Determination of phycotoxins and toxigenic dinoflagellates abundance during R/V Coriolis II cruise in February 2014

The occurrence of harmful algal blooms (HABs) is a global problem, and particularly in San Jorge Gulf (SJG), Argentina, which supports important fisheries, HABs represent a risk to human health. We studied the diversity and distribution of toxigenic dinoflagellates in the SJG using toxin detection and quantification, and assessed the connections between cell densities, toxins, and oceanographic parameters. Phytoplankton net samples were taken for microscopic and liquid chromatography-​tandem mass spectrometry (LC-MSMS) analyses during an expedition aboard R/V Coriolis II in February 2014. Solid phase adsorption toxin tracking (SPATT) devices were also deployed to determine the presence of dissolved lipophilic toxins in seawater. Toxigenic dinoflagellate species and associated toxins showed different distribution patterns in the north and the south SJG. Protoceratium reticulatum and Dinophysis acuminata, together with yessotoxin and pectenotoxins, were predominantly detected in the northern SJG, mainly associated with low-nutrient, warmer waters. By contrast, Alexandrium catenella and paralytic shellfish toxins showed the highest relative abundances in the southern SJG, associated with high-nutrient, low-temperature waters. Cellular toxin content was also differently affected by environmental parameters, highlighting the complexity of HABs in this area. Spirolides were detected by SPATT for the first time in the SJG, suggesting the occurrence of A. ostenfeldii.

有害藻华（harmful algal blooms, HABs）的暴发是全球性环境问题，在拥有重要渔业产业的阿根廷圣豪尔赫湾（San Jorge Gulf, SJG），有害藻华更是对人类健康构成显著威胁。本研究采用毒素检测与定量技术，对圣豪尔赫湾产毒甲藻的多样性与分布特征开展系统调研，并评估了细胞密度、毒素含量与海洋环境参数之间的内在关联。2014年2月，研究团队搭乘“科里奥利二世号”（R/V Coriolis II）考察船执行科考任务，期间采集浮游植物网样，用于显微镜镜检与液相色谱-串联质谱（LC-MSMS）分析；同时部署固相吸附毒素追踪（solid phase adsorption toxin tracking, SPATT）装置，以监测海水中溶解性脂溶性毒素的存在情况。研究结果显示，产毒甲藻物种及其关联毒素在圣豪尔赫湾南北区域呈现出截然不同的分布格局。网状原角藻（Protoceratium reticulatum）与尖鳍藻（Dinophysis acuminata），连同虾夷扇贝毒素（yessotoxin）与扇贝毒素（pectenotoxins），主要在圣豪尔赫湾北部被检出，且多与低营养盐、水温偏高的水体环境密切相关。与之形成鲜明对照的是，链状亚历山大藻（Alexandrium catenella）与麻痹性贝类毒素（paralytic shellfish toxins）在圣豪尔赫湾南部的相对丰度最高，其分布与高营养盐、低温的水体环境显著相关。此外，环境参数对细胞毒素含量的调控作用也存在显著差异，这进一步凸显了该区域有害藻华生态过程的复杂性。本研究还首次通过SPATT装置在圣豪尔赫湾检测到螺旋藻毒素（spirolides），提示该区域存在奥氏亚历山大藻（A. ostenfeldii）的暴发风险。