Abstract

Amnesic Shellfish Poison (ASP), domoic acid, is one of the toxins that have been monitored in the Magellan region (48°-55°S southern Chile) by LC-FL in at least 43 stations over the last 15 years. The levels have always been in the range of non-detectable or traces. However, in 2015, for the first time, toxin levels close to detection limit were found in ribbed mussels (Aulacomya ater - 19.75 μg g-1), from a monitoring station (49°46’S, 74°19’W). During the following months, these levels were again not detectable in the same species and sampling location. A fortnight after and on samples from a more oceanic area (50°20’ S, 75°21’ W), ASP was detected at sub-toxic levels by LC-FL and LC-MS in the fractionated plankton (20-200 μm), ribbed (A. ater) and blue (Mytilus chilensis) mussels (0.74 and 1.52 μg g-1, respectively). ASP is common in low latitudes (27°S) and in the south of Chile (41°- 46° S) is generally associated with scallop or blue mussel farms, respectively. The discovery of ASP in places with little or no human influence as the sub-Antartic channels, lead to concluded that 2015-2016 period was not only the PSP and dinoflagellates year at the Chilean coast, but indicates that diatoms were apparently also involved in HABs events during spring. However, such events virtually were undetected in the coast adjacent to Pacific Ocean of the Magellan region due to difficult access to oceanic areas and the low sampling frequency.