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 attach 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.
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. 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.
- Throughout Its Range
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 a muscle it uses to move and attach to rocks—is orange. It also has a tan-orange epipodium, an extension of the foot with tentacles used to sense the surrounding environment.
Behavior and Diet
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 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
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.
Lifespan & Reproduction
White abalone live about 35 to 40 years. Adults become sexually mature in the wild when they are four to six years old.
Abalone reproduce by broadcast spawning—releasing their eggs and sperm into the water. The eggs hatch after only one day if fertilized, but large amounts of sperm are needed to fertilize an egg. This means fertilization succeeds more often when groups of adult male and female abalone are close to each other when they spawn. Fertilized eggs hatch into larvae, which later grow into adults.
Due to their unique mating habits, white abalone can be depleted by intense fishing that targets groups of animals.
A commercial abalone fishery opened in California in the early 1970s, peaked in the mid-1970s, and closed in the 1980s. The fishery used size limits and seasons to reduce the number of abalone caught. Even with these protections, the fishery greatly decreased the abalone populations and has had long-term effects on their recovery.
Low Reproduction Rates
The most significant threat to white abalone recovery is low reproduction rates.
One female abalone can release as many as 10 million eggs at a time—but unless the eggs come in contact with sperm from spawning males, they cannot be fertilized. With their low population, abalone are often found alone, without potential mates nearby. This makes spawning in the wild unlikely or impossible.
Wild abalone have produced few offspring since the late 1960s/early 1970s. Studies have found that abalone mortality exceeds reproduction in the wild. In a study from 2000 (PDF, 1.8MB), scientists estimated that the remaining wild white abalone would disappear by 2010 without help from humans.
Abalone are also threatened by disease. Withering syndrome, one common type of infection, is a fatal disease that affects the digestive organs of abalone. The pathogen that causes it is currently present in the coastal oceans of southern California. No wild white abalone have been found to have the fatal symptoms of withering syndrome, but captive abalone have died from the disease and wild white abalone are known to carry the pathogen that causes it. Although disease was not a threat to abalone in the past, withering syndrome now threatens the recovery of this species.
In the Spotlight
The white abalone is one of NOAA Fisheries’ Species in the Spotlight. This initiative is a concerted, agency-wide effort to spotlight and save the most highly at-risk marine species.
White abalone are plant-eating gastropods (similar to snails and slugs) that live on rocky parts of the sea floor. Of the seven species of abalone that occur off the West Coast of North America, white abalone are the closest to extinction.
White abalone were once common along the coasts of California and Baja California, Mexico, but the population has declined rapidly. This decline was largely due to the operation of a brief, but intense commercial fishery in southern California during the 1970s. All abalone fisheries have been closed since 1997, but unfortunately the white abalone populations have not recovered as expected.
NOAA Fisheries listed white abalone as endangered under the Endangered Species Act in 2001. The rapid decline and dire status of the white abalone population makes it a priority for focusing efforts within NOAA Fisheries and with our partners to stabilize and prevent the extinction of this unique species.
To aid the recovery of white abalone, NOAA Fisheries formed a team of scientists and stakeholders to assist with developing a white abalone recovery plan (PDF, 948KB) which was finalized in October 2008. Development of the plan relied upon scientific studies and other sources of information to establish specific criteria that would indicate the recovery of these animals.
In 2016, we completed a Species in the Spotlight 5-year Plan of Action for white abalone that builds on the recovery plan and details the focused efforts that are needed over the next five years. The plan lists key actions NOAA Fisheries and its partners can take from 2016 to 2020 to help recover the species. These actions include:
Improve and expand the captive breeding program.
Implement a program to successfully introduce captive-bred abalone to the wild.
Monitor and enhance white abalone populations in the wild.
Find, describe, and protect white abalone habitat.
Work with partners to develop a collaborative outreach plan.
These actions will help NOAA Fisheries, other federal and state resource agencies, environmental organizations, and other partners to stop the decline of white abalone and promote their recovery.
White abalone are protected under the Endangered Species Act. NOAA Fisheries has dedicated significant resources to monitoring and rebuilding their populations. We have developed a captive breeding program and routinely monitor the status and habitats of wild abalone in California.
Recovery Planning and Implementation
The ESA requires NOAA Fisheries to develop and implement recovery plans for the conservation and survival of listed species. Our plan for white abalone seeks to help them thrive, allowing them to be reclassified from “endangered” to “threatened” and ultimately removed from the list of protected species.
The plan recommends five major actions:
Monitor populations and their habitat in the wild.
Protect populations and their habitat in the wild.
Use a captive breeding program to enhance wild populations.
Develop an enforcement, public outreach, and education plan.
Get financial support for white abalone recovery.
Together with our partners, we undertake many activities to support the goals of the white abalone plan. The goal is to increase the wild white abalone populations in California and Mexico to self-sustaining levels.
Efforts to conserve white abalone include:
A captive breeding program.
Monitoring the wild population and its habitat use.
Public outreach and education.
Captive Breeding Program
NOAA Fisheries and its partners have developed a captive breeding program to produce young abalone that can be reintroduced into the wild, in hopes to protect white abalone from extinction. NOAA Fisheries has developed a guide that allows public and private organizations to participate in captive breeding programs and receive federal funding for their efforts. Our West Coast Region implements the captive breeding program in close partnership with the University of California at Davis’ Bodega Marine Laboratory and in partnership with five other facilities throughout California.
Once the captive-bred abalone are old enough, researchers will release them into the wild. These captive-bred abalone will grow and become a part of the remaining wild population, where they will hopefully improve the spawning success and be incorporated into healthy, self-sustaining populations.
The Bodega Marine Laboratory oversees the captive breeding program. Its first successful spawning attempt in more than a decade occurred in 2012 at the Aquarium of the Pacific and at the University of California, Santa Barbara. The program has successfully raised white abalone and increased the number of individuals raised in captivity each year since 2012.
Captive breeding efforts by current and future partners are expected to produce hundreds of thousands of animals that are ready to be reintroduced to the wild over the next 5 to 15 years. NOAA Fisheries is working closely with its partners to reduce disease risks for captive-bred abalone and to develop tools for increasing the survival of captive-bred abalone once reintroduced to the wild.
Monitoring the Wild Population
Researchers monitor wild white abalone habitats to track population trends over time. We work with our partners on the monitoring program in southern California. These surveys help us assess the recovery of wild white abalone populations and will help us determine whether our captive breeding program is working.
We monitor the distribution, abundance, and behavior of white abalone using remotely-operated vehicles (ROVs), SCUBA, acoustic telemetry, and time lapse cameras. We steadily improve our methods for surveying populations and studying their movements, and are developing genetic techniques to track individual animals. We are also helping abalone health specialists monitor for the pathogen that causes withering syndrome in southern California waters and study the risks that healthy abalone face when they come in contact with the pathogen.
Continuing and expanding our monitoring program will help the species by:
Providing data needed to measure long-term population trends.
Finding signs of disease so that we can avoid mortality in the captive breeding program.
Developing tools to identify white abalone in the wild and determine whether they are captive-bred or wild-bred.
Understanding factors that affects white abalone survival, growth, and reproduction.
Synthesize available information to improve abalone conservation efforts.
Public Outreach and Education
NOAA provided funding and guidance to create an interactive exhibit about white abalone at the Aquarium of the Pacific. We also supported "Get Inspired," a local non-profit organization, in creating a classroom abalone program and curriculum. Many high school classrooms in Orange County, California currently culture abalone through this program.
Commercial fisheries severely reduced white abalone numbers from historical levels. The state of California closed the white abalone fishery in 1996, then closed all abalone fisheries in central and southern California in 1997. The same year, we designated the white abalone as a candidate for listing under the Endangered Species Act from central California to Baja California, Mexico. The United States listed white abalone as endangered in 2001.
NOAA Fisheries published the White Abalone Recovery Plan in 2008 to identify actions that would protect the species. In addition, we have taken steps to rebuild the population including:
Development of a captive breeding program to reintroduce white abalone into the wild.
Monitoring wild abalone populations and their habitat use.
In 2016, NOAA Fisheries developed a five-year action plan to build on the existing recovery plan.
Key Actions & Documents
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).
New Spawning Techniques
Scientists are spawning abalone in the laboratory where they have more control over the process. However, laboratory spawning requires scientists to permanently remove abalone, which are already severely depleted, from their natural habitat. To avoid this, scientists are attempting to spawn abalone in the field. In 2014, a group of scientists took abalone from the ocean, separated males and females into buckets filled with seawater on the deck of the boat, and then combined the sperm and eggs from the buckets. The new approach worked: the eggs were fertilized and the abalone were later returned to the ocean.
The overall goal of the white abalone captive breeding program is to produce enough healthy young abalone to release them into the ocean to enhance wild stocks.
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.
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.
Published Date: 2000
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