Essential knowledge for black abalone recovery efforts: Long-term monitoring and research gives us the ability to forecast impending population crashes and species’ vulnerabilities to pressures.
Cluster of live black abalone Haliotis cracherodii in Big Sur. This is how healthy populations appear. Photo credit: Steve Lonhart / NOAA MBNMS
In 2009 black abalone were listed as an endangered species. Their current range is from about Point Arena in northern California to Southern Baja California. Black abalone are rare north of San Francisco and south of Punta Eugenia, Baja with unconfirmed sightings reported as far north as Coos Bay, Oregon.
The black abalone fishery (Haliotis cracherodii) was closed in 1993 because of massive population declines from a fatal disease called withering syndrome (WS) combined with fishing pressure. WS is devastating. Once die-offs begin, the local population often decreases by more than 95%, leaving only a scattering of individuals typically too distant from one another to successfully reproduce. The die-offs began in Southern California and moved northward, exploding during El Nino years when the ocean water is warmer.
With more than two decades of data and understanding of the abalone’s ecology, PISCO scientists and collaborators documented these historical population declines and projected bleak outlooks for recovery. In 2009 based in part on these studies, black abalone were added to the federal list of endangered species. This listing means that the black abalone faces a high risk of extinction. Various projects are now in place to monitor the species status, understand and address withering disease, improve reproduction, and minimize illegal harvest.
PISCO scientist Pete Raimondi leads these PISCO investigations on the long-term monitoring and suitable habitat assessments for the recovery effort.
Funders for this work are: the David and Lucile Packard Foundation (for support of PISCO's rocky intertidal monitoring and research program), U.S. Bureau of Ocean Energy Management (for the Multi-Agency Rocky Intertidal Network), National Marine Fisheries Service (for monitoring in critical habitat areas), U.S. National Park, and the US Navy (for San Clemente Island).
For more information, visit Pacific Rocky Intertidal Monitoring: Trends and Synthesis