Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8295
Title: Characterizing toxic activity from Heterosigma akashiwo: a tale of two assays
Author: Vera L. Trainer, Leslie Moore, B.-T. Le Eberhart, Brian D. Bill, W. P. Cochlan, M. L. Wells, J. P. Incardona, T. L. Linbo, C. G. Trick
Publication Year: 2015
Journal: Proceedings of the 16th International Conference on Harmful Algae
Keywords: Heterosigma akashiwo,raphidophyte,toxicity,fish kill,Zebrafish,gill cell assay,

Blooms of the raphidophyte, Heterosigma akashiwo Hada (Sournia) have caused severe economic damage to fish farms in the inland waterways of Washington State, USA, and British Columbia, Canada and are believed to be increasing in frequency and severity. In our study, two laboratory tests were used to characterize H. akashiwo toxicity - a modified rainbow trout gill cell assay and embryonic and larval zebrafish exposures. The gill assay demonstrated that the H. akashiwo toxin is primarily intracellular, highly soluble in methanol and ethyl acetate, and pH stable, with no loss of activity upon storage at -20oC. Stationary phase extracts from H. akashiwo culture were used to characterize the toxin’s specific cellular targets on the development of zebrafish. At 48-hour postfertilization (hpf), intrinsic and specific effects to cardiomyocytes included reduced heart rate and atrial dilation, leading to pericardial edema. Zebrafish heart chambers formed normally, suggesting that the H. akashiwo toxin does not affect early cardiac development but is a physiological poison. In summary, the non-labile toxin from H. akashiwo is a largely intracellular, polar organic compound that causes impairment of cardiac function in fish, possibly through impacts on cellular Ca2+ homeostasis.


Characterization of toxic activity from Heterosigma akashiwo

Theme: Sustainable, safe and secure seafood for healthy populations and vibrant communities
Foci: Provide scientific support to ensure safe seafood for healthy populations and characterize how human activities and climate affect risks from pathogens, chemical contaminants and biotoxins