Toxigenic phytoplankton and concomitant toxicity in the mussel Choromytilus meridionalis off the west coast of South Africa

摘要: Abstract The variability of toxigenic phytoplankton and the consequent uptake loss toxins by mussel Choromytilus meridionalis was investigated in southern Benguela at event scale (3–10 days) response to upwelling–downwelling cycle. Phytoplankton samples were collected daily (20 March–11 April 2007) from a mooring station (32.04°S; 18.26°E) located 3.5 km offshore Lambert's Bay, within St Helena Bay region. Rapid changes assemblages incorporated three groups phytoplankton: (1) dinoflagellate Alexandrium catenella ; (2) several species Dinophysis , including acuminata fortii hastata rotundata (3) members diatom genus Pseudo-nitzschia . Analysis concentrates LC–MS/MS or LC-FD provided information on toxin composition calculated toxicity each group. Several additional vitro assays used for analysis mussels (ELISA, RBA, MBA PSP toxins; ELISA DSP toxins). Good correspondence observed between methods except MBA, which significantly lower (approximately 2-fold) estimates toxins. both exceeded regulatory limits Choromytilis but ASP undetected. Differences C. that ingested dinoflagellates (PSP showed an increase STX, C1,2, traces dcSTX GTX1,4 decrease NEO; increased DTX1, PTX2sa, OA). rate following dispersal A. boom 0.12 d −1 Variation rates different contributed change profile Prediction net shellfish nearshore environment is limited due rapid community changes, high cellular toxicity, selective toxins, and/or transformation