Mongabay.com: With a target on their bellies, can California’s sturgeon survive?

 

Following up on a tip to the state’s poaching hotline, game wardens in California rushed to a popular fishing spot, Clifton Court Forebay, in the Sacramento-San Joaquin River Delta. They’d received a tipoff about an individual allegedly catching a green sturgeon (Acipenser medirostris) and stuffing it in his SUV.

They tracked down the suspect using photographs submitted by the tipster. The fish was in the back of his vehicle, barely alive. The wardens quickly issued a citation and rushed the 165-centimeter (65-inch) ailing sturgeon to the nearby marina.

For 90 minutes, they worked to revive the fish. They submerged it in the water and, crouching on the boat ramp, rocked the animal back and forth to run water through its gills and provide oxygen as if it were swimming. At last, the fish rallied and swam away, presumably healthy enough to survive.

This was in 2022, but it’s far from an isolated incident, noteworthy because it had a happy ending. California’s Department of Fish and Wildlife (CDFW) officers periodically discover anglers taking sturgeon illegally, as they did while patrolling the Sacramento River early this year, when they spotted two groups of suspected sturgeon poachers. Each had caught a large fish and tied it off some 91 meters (100 yards) away in a seeming effort to conceal it.

But the wardens weren’t fooled. They seized the fish and set them free.

In California, and worldwide, poachers target sturgeon for their eggs, which become a coveted delicacy when processed into caviar. Caviar from California’s white sturgeon (Acipenser transmontanus) is highly prized: It’s been compared to that from the critically endangered beluga sturgeon (Huso huso) from Eurasia, which is the world’s most expensive.

California protects both of its sturgeon species, white and green sturgeon. Keeping, killing or selling wild sturgeon or their eggs is prohibited; the state banned commercial sturgeon fishing 71 years ago, in 1954.

Globally, sturgeon populations are dropping, with 85% of species at risk of extinction.

“Sturgeon are one of the most highly threatened groups of species on Earth,” says Monika Böhm, freshwater conservation coordinator at Indianapolis Zoo’s Global Center for Species Survival. “All species are threatened, although in some parts of the world [like Europe and Asia], it’s worse than others.”

While poaching is known to occur in California, the true population-level impact is hard to determine, says Jon Rosenfield, science director at San Francisco Baykeeper, one of the organizations that petitioned the state and federal governments to list sturgeon as endangered species.

Caught for caviar

While many sturgeon poaching incidents are occasional acts, the CDFW has tracked poachers to caviar processors and sellers, with some linkages to criminal networks also involved in other illegal activities.

One of these cases launched an 18-month investigation. Wildlife officers ultimately netted an eight-person poaching network in 2021 that the press dubbed “the Caviar Kings of Contra Costa.”

Two of the accused were repeat offenders. All were charged with a slew of offenses, including conspiracy to poach sturgeon, multiple fishing violations and intention to sell the fish and their products on the black market. Some of the suspects were observed catching and using juvenile salmon as bait to catch sturgeon, which is also illegal.

With search warrants, wildlife officers seized five illegal firearms, including a handgun, a “ghost gun” with no serial number and an AR-15 assault rifle; more than 453 kilograms (1,000 pounds) of illegal cannabis; and more than $57,000 in cash and counterfeit currency. Investigators linked the poachers to middlemen who were suspected of processing sturgeon eggs into caviar and selling it on the black market.

And in 2013, CDFW wardens arrested two men for poaching 18 sturgeons in 10 days, and discovered more than 14 kg (30 lbs) of eggs ready to process into caviar.

The incidents add up. For sturgeon, taking even very small numbers can affect the future viability of the population, which is a significant issue when numbers of these ancient fish are already low and they’re threatened on numerous other fronts.

However, “it’s hard to imagine [that the population impact of poaching] approaches the three main drivers of the fish’s decline,” Rosenfield said, noting that the greatest threats are water system management, including dams that reduce river flows and block connections between water systems; harmful algal blooms; and overfishing.

An ancient fish at risk

Sturgeon look prehistoric, which makes sense since they’ve been around since the days of the dinosaurs. “Sturgeon have witnessed the continents move apart,” says John Kelly, CDFW’s sturgeon coordinator. “They’re truly ancient fish.”

“They’re otherworldly, from a different time,” the Indianapolis Zoo’s Böhm says. “It’s fascinating that they’ve made it this far.”

They are odd-looking creatures, with elongated snouts, mouths that can stick out to vacuum up food, and whisker-like barbels they tap along the river bottom to detect prey. Five rows of bony, diamond-shaped scutes run along the length of their bodies for protection. Notably, white sturgeon are the largest species of fish living in North America’s freshwaters, growing up to 6 meters (20 feet) long.

Journalist Hannah Nordhaus offered an apt description. “Cross a catfish, a shark, a stegosaurus and a pruning saw and you’re not far from imagining a sturgeon,” she wrote.

As a bottom dweller, this fish feeds on crustaceans and other species. For millennia, they’ve played a key role in keeping their ecosystems healthy, so impacts from their decline reverberate throughout their riverine homes.

Their natural history means that they may or may not bounce back after losses. All of the world’s 25 sturgeon species grow slowly and mature late.

Like salmon, most sturgeon species start their life in freshwater, migrate to bays, estuaries or the ocean for some portion of their adult lives, though a few spend their entire lives in freshwater. Then, when it’s time to spawn, they swim back upriver.

While that’s the end of life for salmon, white sturgeon spawn multiple times, typically once every two to five years in California, with populations farther north often having longer intervals.

They reproduce from the time they mature — typically when they’re 12-16 years for females and earlier for males — until they die, and they are incredibly long-lived. California’s white sturgeon can live for a century or more.

“It’s a strategy that has allowed them to persist for a long time,” Kelly says.

But they need the right conditions to reproduce. “They spawn successfully when river flows are above a certain level, and above that threshold, success increases,” Rosenfield says. However, “a lot of water is taken out of rivers.” In years with low river levels, there’s little or no spawning. “If [spawning] doesn’t work out one year, they come back later,” Kelly says.

Female sturgeon can skip spawning when conditions aren’t right. They can reabsorb the eggs and try again when circumstances are better. While that can increase the survival chances for young sturgeon, it can be a liability for adults bursting with eggs, because it puts them in the rivers where they’re more vulnerable to being caught.

The sturgeons’ late maturity and complex reproduction means, Böhm says, that “they can’t get themselves out of trouble quickly to make up for the threats that impact them.” “Once you have diminished populations, it gets to the stage where you need to think about reducing any other mortality to that species.”

A target on their bellies

Typically, fishers search for sturgeon using fish finders, then deploy heavy-duty tackle, smelly bait like salmon roe, and barbless hooks to catch them. Catch and release is permitted under certain conditions. Once a sturgeon is on the line, fishers reel them close to the boat and lift them with a net to release them. But these large, heavy fish can be easily injured if they’re pulled into a boat or dragged or carried onshore.

Because males and females look the same, poachers don’t know whether fish have eggs. So they slice them open to find out, inevitably killing them.

The scooped-out eggs are then salted and cured to make caviar.

Historically, caviar only came from sturgeon that swim the Caspian and Black sea basins — especially beluga, osetra or Russian sturgeon (Acipenser gueldenstaedtii), and sevruga or starry sturgeon (Acipenser stellatus). But then, in the 1970s, the beluga sturgeon was nearly wiped out from overfishing. Populations dropped by 90%.

That led to fishing bans and trade restrictions. In 2002, Russia prohibited commercial sturgeon fishing and caviar exports. Then, in 2005, the United States — which consumed 60% of the world’s beluga caviar at the time — banned imports.

The next year, international trade was temporarily banned under CITES, a treaty signed by 184 nations and the European Union to regulate the international wildlife trade. That made it illegal to export wild sturgeon products like caviar. However, those decisions didn’t affect domestic consumption.

Demand for sturgeon didn’t stop, creating a growing sturgeon farming industry and searches for other species that could supply the global caviar market. In the U.S., domestic sturgeon farms stepped into prominence as white sturgeon became a premier source.

Caviar from white sturgeon is high quality, Kelly says. “Their eggs have a texture and ‘pop’ that’s preferred. By comparison, green sturgeon eggs are very large, but have a thin outer membrane, so they break up.”

Before long, California became the heart of the nation’s cultivated caviar industry. Sturgeon farming allows harvesting the eggs without killing the fish. Farmed caviar is generally of highest quality because these fish are raised under optimal conditions and the eggs are harvested at their ripest.

Prices reflect that difference. Caviar from California farms sells for $400 to $1,000 per pound, depending on the grade; wild caviar goes for around one-third that amount.

Under threat

Sturgeon are the most threatened group of animals in the world, according to the IUCN, the global wildlife conservation authority: 85% of species are threatened and 64% are critically endangered.

In California, populations have been in decline for 70 years. Kelly, CDFW’s sturgeon coordinator, says the state’s white sturgeon population “may be the lowest it has ever been, based on recent data.”

There are roughly 19,000 sturgeon between 25 and 220 centimeters (10 and 87 inches) left in the state, according to a 2024 CDFW survey. That’s down sharply from the 30,000 fish of 101-152 cm (40-60 in) that were estimated from 2016 to 2021. And it’s an enormous drop from 1980s numbers, when officials estimated that 150,000 to 200,000 mature sturgeon of that size swam California’s waters. Historically, researchers only counted large fish because those were the ones people targeted.

However, it’s hard to make accurate comparisons because the most recent sturgeon survey used a different methodology than previous ones.

Ongoing declines

There are multiple reasons for the declines. “Top on the list are habitat issues related to water flow and quality,” Kelly says, which are impacted by diversions, temperature, runoff and pollution.

Then there was high mortality from harmful algal blooms, or red tide, in 2022 and 2023.

“Big blooms turned large sections of the bay red,” Rosenfield recalls. “We [at San Francisco Baykeeper] found sturgeon and all sorts of fish washing up on shore.” Uncountable numbers of fish died. “One field investigator saw 10,000 fish in one field of vision on one day in the bay,” he says.

“[Seeing] such a large percentage of the standing stock killed in 2022, and again in 2023, made us realize they’re imperiled,” Rosenfield says, prompting a petition to list white sturgeon as a threatened species.

California’s shifting regulations

Sturgeon fishing in California is restricted. The rules are, however, a bit convoluted, with different regulations for the state’s two species.

Capture or possession of green sturgeon has been illegal since 2006, when it was listed under the federal Endangered Species Act. But the rules for white sturgeon have been ever-changing based on new information, varying year to year.

Up until 2024, recreational anglers were allowed to catch and keep white sturgeon, with limits on quantity, size and where and when they were caught. But overfishing has taken a toll. A 2019 study found that the 8% yearly harvest rate for recreational sturgeon fishing was too high to maintain a stable population; a sustainable harvest should be less than 3% per year.

However, the rules changed in 2024 when white sturgeon became a candidate for listing under the California Endangered Species Act. Harvests are no longer allowed.

But the lines between what’s legal and what isn’t can easily blur.

While nobody is allowed to keep white sturgeon, recreational anglers can still fish for them — as long as it’s catch and release, and done at certain times of year and in specific locations.

For example, it’s allowed from Oct. 1, 2025, to June 30, 2026, in the ocean, San Francisco Bay and Delta, and the lower Sacramento and San Joaquin rivers. But it’s prohibited in the upper stretches of these rivers and in tributaries.

This makes poaching difficult to prosecute. Often, the accused claim they weren’t fishing for sturgeon but rather trying to catch something else. Unless wardens can prove otherwise, there’s little they can do.

“We have to have evidence that can disprove what they’re saying,” says a veteran undercover CDFW officer. “We have to catch them in the act.”

Unknown impacts

While sturgeon poaching is worrisome, the true impact is unclear. Poaching “has been identified as a threat to the population,” states the petition to list white sturgeon as threatened in California, but it notes that “there are no data on the current magnitude of this problem.”

“We know the poachers we catch, not the ones we don’t. “ Rosenfield says. “[Sturgeon] are an attractive target.”

But enforcement is challenging. “CDFW does a good job with limited staff in a gigantic bay and watershed,” Rosenfield says. “But it is a gigantic bay and watershed, and it’s very difficult and expensive to be everywhere at once.”

Poachers tend to target sturgeon at the most important time of year — during the spawning migration, when it’s easiest to find them — and they go after the biggest fish that will have the most eggs.

“A 4-foot [120-cm] sturgeon might have 70,000 eggs,” Kelly says, “while an 8-foot [240-cm] fish produces 500,000 eggs.”

The good news is that, with white sturgeon listed as a candidate species for protection in the state, officers say they’re seeing fewer poachers out there. Wardens think that periodic closing of recreational catch-and-release fishing, combined with increased public awareness and the threat of higher penalties, may be prompting poachers to think twice. “It’s definitely deterring some folks,” the undercover officer says.

With protected status, poachers could face fines of up to $25,000 per infraction, a dramatic change from current fines of $1,000, as well as up to six months in prison per arrest. Poachers could also be forced to forfeit property used for illicit capture, including boats, vehicles and fishing gear. Before it was a candidate species, violations were considered misdemeanors under California’s fish and game regulations.

But sturgeon face many challenges, with poaching sitting down on the list.

California’s extensive water management system has a significant impact on sturgeons’ ability to thrive and reproduce.

“The San Joaquin River has the nickname of the ‘hardest working water in the world’ due to an extensive system of dams, diversions and engineering,” notes a 2016 study published in the Journal of Fish and Wildlife Management.

The goals of this system, the authors say, are “fundamentally incompatible with maintaining the natural conditions under which native fishes, including white sturgeon, evolved. Intense water management has altered natural environmental conditions, including streamflow, sediment transport, water temperature, floodplain connectivity and access to upstream habitats,” while diversions have lowered both water quantity and quality, all of which are critical for sturgeon habitat.

Add in all the other stressors, from pollution and harmful algal blooms to climate change, dredging, vessel strikes and poaching, and it’s impressive that these benthic behemoths are still around.

But sturgeon are survivors. Their flexibility has allowed them to compensate for catastrophic changes over millennia.

“If left alone, even slow-reproducing species can get to a stable set up. But when there are threats on the species, this recovery is more difficult to achieve,” Böhm says. Given that the hazards are mainly human-induced, “it’s less on sturgeon to get themselves out of trouble — and more on us.”

 

Laurel Neme is a freelance journalist and author of books for adults and children, including Animal Investigators and The Giraft: A Real-Life Giraffe Rescue, forthcoming in 2026.