Department of Biology, Mount Allison University, New Brunswick, NJ E4L 1E4, Canada.
U.S. Food and Drug Administration, Dauphin Island, Alabama, AL 36528, USA.
Toxins (Basel). 2021 Jun 10;13(6):413. doi: 10.3390/toxins13060413.
Ciguatera poisoning (CP) poses a significant threat to ecosystem services and fishery resources in coastal communities. The CP-causative ciguatoxins (CTXs) are produced by benthic dinoflagellates including and spp., and enter reef food webs via grazing on macroalgal substrates. In this study, we report on a 3-year monthly time series in St. Thomas, US Virgin Islands where spp. abundance and Caribbean-CTX toxicity in benthic samples were compared to key environmental factors, including temperature, salinity, nutrients, benthic cover, and physical data. We found that peak abundance occurred in summer while CTX-specific toxicity peaked in cooler months (February-May) when the mean water temperatures were approximately 26-28 °C. These trends were most evident at deeper offshore sites where macroalgal cover was highest year-round. Other environmental parameters were not correlated with the CTX variability observed over time. The asynchrony between spp. abundance and toxicity reflects potential differences in toxin cell quotas among species with concomitant variability in their abundances throughout the year. These results have significant implications for monitoring and management of benthic harmful algal blooms and highlights potential seasonal and highly-localized pulses in reef toxin loads that may be transferred to higher trophic levels.
雪卡毒素中毒（CP）对沿海社区的生态系统服务和渔业资源构成重大威胁。CP 致病雪卡毒素（CTXs）由底栖腰鞭毛藻属包括 和 等产生，并通过摄食大型藻类基质进入珊瑚礁食物网。在这项研究中，我们报告了美国维尔京群岛圣托马斯的一项为期 3 年的每月时间序列，比较了底栖样本中的 spp. 丰度和加勒比海 CTX 毒性与关键环境因素，包括温度、盐度、营养物质、底栖覆盖和物理数据。我们发现， spp. 的丰度峰值出现在夏季，而 CTX 特异性毒性在水温约为 26-28°C 的较冷月份（二月至五月）达到峰值。这些趋势在全年大型藻类覆盖率最高的近海深水区最为明显。其他环境参数与随时间观察到的 CTX 变化无关。 spp. 丰度和毒性的不同步反映了不同 物种之间毒素细胞丰度的潜在差异，以及它们全年丰度的变化。这些结果对底栖有害藻类水华的监测和管理具有重要意义，并强调了珊瑚礁毒素负荷可能转移到更高营养级的潜在季节性和高度局部化的脉冲。
