Domoic acid (DA) and saxitoxin (STX)-producing algae are present in Alaskan seas, presenting exposure risks to marine mammals that may be increasing due to climate change. To investigate potential increases in exposure risks to four pagophilic ice seal species (Erignathus barbatus, bearded seals; Pusa hispida, ringed seals; Phoca largha, spotted seals; and Histriophoca fasciata, ribbon seals), this study analyzed samples from 998 seals harvested for subsistence purposes in western and northern Alaska during 2005–2019 for DA and STX. Both toxins were detected in bearded, ringed, and spotted seals, though no clinical signs of acute neurotoxicity were reported in harvested seals. Bearded seals had the highest prevalence of each toxin, followed by ringed seals. Bearded seal stomach content samples from the Bering Sea showed a significant increase in DA prevalence with time (logistic regression, p = .004). These findings are consistent with predicted northward expansion of DA-producing algae. A comparison of paired samples taken from the stomachs and colons of 15 seals found that colon content consistently had higher concentrations of both toxins. Collectively, these results suggest that ice seals, particularly bearded seals (benthic foraging specialists), are suitable sentinels for monitoring HAB prevalence in the Pacific Arctic and subarctic.

中文翻译：

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冰封作为太平洋北极和亚北极海洋生态系统中藻类毒素存在的哨兵

阿拉斯加海域存在产生软骨藻酸 (DA) 和石房蛤毒素 (STX) 的藻类，给海洋哺乳动物带来的暴露风险可能会因气候变化而增加。调查四种嗜食冰海豹物种（ Erignathus barbatus，胡须海豹；Pusa hispida，环斑海豹；Phoca largha，斑点海豹；和Histriophoca fasciata）暴露风险的潜在增加，带状海豹），本研究分析了 2005 年至 2019 年期间在阿拉斯加西部和北部为生存目的收获的 998 只海豹的 DA 和 STX 样本。在胡须、环斑和斑点海豹中都检测到了这两种毒素，尽管在收获的海豹中没有报告急性神经毒性的临床症状。胡须海豹每种毒素的流行率最高，其次是环斑海豹。来自白令海的胡须海豹胃内容物样本显示 DA 患病率随时间显着增加（逻辑回归，p = .004)。这些发现与预测的产生 DA 的藻类向北扩张一致。对取自 15 只海豹的胃和结肠的配对样本进行比较后发现，结肠内容物的两种毒素浓度始终较高。总的来说，这些结果表明，冰海豹，尤其是胡须海豹（底栖觅食专家），是监测太平洋北极和亚北极地区 HAB 流行率的合适哨兵。