THE OCCURRENCE OF PHYCOTOXINS IN COASTAL AREAS OF SOUTH AMERICA

KROCK, BERND; TILLMANN, URBAN; TREFAULT, NICOLE; LOVRICH, GA; BOREL, MARCELA

Baiona

Workshop; 4th Joint symposium and AOAC task force meeting Baiona; 2013

According to climate change scenarios it is likely that plankton including HAB species may extend their distributional range from temperate waters, where they are known to occur, into colder high latitudes and even polar regions. Indeed initial reports hint in this direction, and thereby effects on shellfish harvesting and management of toxins in these formerly pristine areas are to be expected. In order to study this emerging phenomenon we conducted several field surveys of plankton and associated toxins in the south east Pacific and the southwest Atlantic. The first expedition was carried out along the Chilean coast line between latitudes 55°S and 27°S in March 2009. The second survey was carried out in the fjords of Tierra del Fuego between latitudes 55°S and 52.5°S in October/November 2010. A third expedition was conducted in Argentinean shelf waters between latitudes 38°S and 56°S in March/April 2012. During all campaigns plankton was sampled either by phytoplankton net (20 µm mesh) vertical hauls with subsequent size-fractionation or water pumping, and by filtration of Niskin bottle water samples from discrete depths. In addition, sediment samples at selected stations were taken on the Argentinean transect with Van Veen grab samplers for collection of dinoflagellate cysts. Plankton sample aliquots were split and extracted for hydrophilic paralytic shellfish poisoning (PSP) toxins and the amnesic shellfish poisoning (ASP) toxin domoic acid, and for lipophilic phycotoxins, including the cyclic imine toxins gymnodimines and spirolides, the polyether toxins okadaic acid and dinophysistoxins causing diarrhetic shellfish poisoning (DSP), as well as for pectenotoxins, yessotoxins and azaspiracids. The PSP toxins were analysed by liquid chromatography with post-column derivatization and fluorescence detection (LC-FD), whereas all other toxins were analysed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The occurrence of phycotoxins in plankton will be presented.