Abstract: Unusually high concentrations of the neurotoxin domoic acid (DA) were detected in a minke whale (Balaenoptera acutorostrata) carcass recovered during a severe harmful algal bloom (HAB), which occurred in southern California in April 2007. Cell fragments of the toxigenic diatom Pseudo-nitzschia australis were observed in whale gastric fluid and feces, corresponding to a dominance of Pseudo-nitzschia spp. in the phytoplankton com-munity at the time of stranding. A high abundance of otoliths from a prominent DA vector, the northern anchovy (Engraulis mordax), were recovered in whale stomach contents, indicating trophic transfer of DA via the food web. Whale feces contained 258 µg DA per gram sample, exceeding DA concentrations reported for any marine mammal. DA intoxication was identified as the cause of mortality of this animal, expanding on the limited understanding of the impacts of DA-producing HABs on large whales.

Key Words: domoic acid, harmful algal bloom, algal toxin, stranding, marine mammal, minke whale, Balaenoptera acutorostrata

Document Type: Research article

DOI: 10.1578/AM.36.4.2010.342

Page Numbers: 342-350