Algal toxins and producers in the marine waters of Qatar, Arabian Gulf

•Two cruises were performed in 2012 and 2013 in the Arabian Gulf, east of Qatar.•Phytoplankton were analyzed for 5 algal toxin groups with LC-MS/MS and ELISA.•First report of PSTs, DST, AST, cyclic imines and polyether-lactone toxins.•Vulcanodinium rugosum was observed for the first time in the Arabian Gulf.•V. rugosum cultures produced pinnatoxin H and portimine.

Harmful Algal Bloom species are ubiquitous and their blooms occur in the Arabian Gulf. In this study, two cruises were performed in 2012 and 2013 to collect phytoplankton samples from 4 sites in the Arabian Gulf. Toxin analyses of phytoplankton samples for 32 algal toxins from 5 different toxin groups were conducted on the samples using both enzyme linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results demonstrated, for the first time, the presence of paralytic shellfish toxins (PSTs), diarrhetic shellfish toxin (DST), amnesic shellfish toxin (AST), cyclic imines (CIs) and polyether-lactone toxins in freeze-dried phytoplankton samples. Four Vulcanodinium rugosum cultures were established from field samples and these proved to contain between 603 and 981 ng pinnatoxin (PnTx) H per mg dry weight in addition to being positive for portimine. These strains from Qatar clustered with strains from Japan and Florida based on large subunit rRNA and rRNA internal transcribed spacer gene sequences.