In 2019, this California sea creature was heading toward extinction; scientists raised babies in captivity and returned them to the ocean

For decades, the white abalone quietly disappeared from the waters off California. Once abundant enough to support a commercial fishery, the marine snail suffered such a severe collapse that scientists feared it could vanish altogether. Then, in November 2019, researchers attempted something that had never been done before: they carried hundreds of captive-bred youngsters beneath the Pacific and placed them back into their historic habitat.

How Did White Abalone Nearly Disappear?

White abalone (Haliotis sorenseni) live on rocky reefs off Southern California and Baja California, at depths reaching around 60 metres. Heavy commercial fishing contributed to a dramatic population decline beginning in the 1970s. By 2001, the situation was so serious that white abalone became the first marine invertebrate federally listed as endangered in the United States. California's Department of Fish and Wildlife says recovery in the wild remains unlikely without human intervention. Their biology creates another problem. Abalone release eggs and sperm into the surrounding water, meaning adults generally need to be relatively close together for successful reproduction. When populations become extremely sparse, finding a mate becomes increasingly difficult.

Scientists Decided to Raise a New Generation

Rather than wait for the remaining population to recover naturally, NOAA Fisheries and its partners developed a captive-breeding programme led by the UC Davis Bodega Marine Laboratory. The programme achieved a remarkable breakthrough in April 2019. Ten adult white abalone produced and fertilised 25 million eggs. Millions of larvae were subsequently distributed to partner facilities in Southern California to be raised for conservation work. Kristin Aquilino, who led the programme at UC Davis, described the genetic contribution from wild animals as extraordinary. After one female produced more than 20 million eggs, she said, “It’s amazing to have this much more genetic material added to our captive population.”


On November 18, 2019, scientific divers headed into Southern California waters carrying hundreds of juvenile white abalone raised in captivity. It marked the first time endangered white abalone had been released into the wild as part of the recovery effort. The hope was simple but ambitious: the young animals would survive, grow and eventually establish self-sustaining populations.

Years Later, Scientists Found a Hopeful Sign

The species remains in danger, but the story continues. In May 2026, scientists surveying Channel Islands National Marine Sanctuary discovered a live wild white abalone, the first spotted there in five years. NOAA says the species' population has fallen by an estimated 99% since the 1970s. One sighting does not mean recovery has been achieved. But the decades-long effort shows what conservation can look like when preventing extinction requires more than simply protecting what remains. Scientists have had to breed, raise, treat and physically return a new generation to the sea, giving an animal pushed close to disappearance another chance to reproduce in the waters it once called home.