use tools.
Sea otters dive in shallow coastal waters to collect hard-shelled prey like sea urchins, mussels, abalones, clams and snails. Some shells, like the calcium carbonate armor that protects snails, are harder to crack than others—so otters sometimes use rocks as anvils to break them open.
Conservation & Science 