Saxitoxin and tetrodotoxin bioavailability increases in future oceans
Saxitoxin and tetrodotoxin bioavailability increases in future oceans
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DOI：
10.1038/s41558-019-0589-3
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发表时间：
2019-11-01
影响因子：
30.7
通讯作者：
Hardege, J. D.
中科院分区：
文献类型：
--
作者：
Roggatz, C. C.;Fletcher, N.;Hardege, J. D.
增加的大气CO2水平主要被海洋吸收，降低地表水pH值（1）。结合海洋温度的升高，这些变化已被确定为对未来海洋生物的主要可持续性威胁。已知海洋生物之间的相互作用取决于生物分子，尽管海洋pH值对其生物利用度和功能的影响尚未探索。在这里，我们展示了全球变化对海洋中的两种生态关键分子，麻痹性神经毒素石房蛤毒素和河豚毒素的重大影响。温度升高和pH值下降增加了水中有毒形式的丰度。我们的地理空间全球模型预测，这种毒性的增加可能会加剧有害藻华的破坏性影响，例如通过增加麻痹性贝类中毒的发生率。对阿拉斯加蛤蚌中石房蛤毒素毒性水平的未来计算显示，石房蛤毒素的毒性水平已达到安全食用的极限。我们对石房蛤毒素和河豚毒素的研究结果表明，pH值和温度的变化对溶解在海洋中的化学物质有潜在的影响。这不仅揭示了生态毒理学的重要意义，而且还揭示了介导物种相互作用的化学信号，如觅食，繁殖或捕食在海洋中，对生态系统稳定性和生态系统服务的未探索的后果。
Increasing atmospheric CO2 levels are largely absorbed by the ocean, decreasing surface water pH(1). In combination with increasing ocean temperatures, these changes have been identified as a major sustainability threat to future marine life(2). Interactions between marine organisms are known to depend on biomolecules, although the influence of oceanic pH on their bioavailability and functionality remains unexplored. Here we show that global change substantially impacts two ecological keystone molecules(3) in the ocean, the paralytic neurotoxins saxitoxin and tetrodotoxin. Increasing temperatures and declining pH increase the abundance of their toxic forms in the water. Our geospatial global model predicts where this increased toxicity could intensify the devastating impact of harmful algal blooms, for example through an increased incidence of paralytic shellfish poisoning. Calculations of future saxitoxin toxicity levels in Alaskan clams, Saxidomus gigantea, show critical exceedance of limits safe for consumption. Our findings for saxitoxin and tetrodotoxin exemplify potential consequences of changing pH and temperature on chemicals dissolved in the sea. This reveals major implications not only for ecotoxicology, but also for chemical signals that mediate species interactions such as foraging, reproduction or predation in the ocean, with unexplored consequences for ecosystem stability and ecosystem services.