Why Black Abalone? California's Toughest, Most Overlooked Abalone

An overlooked snail

Black abalone are endangered marine snails living in tidepools along California and Baja California, and their history is bound up with the state's human history. The Point Reyes podcast The Natural Laboratory devotes two episodes to them. Its producer, asked "Why black abalone?", explains here what makes them a case study in balance — between land and sea, ancient and modern, vulnerability and resilience.

Seven species, all in trouble

California has seven abalone species, living at different depths:

• Black and white abalone are federally endangered, devastated by decades of overharvesting and by disease.
• Green, pink, pinto and flat abalone are species of concern.
• The red abalone fishery was closed from 2017 through 2026 to let it recover.

Why no one remembers black abalone

Coastal Californians light up at the word abalone: shells lining fences from when they were plentiful, earrings carved from mother-of-pearl, family stories of diving. A Point Reyes park ranger grew up on their parents' diving stories and free-dove for red abalone as a teenager before the 2017 closure.

But nearly all those memories are of red abalone. Black abalone — the only species living mainly in tidepools, the most accessible sea habitat of all — are smaller, with tougher meat and less valuable shells, as Ann Vileisis explains in Abalone: The Remarkable History and Uncertain Future of California's Iconic Shellfish. Only when red and other abalone declined in the 1970s did people turn to black abalone — and overharvest them too.

They are still overlooked. White abalone drew attention in 2022 for a breakthrough at UC Davis's Bodega Marine Laboratory, where ultrasound helped captive breeding. Black abalone are the only California species not yet spawned in captivity — though the ultrasound research was first funded to help them, and its researchers hope it will.

Built for the hardest place in the sea

Other abalone prefer the calmer seafloor. Black abalone have lived for millions of years in the intertidal zone, which Rachel Carson called "the primeval meeting place of the elements of earth and water, a place of compromise and conflict and eternal change." They must survive:

• blistering sun and smashing waves;
• predators from land and sea;
• waiting for the rising tide to bring food, and the falling tide to carry their eggs and sperm away.

According to Susan Wang of NOAA and Pete Raimondi of UC Santa Cruz, black abalone are far more resilient than other sea life to warming and to changes in pH and oxygen. That toughness may even be why they will not spawn in a lab: the simple cues that work for other abalone may not be enough for them.

Disease

Resilience did not protect them from a subtler threat. In 1983, a record El Niño carried a new bacterium into Southern California waters, bringing withering syndrome. At Channel Islands National Park it killed 99% of black abalone, according to marine ecologist Steve Whitaker — where scientists had found them stacked four or five deep a few years earlier, they could not find one. For thirty years researchers and policymakers have worked on rescue.

A comeback?

A few years ago, black abalone began rebounding exponentially at some Channel Islands sites. The leading theory is that a virus that infects bacteria (a phage) is consuming the bacterium behind withering syndrome — though the abalone's own tenacity may help too. Full recovery across Southern California will take much more work. The hope: that visitors to California tidepools will one day see the blue-black shells and think not "What are those?" but "There they are again at last."

Learn more

• The Natural Laboratory podcast episodes on black abalone, Point Reyes National Seashore
• Ann Vileisis, Abalone
• Jacquelyn Ross, "Holding Fast for Abalone, Our Elder Relatives," Bay Nature
• Wudan Yan, "Researchers See 'Future of an Entire Species' in Ultrasound Technique," New York Times
• Rosanna Xia, "Can the Long-Lost Abalone Make a Comeback in California?," Los Angeles Times
• Dominick Leskiw, "Holding Fast, or Failing?," Earth Island Journal
• Kenan Chan, "Fires, mud, and abalone," Oceanographic

Sources

Based on Theodora Mautz, "“Why Black Abalone?”: The Duality of Black Abalone in California," Bay Area Nature & Science Blog, Point Reyes National Seashore Association and National Park Service; published by the National Park Service. The article's photographs and its depth diagram, credited to partners and individuals, are not reproduced.