When wildlife officers with California’s Department of Fish and Wildlife raided two houses in the Sacramento area earlier this year, they found a live sturgeon gasping for breath, barely alive, on the floor in the garage of one. And in the other they discovered more than 20 jars of caviar, screens used to separate sturgeon eggs from the membrane that binds them together, frozen sturgeon meat, and scales for weighing meat and eggs.

In early May the Sacramento County district attorney’s office arraigned six men suspected of running a sturgeon poaching enterprise. They’re expected back in court on July 19 for a settlement conference, when information about the Sacramento case will be exchanged and a decision made as to whether a resolution can be reached without going to trial.

Although selling a wild sturgeon or its eggs is illegal in California, poachers aggressively target the fish for their meat and unfertilized eggs, which are made into caviar, says Patrick Foy, a captain with the fish and wildlife department. Since November 2013, 134 sturgeon violations have been recorded, most in the northern part of the state, for everything from possession of an untagged sturgeon, to unlawful gear use, to taking an undersized or an oversized fish.

A consumer buying legally made caviar from a California sturgeon farm can expect to pay anywhere from $70 to $400 an ounce. Black market caviar goes for about $100 to $150 a pound, according to the officer who led the Sacramento bust. (He asked not to be named because of the undercover nature of his work.) “It’s a huge discount if you buy it black market,” he says, but it can still add up to a big score for those willing to flout the law: The eggs from a single large sturgeon can fetch $3,000 on the black market.

In the past, countries around the Black and Caspian Seas have been ground zero for sturgeon poaching (and overfishing), for the beluga species, whose caviar is the most highly prized of all. Belugas are now critically endangered, along with another 15 of the world’s 26 sturgeon species. California has two of North America’s nine species—the green sturgeon and the white.

View Images A man extracts eggs from a sturgeon caught in the Amur River region, in Russia. Photograph by Reza, Getty Images

A United States ban on the import of beluga caviar has allowed California’s caviar business to boom. Made from the eggs of the white sturgeon, it’s considered an appealing substitute in terms of flavor and presentation.

But now California finds itself in a similar situation with its wild sturgeon as Eastern Europe’s beluga caviar-producing countries. Overfishing has long been a problem, and commercial sturgeon fishing has been banned in the state since 1954.

In 2006 the green sturgeon was listed as threatened under the federal Endangered Species Act, making it off-limits for recreational fishing. California’s fish and wildlife department notes that while the white sturgeon is not yet listed, its survival is considered “conservation dependent.” So recreational fishing of white sturgeons is now limited statewide to one fish a day, of between 40 and 60 inches long, and no more than three a year. (In the wild, white sturgeons can grow to 20 feet and live to be more than 100 years old.)

Both U.S. species are anadromous, meaning they swim from the ocean up freshwater rivers, like the Sacramento, to spawn. On this journey they face dams that hinder their progress. The ongoing drought in California, by lowering river levels, makes it even harder for them to reach their upriver spawning grounds.

Honor System

Sturgeons are highly vulnerable to illegal fishing because they begin breeding relatively late, at about age 15, and they spawn infrequently—only every two to seven years. If populations are depleted, recovery is slow.

In California, catching sturgeon poachers is challenging, says Chris Stoots, a spokesman and lieutenant with the fish and wildlife department. Fishermen are limited to taking no more than three sturgeons a year, and tags are issued to identify each one. At the end of the year, fishermen are asked to return a sheet called a sturgeon report card, on which they fill out data about the fish they’ve caught and kept or released.

Wildlife officers patrol the rivers year-round. If they catch someone with an untagged sturgeon secreted in an ice chest or a vehicle, for instance, the person is charged with poaching. But the state has only about 250 officers patrolling daily, far too few to catch every poacher, and they’re not even dedicated exclusively to sturgeons. “That’s for mountains, hills, valleys, rivers, creeks, streams, and 200 miles out to the ocean,” Stoots says. “Wrap your head around that one.”

People defraud the tagging system, Stoots says, by using duplicate tags, or a friend’s tags, or by not tagging at all and running the risk of being caught with a untagged fish. “It allows them to exceed that maximum three-per-year limit,” he says.

Penalties for poachers can range from fines of up to $1,000 or more to six months’ jail time per infraction to revocation of fishing licenses. One poacher, Nikolay Krasnodemskiy, was arrested in 2010 for selling sturgeon and their eggs on the black market. In 2014 he was sentenced to 75 days in a county jail, a $5,000 fine, three years of probation, a five-year fishing license suspension, and an order to stay away from the Sacramento River.

According to a statement from the California Department of Fish and Wildlife, the six suspects in the recent Sacramento bust could face thousands of dollars in fines, jail time, forfeiture of assets connected to illegal activities, and a loss of their fishing privileges.

Rachel Becker is a science journalist based in Northern California. Check out her website and follow her on Twitter.