Increase in records of toxic phytoplankton and associated toxins in water samples in the Patagonian Shelf (Argentina) over 40 years of field surveys

•Records of toxin-producing microalgae and phycotoxins have risen over four decades.•The monitored area has expanded from coast to mid-shelf and shelf-break front (SBF).•Scientific interest (ecophysiology/biogeography) has intensified monitoring efforts.•Pectenotoxins and saxitoxins are the most documented and widespread toxins in the Argentine Sea.•Highly abundant blooms of Amphidomataceae (azaspiracid producers) occur along the SBF.