Are yessotoxins an emerging problem in Chile? Context and perspectives following the first report of YTX levels exceeding the regulatory limit in the Patagonian fjord system

• Published in: Environmental pollution (1987) 2024-11, Vol.361, p.124844, Article 124844
• Main Authors: Díaz, Patricio A., Araya, Michael, Cantarero, Bárbara, Miranda, Carolina, Varela, Daniel, Figueroa, Rosa I., Basti, Leila, Carbonell, Pamela, Aravena, Álvaro, Pérez-Santos, Iván, Nieves, María Gabriela, Álvarez, Gonzalo
• Format: Article
• Language: English
• Subjects: Fjord system; Mytilus chilensis; Protoceratium reticulatum; Regulatory limit; Yessotoxins
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2024.124844

In late summer and early autumn 2022, an intense bloom of Protoceratium reticulatum—the main yessotoxin (YTX) producer along Chilean coasts and a major threat to artisanal fisheries, the aquaculture industry, and environmental health—was recorded in the Patagonian fjord system. The high YTX levels (>3.75 mg kg−1) resulted in the first ban of shellfish collection in Chile. At Puyuhuapi Fjord, a global "hotspot" of harmful algal bloom events, the cell density of P. reticulatum determined in integrated tube samples (0–10 m) at the end of April 2022 reached 407,000 cells L−1. At the same time, YTX levels well exceeded the regulatory limit by roughly 2.5-fold, with concentrations as high as 9.42 mg kg−1 measured in native populations of the blue mussel Mytilus chilensis. Five different YTX analogues, 45-OH-YTX, COOH-45-keto-YTX, COOH-45-OH-YTX, COOH-YTX, and 45,55-diOH-YTX, were also detected in relevant amounts. While the ban lasted close to 3 months, accumulation and detoxification processes were monitored over a 1-year period. This study assessed the implications of high levels of YTXs and their analogues on the local economy and ecosystem health, given the increase in P. reticulatum blooms predicted for NW Patagonia in the context of a changing climate. [Display omitted] •Protoceratium reticulatum reached a maximum cell density of 407,000 cells L−1 in integrated tube samples (0–10 m).•First report of YTX levels in mussels exceeding the regulatory limit in Chile.•A maximum yessotoxin of 9.42 mg YTX kg−1 was detected in native populations of Mytilus chilensis.•Five different YTX analogues were identified.•Investigate accumulation and detoxification processes were followed over a 1-year period.