Demographics and spatio-temporal signature of the biotoxin domoic acid in California sea lion (Zalophus californianus) stranding records

Adriana C. Bejarano, Frances M. Gulland, Tracey Goldstein, Judy St Leger, Michele Hunter, Lori H. Schwacke, Frances M. VanDolah, Teri K. Rowles

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


California sea lions (Zalophus californianus) in otherwise good nutritional condition have been consistently affected by the marine biotoxin domoic acid since the late 1990s. In this study we evaluated the temporal and spatial stranding patterns of suspected and confirmed cases of domoic acid intoxicated sea lions from 1998 to 2006, using records of strandings along the California coast obtained from members of the California Marine Mammal Stranding Network. The majority of domoic acid cases were adult females (47%-82% of the total annual domoic acid cases), a contrast to strandings that were not related to domoic acid, which were generally dominated by juveniles and pups. Exposure to this biotoxin led to a 6.67-fold increase in adult female strandings in 2000, and a 5.44-fold increase in adult female deaths in 2006, relative to strandings and deaths of adult female not affected by domoic acid. Domoic acid cases have occurred annually since 1998 (except for 1999) between April and August, with clusters centered primarily at Pismo Beach (San Luis Obispo County), as well as at other beaches in San Luis Obispo, Monterey, Santa Cruz, Santa Barbara, Orange, and San Diego counties. The larger ecological and population level implications of increased domoic acid strandings and deaths, particularly among adult female sea lions, warrant further attention and need to be investigated.

Original languageEnglish (US)
Pages (from-to)899-912
Number of pages14
JournalMarine Mammal Science
Issue number4
StatePublished - Oct 2008
Externally publishedYes


  • Biotoxin domoic acid
  • California sea lion
  • Stranding patterns
  • Zalophus californianus

ASJC Scopus subject areas

  • Aquatic Science
  • Ecology, Evolution, Behavior and Systematics


Dive into the research topics of 'Demographics and spatio-temporal signature of the biotoxin domoic acid in California sea lion (Zalophus californianus) stranding records'. Together they form a unique fingerprint.

Cite this