As harmful algal blooms (HABs) increase in magnitude and duration worldwide, they are becoming an expanding threat to marine wildlife. Over the past decade, blooms of algae that produce the neurotoxins domoic acid (DA) and saxitoxin (STX) and documented concurrent seabird mortality events have increased bicoastally in the United States. We conducted a retrospective analysis of HAB related mortality events in California, Washington, and Rhode Island between 2007 and 2018 involving 12 species of seabirds, to document the levels, ranges, and patterns of DA and STX in eight sample types (kidney, liver, stomach, intestinal, cloacal, cecal contents, bile, blood) collected from birds during these events. Samples (n = 182) from 83 birds were examined for DA (n = 135) or STX (n = 17) or both toxins simultaneously (n = 30), using ELISA or LCMS at the National Oceanographic and Atmospheric Administration, National Marine Fisheries Service (NOAA-NMFS) Wildlife Algal-toxin Research and Response Network (WARRN-West) or the University of California, Santa Cruz (UCSC). DA or STX was detected in seven of the sample types with STX below the minimum detection limit in blood for the three samples tested. DA was found in 70% and STX was found in 23% of all tested samples. The ranges of detectable levels of DA and STX in all samples were 0.65–681,190.00 ng g⁻¹ and 2.00–20.95 ng g⁻¹, respectively. Cloacal contents from a Pacific loon (Gavia pacifica) collected in 2017 from Ventura County, California, had the highest maximum level of DA for all samples and species tested in this study. The highest level of STX for all samples and species was detected in the bile of a northern fulmar (Fulmarus glacialis) collected in 2018 from San Luis Obispo County, California. DA detections were consistently found in gastrointestinal samples, liver, bile, and kidney, whereas STX detections were most frequently seen in liver and bile samples. Co-occurring HAB toxins (DA and STX) were detected in white-winged scoters (Melanitta deglandi) in 2009, a Brandt's cormorant (Phalacrocorax penicillatus) in 2015, and a northern fulmar and common murre (Uria aalge) in 2018. This article provides DA and STX tissue concentrations and patterns in avian samples and shows the utility of various sample types for the detection of HAB toxins. Future research to understand the pharmacodynamics of these toxins in avian species and to establish lethal doses in various bird species would be beneficial.

随着全球范围内有害藻华（HAB）的数量和持续时间的增加，它们正日益对海洋野生生物构成威胁。在过去的十年中，在美国，产生神经毒素多摩酸（DA）和沙门毒素（STX）的藻类大量繁殖，并记录了同时发生的海鸟死亡率事件。我们对2007年至2018年在加利福尼亚，华盛顿和罗德岛发生的与HAB相关的死亡事件进行了回顾性分析，涉及12种海鸟，以记录八种样本类型（肾脏，肝脏，在这些事件中从鸟类收集的胃，肠，泄殖腔，盲肠内容物，胆汁，血液）。检查了83只禽类的样本（n  = 182 ）的DA（n = 135）或STX（n  = 17）或同时存在两种毒素（n  = 30），使用国家海洋和大气管理局，国家海洋渔业局（NOAA-NMFS）野生生物藻毒素研究与反应网络（ELISA）或LCMS WARRN-West）或加利福尼亚大学圣克鲁斯分校（UCSC）。在三种样本中，STX低于血液中最低检出限的7种样本中检测到DA或STX。在所有测试样品中，发现DA的比例为70％，发现STX的比例为23％。所有样品中DA和STX的可检测水平范围分别为0.65–681,190.00 ng g ^-1和2.00–20.95 ng g ^-1。太平洋龙虾（Gavia pacifica）的泄殖腔内容物于2017年从加利福尼亚州文图拉县采集的）在本研究中测试的所有样品和物种中，DA的最高最高含量最高。在2018年从加利福尼亚州圣路易斯·奥比斯波县采集的北方（Fulmarus glacialis）的胆汁中检测到所有样本和物种的STX含量最高。在胃肠道样本，肝，胆汁和肾脏中始终可以找到DA检测，而在肝和胆汁样本中最常见的是STX检测。共检测到HAB毒素（DA和STX）于2009年在白翅苏格兰人（Melanitta deglandi），2015年勃兰特氏（（Phalacrocorax penicillatus），北部ful和常见（Uria aalge）中被检测到）在2018年。本文提供了禽类样品中DA和STX组织的浓度和模式，并展示了各种样品类型在检测HAB毒素中的效用。进一步研究以了解这些毒素在禽类中的药效学并确定各种鸟类的致死剂量将是有益的。