Abstract：
Harmful algal blooms (HABs) are a persistent and increasing problem globally, yet we still have limited knowledge about how they affect wildlife. Although semi-aquatic and aquatic amphibians and reptiles have experienced large declines and occupy environments where HABs are increasingly problematic, their vulnerability to HABs remains unclear. To inform monitoring, management, and future research, we conducted a literature review, synthesized the studies, and report on the mortality events describing effects of cyanotoxins from HABs on freshwater herpetofauna. Our review identified 37 unique studies and 71 endpoints (no-observed-effect and lowest-observed-effect concentrations) involving 11 amphibian and 3 reptile species worldwide. Responses varied widely among studies, species, and exposure concentrations used in experiments. Concentrations causing lethal and sublethal effects in laboratory experiments were generally 1 to 100 µg/L, which contains the mean value of reported HAB events but is 70 times less than the maximum cyanotoxin concentrations reported in the environment. However, one species of amphibian was tolerant to concentrations of 10,000 µg/L, demonstrating potentially immense differences in sensitivities. Most studies focused on microcystin-LR (MC-LR), which can increase systemic inflammation and harm the digestive system, reproductive organs, liver, kidneys, and development. The few studies on other cyanotoxins illustrated that effects resembled those of MC-LR at similar concentrations, but more research is needed to describe effects of other cyanotoxins and mixtures of cyanotoxins that commonly occur in the environment. All experimental studies were on larval and adult amphibians; there were no such studies on reptiles. Experimental work with reptiles and adult amphibians is needed to clarify thresholds of tolerance. Only nine mortality events were reported, mostly for reptiles. Given that amphibians likely decay faster than reptiles, which have tissues that resist decomposition, mass amphibian mortality events from HABs have likely been under-reported. We propose that future efforts should be focused on seven major areas, to enhance our understanding of effects and monitoring of HABs on herpetofauna that fill important roles in freshwater and terrestrial environments. Environ Toxicol Chem 2024;00:1-14. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
摘要：
有害藻华（HAB）是全球范围内持续存在且日益严重的问题，然而，我们对它们如何影响野生动物的知识仍然有限。尽管半水生和水生两栖动物和爬行动物经历了大幅下降，并占据了HAB问题越来越严重的环境，他们对HAB的脆弱性仍不清楚。通知监测，管理,和未来的研究，我们进行了文献综述，综合了这些研究，并报告了描述HABs的氰毒素对淡水爬虫的影响的死亡事件。我们的审查确定了37项独特的研究和71个终点（未观察到的影响和最低观察到的影响浓度），涉及全球11种两栖动物和3种爬行动物。研究之间的反应差异很大，物种,和实验中使用的暴露浓度。在实验室实验中引起致死和亚致死效应的浓度通常为1至100µg/L，其中包含报告的HAB事件的平均值，但比环境中报告的最大氰基毒素浓度低70倍。然而,一种两栖动物可以耐受10,000µg/L的浓度，展示潜在的巨大差异的敏感性。大多数研究集中在微囊藻毒素-LR（MC-LR），这会增加全身炎症并损害消化系统，生殖器官,肝脏,肾脏，和发展。对其他氰基毒素的少数研究表明，在相似浓度下，效果类似于MC-LR，但是需要更多的研究来描述环境中常见的其他氰基毒素和氰基毒素混合物的影响。所有实验研究都是针对幼虫和成年两栖动物；没有关于爬行动物的此类研究。需要对爬行动物和成年两栖动物进行实验，以阐明耐受阈值。仅报告了9起死亡事件，主要是爬行动物。鉴于两栖动物可能比爬行动物腐烂得更快，具有抵抗分解的组织，HABs引起的大规模两栖动物死亡事件可能被低估了。我们提出今后的工作重点要放在七个主要方面,加强我们对HAB对在淡水和陆地环境中发挥重要作用的爬虫的影响和监测的理解。环境毒物化学2024；00：1-14。已发布2024年。本文是美国政府的工作，是在美国的公共领域。WileyPeriodicalsLLC代表SETAC出版的环境毒理学和化学。
