CRCritically Endangered

Haliotis walallensis

Haliotis walallensis, commonly known as the Walalla abalone, is a marine gastropod mollusk endemic to the coastal waters of the Pacific Northwest. This species belongs to the family Haliotidae, characterized by its distinctive ear-shaped shell with a series of respiratory holes along the outer edge.

Decreasing

Population trend

3

Countries

01Classification

Taxonomy & Classification

Kingdom

ANIMALIA

Phylum

MOLLUSCA

Class

GASTROPODA

Order

LEPETELLIDA

Family

HALIOTIDAE

Genus

Haliotis

Haliotis walallensis belongs to the family HALIOTIDAE, order LEPETELLIDA, within the GASTROPODA class.

02Description

Species Profile

Haliotis walallensis, commonly known as the Walalla abalone, is a marine gastropod mollusk endemic to the coastal waters of the Pacific Northwest. This species belongs to the family Haliotidae, characterized by its distinctive ear-shaped shell with a series of respiratory holes along the outer edge. The Walalla abalone inhabits rocky intertidal and subtidal zones, typically found attached to hard substrates in areas with strong water circulation and abundant kelp forests. These mollusks are herbivorous, feeding primarily on various species of marine algae and kelp. The species has experienced severe population declines due to multiple anthropogenic pressures. Overharvesting for commercial and recreational purposes has significantly reduced wild populations, while habitat degradation from coastal development and pollution has further compromised remaining populations. Climate change impacts, including ocean acidification and rising sea temperatures, pose additional threats to shell formation and overall survival. Disease outbreaks, particularly withering syndrome caused by bacterial infections, have devastated many abalone populations along the Pacific coast. Conservation efforts include strict harvest regulations, habitat protection measures, and captive breeding programs aimed at population recovery. Marine protected areas have been established in critical habitat zones, and restoration projects focus on kelp forest conservation. Research continues into disease management and genetic diversity preservation to support long-term species recovery. Despite these efforts, the species remains critically endangered with continued population decline.

The Walalla abalone faces severe threats from historical overharvesting, habitat loss due to coastal development, and ongoing impacts from climate change including ocean acidification. Disease outbreaks, particularly withering syndrome, have caused significant mortality in remaining populations. Degradation of kelp forest ecosystems, which provide essential food sources, further compromises the species' survival prospects.

Key Facts

IUCN StatusCritically Endangered (CR)
TrendDecreasing
GroupMolluscs
03Habitat

Habitat & Distribution

Haliotis walallensis inhabits rocky intertidal and shallow subtidal zones along the Pacific Northwest coast, typically attaching to hard substrates in areas with strong water circulation. The species depends on healthy kelp forest ecosystems that provide both food resources and shelter from predators and wave action.

Marine neriticMajor
04Threats

Threats

!

IUCN Red List: Critically Endangered

The Walalla abalone faces severe threats from historical overharvesting, habitat loss due to coastal development, and ongoing impacts from climate change including ocean acidification. Disease outbreaks, particularly withering syndrome, have caused significant mortality in remaining populations. Degradation of kelp forest ecosystems, which provide essential food sources, further compromises the species' survival prospects.

Fishing & harvesting aquatic resources

Ongoing

Habitat shifting & alteration

Ongoing

Hunting & trapping terrestrial animals

Ongoing

Invasive non-native/alien species/diseases

Ongoing

Livestock farming & ranching

Ongoing

Marine & freshwater aquaculture

Ongoing

Problematic native species/diseases

Ongoing

Temperature extremes

Ongoing
05Conservation

Conservation Actions

Habitat & natural process restoration
Species management
Species recovery
Ex-situ conservation
Legislation
06Range

Found in 3 Countries

Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

This page: SpeciesRadar (2025). Haliotis walallensis (Haliotis walallensis). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/flat-abalone

Full citation guide & data usage terms