Centro de Estudos do Mar, Universidade Federal do Paraná. P.O. Box 61. Pontal do Paraná, PR, 83255-976, Brazil.
Centro de Estudos do Mar, Universidade Federal do Paraná. P.O. Box 61. Pontal do Paraná, PR, 83255-976, Brazil.
Harmful Algae. 2019 Nov;89:101662. doi: 10.1016/j.hal.2019.101662. Epub 2019 Sep 20.
On June 2016, a major bloom of Dinophysis acuminata complex was noticed over the coast of Paraná State (PR), southern Brazil, an area unprotected by any official monitoring program. Here we report the results of an extensive sampling effort that ultimately led PR authorities to issue the first State shellfish-harvesting ban due to multi-species okadaic acid (OA) contamination. During its peak, the bloom covered an area of 201 km (∼2.0-3.5 × 54.0 km), attaining unprecedentedly high cell densities along the shallow (<15 m) continental shelf (mean 2.2 × 10, maximum 2.1 × 10 cells L) and adjacent sandy beaches (mean 2.8 × 10, maximum 5.2 × 10 cells L). Only OA was detected in suspension (max. 188 ng L). Toxin levels measured in bivalves were several times greater than the regulatory limit of 160 ng g, reaching up to 3600 ng g in Crassostrea gasar, by far the highest OA concentrations ever reported in oysters worldwide, 7700 ng g in brown mussels, Perna perna, and lower levels in clams, Anomalocardia brasiliana, and mangrove mussels, Mytella spp. Nine cases of human intoxication were officially reported and five people were hospitalized with typical symptoms of Diarrhetic Shellfish Poisoning linked to the consumption of contaminated bivalves. All bivalves quickly converted most of the OA into its esterified form, DTX-3, and eliminated the toxins only a few weeks following the bloom, with C. gasar being the slowest-detoxifying species. Lower OA levels were accumulated in zooplankton, gastropods and several novel toxin vectors, including benthic organisms such as sand dollars Mellita quinquiesperforata and the ghost-shrimp Callichirus major, which may act as a good indicator of the presence of toxins in sandy beaches, and pelagic fish species that can serve as potential alternative sources of OA to humans (Chaetodipterus faber and Mugil liza). Monitoring toxin contamination in seafood other than bivalves is thus recommended to ensure comprehensive human health protection during massive Dinophysis blooms. Additionally, since OA was also present at low concentrations in the liver of Guiana dolphins Sotalia guianensis and penguins Spheniscus magellanicus, exposure to biotoxins should be considered in conservation actions involving threatened and near-threatened marine organisms in this region.
2016 年 6 月，在巴西南部的巴拉那州（PR）沿海地区发现了大量的拟菱形藻复合种的大量繁殖，该地区没有任何官方监测计划的保护。在这里，我们报告了一项广泛采样工作的结果，该工作最终导致 PR 当局发布了由于多种物种 okadaic 酸（OA）污染而导致的首次州贝类捕捞禁令。在其高峰期，该藻华覆盖了 201 公里（∼2.0-3.5×54.0 公里）的区域，在浅滩（<15 米）大陆架上达到了前所未有的高细胞密度（平均 2.2×10，最大 2.1×10 个细胞 L）和相邻的沙滩（平均 2.8×10，最大 5.2×10 个细胞 L）。仅在悬浮液中检测到 OA（最大 188ng L）。贝类中测量的毒素水平是监管限值的 160ng g 的数倍，在 Gasar 贻贝中达到了 3600ng g，这是迄今为止在全球牡蛎中报告的最高 OA 浓度，在棕色贻贝、Perna perna 中为 7700ng g，在蛤、Anomalocardia brasiliana 和红树林贻贝中为较低水平。正式报告了九例人类中毒病例，有五人因食用受污染的贝类而住院，出现典型的腹泻性贝类中毒症状。所有贝类在藻华结束后的几周内迅速将大部分 OA 转化为其酯化形式 DTX-3，并消除了毒素，而 Gasar 贻贝是解毒最慢的物种。OA 水平较低的藻类在浮游动物、腹足类动物和几种新的毒素载体中积累，包括有孔虫类生物如 Mellita quinquiesperforata 和 Callichirus major 的幽灵虾，它们可能是沙滩上存在毒素的良好指示物，以及可以作为人类 OA 潜在替代来源的远洋鱼类物种（Chaetodipterus faber 和 Mugil liza）。因此，建议除了贝类之外，还应监测其他海鲜中的毒素污染，以确保在大规模拟菱形藻繁殖期间全面保护人类健康。此外，由于在瓜纳亚那海豚 Sotalia guianensis 和企鹅 Spheniscus magellanicus 的肝脏中也存在低浓度的 OA，因此在涉及该地区受威胁和近威胁海洋生物的保护行动中，应考虑生物毒素的暴露。
