White Abalone
White Abalone
Haliotis sorenseni
Quick Facts
Weight
About 1.7 pounds
Length
Up to 10 inches
Lifespan
Up to 40 years
Threats
Disease,
Historical overfishing,
Low reproduction rates
Region
West Coast
White abalone. Credit: NOAA Fisheries
White abalone. Credit: NOAA Fisheries
About the Species
The white abalone belongs to a group of plant-eating marine snails that were once common in California. They once numbered in the millions off the California coast, but now they are endangered.
Before the time of commercial fisheries, native people along California’s coast ate abalone for thousands of years. Large groups of abalone shells indicating human settlement, or “middens,” date back 7,400 years. Abalone shells were also traded along routes starting in southern California and reaching east of the Mississippi River.
White abalone continue to live in the coastal waters of Southern California and Mexico. They are “broadcast spawners,” releasing eggs and sperm into the water by the millions when environmental conditions are right. Their strong, muscular “foot” allows them to hold tightly to rocks and other hard surfaces while their oval-shaped shells protect them from predators. Although fishing for white abalone has been illegal in California since 1997, the high price of abalone meat makes them a target of poachers.
White abalone were listed as endangered under the Endangered Species Act in 2001, and were the first marine invertebrate to be listed. White abalone are one of NOAA Fisheries' Species in the Spotlight—an initiative that includes animals considered most at risk for extinction and prioritizes their recovery efforts. The black abalone is also listed as endangered under the ESA.
NOAA Fisheries is dedicated to conserving and restoring white abalone. Our scientists use innovative techniques to study, protect, and restore their population. We also work with our partners to ensure that regulations and management plans are in place to reduce poaching and increase the wild abalone population.
Population Status
Commercial fishing has severely reduced white abalone numbers from historical levels. Surveys in southern California show a 99 percent decrease in the number of white abalone since the 1970s. While there were once millions, the current population is about 1,600 to 2,500 individuals. One well-studied population of white abalone in southern California decreased by about 78 percent between 2002 and 2010 (from about 15,000 individuals to just 3,000).
California’s closure of the white abalone fishery in 1997 may have slowed the animals’ decline, but likely not by enough to recover the population. The species now faces threats from low breeding rates and disease. For example, if that well-studied population in southern California is left alone, it will likely continue to decrease by about 10 percent per year.
But, while white abalone are close to extinction, efforts to breed them in captivity and reintroduce them to the wild could help the species recover.
Protected Status
ESA Endangered
- Throughout Its Range
Appearance
White abalone have a thin, oval-shaped shell. The shell has a row of holes used to breathe, remove waste, and reproduce. The bottom of its foot—the muscle it uses to move and adhere to rocks—is orange. It also has a tan-orange epipodium, an extension of the foot with tentacles used to sense the surrounding environment.
Biology
Abalone are slow-moving bottom dwellers. They attach to rocks and other hard surfaces using their muscular foot and, when disturbed, they become difficult or impossible to remove. An abalone can also use its foot to move across surfaces.
Adults eat different types of algae. They can catch kelp drifting along the seabed or eat kelp still attached to rocks. The reddish-brown color of their shells shows that white abalone eat some types of red algae throughout their lives.
Where They Live
Range
White abalone live on rocky substrates alongside sand channels, which tend to accumulate the algae they eat. They are usually found at depths of 50 to 180 feet, making them the deepest living abalone species. Historically, white abalone were found in the Pacific Ocean from Point Conception, California, to Punta Abreojos, Baja California, in Mexico. In California, they were most abundant at offshore islands (especially San Clemente and Santa Catalina Islands) and submerged banks (primarily Tanner and Cortes Banks). At the southern end of the range in Baja California, white abalone were often reported along the mainland coast, but were also found at many islands, including Isla Cedros, Isla Natividad, and Isla Guadalupe. Today, researchers have found extremely low numbers of white abalone along the mainland coast of southern California, and at a few of the offshore islands and banks. The status of the species in Mexico remains largely unknown. While there is little or no recent information from Baja California, commercial fishery data suggest that the population there is also depleted.
World map providing approximate representation of the white abalone's range.
Scientific Classification
White abalone live on rocky substrates alongside sand channels, which tend to accumulate the algae they eat. They are usually found at depths of 50 to 180 feet, making them the deepest living abalone species. Historically, white abalone were found in the Pacific Ocean from Point Conception, California, to Punta Abreojos, Baja California, in Mexico. In California, they were most abundant at offshore islands (especially San Clemente and Santa Catalina Islands) and submerged banks (primarily Tanner and Cortes Banks). At the southern end of the range in Baja California, white abalone were often reported along the mainland coast, but were also found at many islands, including Isla Cedros, Isla Natividad, and Isla Guadalupe. Today, researchers have found extremely low numbers of white abalone along the mainland coast of southern California, and at a few of the offshore islands and banks. The status of the species in Mexico remains largely unknown. While there is little or no recent information from Baja California, commercial fishery data suggest that the population there is also depleted.
| Kingdom | Animalia | Phylum | Mollusca | Class | Gastropoda | Order | Archaeogastropoda | Family | Haliotidae | Genus | Haliotis | Species | sorenseni |
|---|
Featured News
Veteran Damon Jackson (left), a NOAA intern in Portland, Oregon, visits a restoration project on the Willamette River. Credit: NOAA
Construction underway to restore fish passage on the Little Tonsina River. Credit: Copper River Watershed Project.
Cook Inlet beluga whale
The Pacific leatherback sea turtles have existed in their current form without scales and a hard shell since the age of the dinosaurs, but threats from bycatch, egg harvesting, and degradation of nesting habit have made this species endangered. Photo credit Jason Isley, Scubazoo.
Related Species
Seafood Facts
Seafood News
Rainbow in the dusk sky at San Diego Harbor. Credit: NOAA/Liana Heberer.
The NOAA Aquaculture Strategic Plan (2023–2028) includes goals and objectives to sustainably develop the aquaculture industry in the United States. Credit: NOAA Aquaculture Program
Raw oysters on plate. Credit: NOAA Fisheries.
Science Overview
NOAA Fisheries conducts research on the biology, behavior, and ecology of the white abalone. The results are used to inform management decisions and enhance recovery efforts for this species.
Along with NOAA Fisheries, many groups—both in the United States and in other countries—are working to help save the white abalone. Among them are Channel Islands National Park, the California Department of Fish and Game, and El Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE; Baja California, Mexico).
Image
White Abalone Restoration Consortium
The White Abalone Restoration Consortium is made up of many groups, all working towards expanding scientific knowledge of white abalone and increasing public awareness. Scientists, fishermen, conservation organizations, universities, federal and state agencies, and private organizations are working together to:
- Locate white abalone in the wild by surveying their natural habitat.
- Collect abalone from the wild to support a captive breeding program.
- Breed and raise new generations of young abalone.
- Enhance populations of white abalone that can reproduce on their own in the wild.
Habitat Surveys
Our scientists are working to learn more about which habitats are best suited to white abalone. We use remotely operated vehicles, SCUBA, seabed-mapping sonars, and computer models to study abalone habitats in great detail. Those details let us narrow down the wide variety of habitat features important to white abalone. We also collect information on general habitat features like depth and algal types, which could help predict the presence of white abalone in unexplored areas. These surveys help ensure that conservation efforts focus on areas most likely to support healthy white abalone populations.