Bringing Black Abalone Back to California's Mainland From the Channel Islands

National parks shelter species that struggle in developed landscapes — even in the ocean. Since the mid-20th century, California's coast has filled with millions of people. Before that, its rocky shores belonged to another species: black abalone (Haliotis cracherodii). Anyone who grew up on the coast then will tell you that on any visit to the rocks you would find black abalone — lots of them.

Black abalone once dominated California's rocky shores. Image from the National Park Service / Michael Ready

From "inexhaustible" to endangered

Black abalone are a keystone species of the rocky intertidal zone: they play a major part in the health of the ecosystem. They were also long an important food for people.

Mainland populations all but vanished, and remain so today.

A refuge in the islands

Small pockets survived. Isolated and protected, Channel Islands National Park let black abalone ride out overfishing and disease — helped by the islands' cold waters, which are known to limit the spread of withering foot syndrome. Numbers there slowly grew, and are now the highest seen in many years. Still far below the past, but enough that marine ecologists think part of the islands' population can be moved to the mainland, where black abalone have been missing for decades.

The trial move

In 2023, a team from the National Oceanic and Atmospheric Administration, the National Park Service, The Nature Conservancy, the California Department of Fish & Wildlife, and the University of California, Santa Cruz and Santa Barbara began moving 100 black abalone from the Channel Islands to the Central California mainland.

• For a year, the team will track each animal to see whether the move works.
• If it does, another 100–200 will join them, aiming for a lasting, self-sustaining mainland population.

The park service's Southern California Research Learning Center is backing the effort by helping develop eDNA monitoring, which can reveal hard-to-see species like black abalone from genetic material they shed into the water. With partners, it is also documenting the species' journey and the partnerships needed to bring it back.

Sources

Based on "Could Black Abalone Return En Masse to the California Coast? With a Trial Translocation from the Channel Islands, Scientists Hope So," a publication of the Southern California Research Learning Center, National Park Service; a work of the United States government in the public domain. The source credits the 2009 listing to the U.S. Fish and Wildlife Service while linking to NOAA Fisheries' listing page, so the agency is not named.