Fighting for a Foothold

White abalone are both critically endangered and crucial to their coastal ecosystems, so scientists have launched a Hail Mary effort to save them.

Kristin Aquilino pushes open a heavy metal door with a small sign bearing the words, White Abalone Spawning and Culturing in Process. “This is where the magic happens,” says Aquilino, who directs the white abalone captive breeding program here at the UC Davis Bodega Marine Laboratory, an expansive research facility situated on a windy, jagged stretch of coastline in northern California. It’s shortly after 7 a.m., and she and her team have already been at work for several hours.

Today is Spawning Day—the one time each year when white abalone can be coaxed to release their sperm and eggs, giving researchers the chance to rear the next generation. Each of the 14 brood stock in their care, including the only wild white abalone female in captivity, sits in its own bucket, bathing in a hydrogen peroxide solution that, after a few hours, should stimulate the mollusk to spawn. “There’s a lot on the line,” Aquilino explains. With white abalone (Haliotis sorenseni) failing to reproduce in the wild, this program is essential to the species’ survival. But she doesn’t have high hopes for the new wild female, which released eggs out of stress when divers collected her in Southern California a few weeks earlier. “My guess is she’s done.”

White abalone once numbered in the millions, from Point Conception, near Santa Barbara, California to Punta Abreojos, Mexico, more than 1,200 kilometers (800 miles) to the south. Today, only about 2,000 isolated survivors remain along California’s coast, where the species is considered to be functionally extinct. No two individuals live near enough—within 2 meters (6 feet) of one another—for their sperm and eggs to meet when released into the water. As white abalone numbers have fallen, other creatures have proliferated in their wake. Urchins now overgraze the fragile kelp forests that protect coastlines from eroding into the sea. Despite conservation efforts, abalone numbers have continued to drop in recent decades. Researchers have been left with no choice but to try to breed the animals in captivity and release them into the wilds of the California Coast in a last-ditch effort to save the species—and the habitat they shore up.

Just after 9:00 a.m., an hour earlier than anticipated, there’s a sudden flurry of activity as technicians cluster around one of the white buckets. Wild abalone 312 is spawning. “You go girl!” yips Aquilino, as a cloud of brown eggs shoots out of one of the respiratory pores on her shell—an orifice through which the animals both breathe and release eggs or sperm. Given the unlikelihood that this abalone lived near a male in the wild, Aquilino says this could be the first time she’s had a chance to reproduce in decades. “That’s a very long dry spell,” Aquilino says, especially for an animal with a lifespan of 35 to 40 years. Ten minutes later, in 309’s bucket, a cloud of milky abalone ejaculate plumes, and technicians swiftly elbow their way in with pipettes to collect the sperm. In a matter of minutes, Aquilino is inside a refrigerated fertilization room and singularly focused, mixing the fresh sperm and eggs in precise ratios. “It’s like with 309 and 312,” she says, injecting a dropper-full of sperm into a pitcher of eggs.

After more than a decade of trial-and-error, white abalone are finally hitting their stride in captivity. By day’s end, the wild female will have spawned some 700,000 viable eggs—introducing new genes into the captive population for the first time in 14 years. In total, the team estimated they had created 8 million embryos—20,000 of which they expect to make it to the adult stage. That’s in addition to the tens of thousands of juveniles researchers have already reared in their nursery.

As scientists prepare to release the first captive-bred individuals into the wild in the next year or so, much remains unknown about the ecological role of the marine invertebrate and the rising threats to their long-term recovery: a mysterious disease brought on by warm waters; the predators that exploit naive captive-raised abalone; and the yet-to-be-determined impacts of climate change. Indeed, the coast is hardly clear for abalone in California.

In the wild, white abalone typically live a hundred feet or more below the surface, so researchers often use remotely-operated submersible vehicles to study them. As a result, research on the basics of abalone biology and ecology has been slow, and scientists were largely unaware of the rapid decline of abalone populations until it was almost too late.

“Abalone’s ultimate downfall is that they’re delicious,” says Jenny Hofmeister, a marine scientist at the Scripps Institution of Oceanography. White abalone, highly prized by markets in Asia and restaurants in stateside Chinatowns, are said to be tastier than the red, black, pink, or green abalone species. In the 1970s, California opened up a commercial fishery for white abalone, and divers gathered the animals by the hundreds of thousands. As white abalone became rarer in the wild, the price per pound jumped from $2.50 in 1981 to $7 in 1993—roughly double the value of other abalone species. Before long, the abalone that remained on the seafloor were too few and far between to reproduce.

Fearing extinction, the California Department of Fish and Game banned commercial fishing of white abalone in 1996 and in all abalone species in 1997. Today, the only fishery that remains is for recreational fishing of red abalone in northern California, where densities are still sustainable. But that hasn’t stopped white abalone from showing up in fishermen’s hauls. Today, a single white abalone can sell for hundreds of dollars—a temptation some divers are unable to resist. Aquilino says she’s heard people describe it as “finding a $100 bill on the ocean floor.”

Based on surveys conducted in the 1990s showing that white abalone density had declined by 99 percent in southern California in just two decades, the species was designated as a candidate for listing under the Endangered Species Act. Petitions from the Center for Biological Diversity and the Marine Conservation Biology Institute eventually led to the white abalone being listed in 2001—the first marine invertebrate to receive federal protection. In the years that followed, scientists and the government mounted a valiant effort to bring the animal back from the brink, but white abalone numbers continued to drop. Between 2002 and 2011, some of the sparse, wild California populations declined by an additional 78 percent.

“Something knocked them out,” says Buzz Owen, 82, a retired commercial fisherman and avid abalone researcher who first described hybridization among various species. “But there were multiple things at work.”

On top of illegal harvests, a disease called Withering Foot Syndrome first showed up near the Channel Islands off the southern California Coast in 1986, and by the 1990s it had spread to waters near the mainland. Once infected, abalone stop eating. The abalone is then forced to consume its own body mass, causing the foot muscle to wither and lose its life-giving grip on the rocky seafloor. The deadly disease affects every abalone species in California, but white abalone are particularly hard hit.

Even more troubling, the emergence of Withering Foot Syndrome is temperature-dependent. A white abalone in a lab, under optimal conditions, can be infected with the pathogen and not experience any symptoms. But as soon as the water temperature warms to between 18 and 20 degrees Celsius (64 and 68 degrees Fahrenheit), the disease kicks in, killing the mollusk within months.

In the wild, white abalone occupy deep waters that are normally cool enough to keep them healthy. But between 2014 and 2016, El Niño and an anomalous mass of warm water meteorologists call “The Blob” pushed temperatures in the eastern Pacific Ocean two degrees Celsius above normal. This warmed every monitored white abalone site in southern California, some of them past the 18-degree threshold. Climate change is expected to routinely bring warmer water temperatures to some stretches of white abalone habitat, potentially eliminating their thermal protection in these areas altogether.

To make matters worse, rising ocean temperatures are also wreaking havoc on the animals’ habitat and food sources. Kelp forests need temperatures between 5 and 20 degrees Celsius (41 and 68 degrees Fahrenheit) to thrive. When water temperatures increase, the amount of dissolved inorganic nitrogen drops and kelp abundance begins to fall as well.

A Brief History of White Albone

Thanks to over-harvesting, reprroductive failure, and infections, white albone from abundant to endangered in just half a century. But science has been staging and intervention in hopes of improving the species’ odds of survival.

1968White abalone harvest takes off in California1978White abalone harvest plummets; a mere 3,600pounds are harvested this year1972At its peak, 144,000 pounds of whiteabalone is harvested in a year2001White abalone is federally listed as anendangered species1997California prohibits commercial and recreational fishing of white abalone2002-2014White abalone numbers at a monitoring site in Tanner Bank, California continue to fall despite protections1960197019801990200020102020An estimated 2 to 4 million white abalone inhabit the California and Mexico CoastsDespite conservation efforts,populations declineIndividuals are too few and spread out to reproduce successfullyIntervention, such as captive breeding, is necessary to prevent extinction

When I meet Jim Moore inside the California Department of Fish and Wildlife’s Shellfish Health Lab, the invertebrate pathologist is peering through a microscope, examining dyed tissue samples taken from captive white abalone. He’s hoping that by documenting the process of necrosis—what an abalone’s tissues do after the animal dies—he’ll be able to sort out the difference between changes caused by pathogenic disease and those that happen naturally after death. “It’s difficult for us to figure out when an abalone is really dead—often once [researchers] realize, it’s been dead for a while,” he says. This makes it hard to know if an infection took hold before the animal died (perhaps causing death) or after.

To keep Withering Foot Syndrome at bay in the nursery, Moore gives the animals a bath in an antibiotic called oxytetracycline and treats them with UV radiation as soon as they arrive. Researchers can douse the animals once more before stocking them in the wild, to protect them from the disease for a few more months, but without continual treatment the abalone are likely to get infected.

In a stroke of evolutionary good fortune, a bacterial phage, or hyper-parasite, emerged a few years ago, fighting off the syndrome in wild populations of black abalone, as well as on red abalone farms in central California. In black abalone, for example, researchers found the phage reduced the infection load in targeted tissue by roughly half. The phage has since spread and is protecting abalone populations throughout their range, wherever the pathogen is found. Moore says researchers have no clue where it came from or how it arrived, but “the enemy of your enemy is your friend,” he says. The phage has shown mixed results to date in saving white abalone, but considering its enigmatic nature, there’s hope that the phage, or another variant, may turn out to provide some level of protection.

Progress has been made in keeping illegal harvest to a minimum, though. To pin down poachers, Erin Meredith, senior wildlife forensic specialist for the California Department of Fish and Wildlife’s Wildlife Forensic Laboratory, helped to develop a genetic test to distinguish between red, black, pink, green, flat and white species. Now, when enforcement officers come across suspected abalone poachers in the field, they can take tissue samples from the poached abalone and send them to a lab for species identification. Meredith’s test also enables officers to have items used in the potential violation analyzed, such as the suspect’s dive gloves, wetsuits and pry knives—anything that may have come into contact with the abalone. And it’s working. Earlier this year, Meredith received her first case involving potentially poached white abalone in southern California.

The challenge that remains is figuring out how and where to return the captive-bred abalone to the wild once researchers receive federal approval to release them, hopefully, within the next year. Even if scientists manage to protect abalone from poachers and disease, predators threaten to undo all the gains their hard work has achieved so far.

The 22-foot the Boston Whaler dubbed Kelpfish rolls in the choppy waters off San Diego as pelicans dive like sharpshooters around the boat, snapping up fish and gulping them down quivering gullets that reverberate with each flop. Sea lions and porpoises swim by, taking advantage of the ocean’s bounty. On the horizon, a California Department of Fish and Wildlife enforcement officer patrols the protected waters, on the lookout for possible poachers. But today, most of the action is happening far beneath the waves.

After 45 minutes, a stream of fizzing bubbles rises to the water’s surface, signaling the return of divers Jenny Hofmeister and Arturo Ramirez. The two waterlogged black shapes emerge from a cloud of tuna crabs and weedy kelp and haul themselves from the cool water along with mesh bags filled with a collection of sea creatures. After a quick swig of ginger tea to warm up, Hofmeister begins sifting through her scavenged treasures: an empty cowrie shell; five Kellet’s whelks; a starfish; and a half-dozen red abalone shells, their occupants long-since eaten.

Over the past week, Hofmeister and a team of divers from the Bodega Marine Laboratory have been performing predator surveys in a range of stocked habitat plots along the California coastline. Last year, to test the waters, the team released 3,200 farm-raised red abalone in Long Beach—a process they call outplanting. “We saw a very quick and immediate increase in octopus right next to our abalone a few days after we put them out there,” Hofmeister says. “We call it ‘ringing the dinner bell’.”

Octopuses are abalone’s most voracious predator in deep water, but crabs, lobsters, and fish will target them, too. Captive-bred abalone released into the wild, researchers theorize, are stressed in their new environment and haven’t developed fast-acting fear responses yet. The abalone’s first lines of defense are passive: camouflage and a hard shell. If pursued by a slow-moving predator, like a starfish or predatory snail, abalone can retreat, if only at a literal snail’s pace. When faster-moving threats approach, abalone can engage their mollusk death grip, clamping down on a rock and holding on for dear life. But studies show that farm-raised abalone don’t clamp down fast enough. And even if they do, some predators, like octopuses, are able to bore through their shells.

Hofmeister pulls out her waterproof chart and begins performing casual necropsies on each of the red abalone shells she’s collected. “Damage to the shell can give us an indicator of what ate it,” she says, picking up a tiny green and gray shell with chips along the edge. “This was probably a crab or a lobster, because they’ll use their sharp claws to flip the abalone off the rock.” Octopus kills, she continues, can be identified by the pin prick-sized hole it makes through the middle of the abalone shell with its rasping tongue to reach the main muscle, where the octopus injects a paralyzing toxin. This allows the octopus to pry the abalone off the rock and devour it. “There is not much we can do to increase the armor of the abalone,” Hofmeister says. “If we can find a way to deter octopus, that might be our best bet.”

So far, about 700 of the 7,200 outplanted red abalone from the trial have been accounted for across nine sites in coastal Los Angeles and San Diego, 400 of them dead and 300 alive. The site Hofmeister is monitoring today seems to be showing better survival rates than other locations as well as fewer predators. As she packages each abalone shell in a small plastic bag, another dive team swings by in their boat and passes over a white plastic bucket containing a California two-spot octopus (Octopus bimaculoides) collected at one of their survey plots.

“A lot of my research is addressing how we can outsmart the octopus,” says Hofmeister as she hoists the slimy, red mollusk from the water in the bucket, already stained with the animal’s defensive ink. She empties the toxic contents over the side of the boat as the octopus suctions tightly to her hand. Because octopuses use their tentacles to “taste” their way along the seafloor, Hofmeister wonders if it would be feasible to coat the abalone’s shell with an unpalatable concoction to deter predators. She explains, “We want a coating that doesn’t hurt the abalone, but if an octopus touches it, he’s like ‘Nope!’” Alternatively, if researchers find areas that octopuses steer clear of—a patch of sandy terrain or rocky relief too unpleasant to traverse—these might be good spots to release white abalone.

Hofmeister pulls out her measuring stick and takes a read of the size of the octopus’s mantle. Then she checks for any physical damage; tentacle R2 is missing its tip, but it will regrow. Last, she sexes the octopus and estimates her to be six months old. By year’s end, she’ll double in size. “Don’t ink, don’t ink, don’t ink,” Hofmeister mutters as she returns the animal back to the bucket of water.

She inks.

By mid-afternoon, our boat is harbor-bound, speeding over dark blue waters. The clouds that hung low throughout the morning have dissipated, and the mansions of San Diego loom large above the shoreline. Mitt Romney has a $12 million beachfront vacation home here, not far from John McCain’s $1 million luxury condo.

One of the biggest challenges of white abalone restoration is getting people to care about an animal that so closely resembles a rock. Abalone are the antithesis of charismatic megafauna. Still, Aquilino is on a mission to make the world see these creatures as both “cute” and vital to the ocean’s health. If people can look past the animals’ hard exterior, they may invest more in saving abalone, which play a critical role in maintaining the nation’s kelp forests and the coastlines these ecosystems hold together.

In this part of southern California, where white abalone have all but disappeared, sea urchin populations have exploded over the past 20 years, forming so-called “urchin barrens.” With no abalone around to compete for habitat and vital resources, urchins move out of subtidal cracks and crevices to mow down kelp and the ecosystems the plants support. In California, it’s these kelp forests that protect coastlines from wave action. “They absorb a lot of the ocean’s energy,” explains Hofmeister. As sea levels rise, waves will likely be able to travel farther inland, even during calm conditions, eroding away land. Storm surges bring larger waves, and with them, the potential to cause catastrophic damage. “Without kelp forests, Romney’s house is going to be gone,” she says.

According to a 2013 study in Nature, if protective nearshore habitats such as kelp forests were lost, we would see a doubling of the number of poor families, elderly people, and property value exposed to coastal hazards like flooding and sea level rise by 2100. And without abalone, kelp forests’ days may be numbered. It’s not just a matter of getting people to acknowledge that abalone are cute; the mollusks provide tangible, measurable economic benefits in the form of coastal protection.

“The kelp forest is an ecosystem that supports a lot of different species,” explains Hofmeister. Remove one of those species, and the whole ecosystem can crumble. When sea otters disappeared in the Aleutian Archipelago in southeast Alaska, for example, urchins exploded and ate all the kelp until the forest disappeared, and with it many of the species it supported, such as seals, sharks, and sea lions. But when sea otters were extirpated in southern California, where other species that preyed on the urchins still existed, the forests remained resilient. “The more biodiverse an ecosystem is, the more resilient it is to change,” Hofmeister says. “Diversity saved the kelp forests then, and diversity is what is going save the kelp forests now.”

Interactive by James Davidson

Photo credits:   

Header: A white abalone at the Bodega Marine Lab. Photograph by John Burgess/The Press Democrat 
The Bodega Bay Marine Lab in Horseshoe Bay 
The Shellfish Health Lab.  
A dyed sample of diseased abalone tissue.  
Homes overlooking the waters of San Diego. Photograph by Gloria Dickie.  
Footer: The rocky coast of Northern California.  

Gloria Dickie

Gloria Dickie is a freelance science and environmental journalist based in Boulder, Colorado. Her work has appeared in National Geographic News, High Country News, Hakai Magazine, Quartz, Outside, Discover, Mongabay, and many other publications. Follow her on Twitter @gloriadickie and read more of her work at

Kathryn Whitney

Kathryn Whitney is the former Photo Editor and Photographer for the California Academy of Sciences and bioGraphic, where she was able to combine her passions for science and photography every day. She is always ready for adventure, whether it’s outlasting a hailstorm while on assignment or galloping semi-wild horses across the Mongolian Steppe.

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