Azaspiracid accumulation, detoxification and biotransformation in blue mussels (Mytilus edulis) experimentally fed Azadinium spinosum

► Azadinium spinosum was cultured and fed to blue mussels (Mytilus edulis). ► Mussels accumulated azaspiracids in less than 6 h to greater than legal limit. ► Biotransformation of algal toxins into shellfish metabolites was also rapid with >25% metabolites observed after 6 h. ► Detoxification speed was comparable with other lipophilic toxins (half-life ca. 11 days). ► Azaspiracids-6, -17 and -19 should also be considered in legislation.