Harmful algal bloom events are increasing in a number of water bodies around the world with significant economic impacts on the aquaculture, fishing and tourism industries. As well as their potential impacts on human health, toxin exposure from harmful algal blooms (HABs) has resulted in widespread morbidity and mortality in marine life, including top marine predators. There is therefore a need for an improved understanding of the trophic transfer, and persistence of toxins in marine food webs. For the first time, the concentrations of two toxin groups of commercial and environmental importance, domoic acid (DA) and saxitoxin (including Paralytic Shellfish Toxin (PST) analogues), were measured in the viscera of 40 different fish species caught in Scotland between February and November, 2012 to 2019. Overall, fish had higher concentrations of DA compared to PSTs, with a peak in the summer / autumn months. Whole fish concentrations were highest in pelagic species including Atlantic mackerel and herring, key forage fish for marine predators including seals, cetaceans and seabirds. The highest DA concentrations were measured along the east coast of Scotland and in Orkney. PSTs showed highest concentrations in early summer, consistent with phytoplankton bloom timings. The detection of multiple toxins in such a range of demersal, pelagic and benthic fish prey species suggests that both the fish, and by extension, piscivorous marine predators, experience multiple routes of toxin exposure. Risk assessment models to understand the impacts of exposure to HAB toxins on marine predators therefore need to consider how chronic, low-dose exposure to multiple toxins, as well as acute exposure during a bloom, could lead to potential long-term health effects ultimately contributing to mortalities. The potential synergistic, neurotoxic and physiological effects of long-term exposure to multiple toxins require investigation in order to appropriately assess the risks of HAB toxins to fish as well as their predators.

中文翻译：

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来自苏格兰沿海水域鱼类中有害藻类的毒素。

有害藻华事件在世界各地的许多水体中不断增加，对水产养殖、渔业和旅游业产生重大经济影响。除了对人类健康的潜在影响外，有害藻华 (HAB) 的毒素暴露导致海洋生物（包括顶级海洋捕食者）普遍发病和死亡。因此，需要更好地了解海洋食物网中毒素的营养转移和持久性。首次在 2 月期间在苏格兰捕获的 40 种不同鱼类的内脏中测量了两种具有商业和环境重要性的毒素组的浓度，软骨藻酸 (DA) 和石房蛤毒素（包括麻痹性贝类毒素 (PST) 类似物）和 2012 年 11 月至 2019 年。总体而言，与 PST 相比，鱼的 DA 浓度更高，在夏季/秋季达到峰值。全鱼浓度在远洋物种中最高，包括大西洋鲭鱼和鲱鱼，它们是海豹、鲸类和海鸟等海洋捕食者的主要饲料鱼。沿苏格兰东海岸和奥克尼群岛测得的 DA 浓度最高。PST 在初夏显示出最高浓度，与浮游植物开花时间一致。在如此广泛的底层、中上层和底栖鱼类猎物物种中检测到多种毒素表明，鱼类以及食鱼海洋捕食者都经历了多种毒素暴露途径。因此，用于了解暴露于 HAB 毒素对海洋捕食者的影响的风险评估模型需要考虑如何长期、低剂量地暴露于多种毒素，以及开花期间的急性暴露，可能导致潜在的长期健康影响，最终导致死亡。长期接触多种毒素的潜在协同效应、神经毒性和生理效应需要进行调查，以适当评估 HAB 毒素对鱼类及其捕食者的风险。