From lipophilic to hydrophilic toxin producers: Phytoplankton succession driven by an atmospheric river in western Patagonia

Phytoplankton succession is related to hydroclimatic conditions. In this study we provide the first description of a toxic phytoplankton succession in the Patagonian Fjord System. The shift was modulated by atmospheric-oceanographic forcing and consisted of the replacement of the marine dinoflagellate Dinophysis acuta in a highly stratified water column during austral summer by the diatom Pseudo-nitzschia calliantha in a mixed water column during late summer and early autumn. This transition, accompanied by a change in the biotoxin profiles (from lipophilic dinophysis toxins to hydrophilic domoic acid), was induced by the arrival of an intense atmospheric river. The winds in Magdalena Sound may have been further amplified, due to its west-east orientation and its location within a tall, narrow mountain canyon. This work also documents the first known appearance of toxic P. calliantha in Northern Patagonian. The potential impacts of the biotoxins of this species on higher trophic levels are discussed.

This study was funded by projects REDI170575 and REDES170101 from the International Cooperation Programme of ANID and partly supported by the Helmholtz-Gemeinschaft Deutscher Forschungszentren through the research program “Changing Earth - Sustaining our Future” of the Alfred Wegener Institut (AWI)-Helmholtz Zentrum für Polar- und Meeresforschung. The authors thank Annegret Müller (AWI) for sample processing and Thomas Max (AWI) for LC-MS/MS measurements. P.A. Díaz was funded by FONDECYT-ANID 11170682 and by the Centre for Biotechnology and Bioengineering (CeBiB) (PIA project FB0001, ANID, Chile). G. Álvarez was funded by FONDEF/CONICYT 2017, IT17F10002. Iván Perez-Santos was funded by COPAS Sur-Austral (ANID AFB170006), COPAS COASTAL (ANID FB210021), CIEP R20F002, and FONDECYT 1211037. Rosa I. Figueroa was funded by a national project from the Spanish Ministry of Science and Innovation and the European Community, European Regional Development Fund (ERDF; Project BIOTOX PID2021-1256430B-C22). René Garreaud was supported by ANID Fondecyt Regular Grant 1211412 and ANID FONDAP 1522A0001. Marco Pinto-Torres was funded by scholarship Program DOCTORADO 2016 - Folio Number 21160047.

Peer reviewed