Research Project 1

雪卡毒鱼中毒（CFP）是全球最常见的鱼类传播疾病，影响数十个国家， 每年有数千人死亡，是由Gambierdiscus属的腰鞭毛虫引起的。我们的目标是 调查气候变化，特别是海洋表面温度的变暖，将如何影响地理 产毒冈比亚盘菌的范围和种群动态大加勒比区域 (GCR)，并利用这些发现来模拟在预测气候下雪卡毒素流入珊瑚礁食物网的情况 改变场景这项建议建立在我们以前工作的几个重要发现的基础上，其中包括 确定GCR的毒性与少数几种Gambierdiscus物种密切相关， 毒性最强的种G.海蛞蝓可能是加勒比海珊瑚礁上的“超级细菌”， 即使在低细胞密度下也能进入食物网。这一突破性的发现提供了一个偶然的机会 研究这种高度繁殖的物种的生理学、毒性和生态学，包括它的温度 容忍度以及它扩散到其他地区并殖民化的方式。科学的前提是 项目的目的是，只有通过深入了解最有毒物种的个体生态学及其直接影响， 和对气候变化的间接反应（例如，海洋表面温度上升和珊瑚礁的影响， 我们（社会）是否能够正确评估和应对气候变化对CFP的影响 在GCR的发病率。我们将使用创新的实验方法来研究温度的影响， 包括实地调查当地的适应性内和传播冈比亚discus亚种群 使用RADseq（限制性位点相关DNA测序）和时空动态分析， 产毒甘比盘菌除了调查广泛的地理模式，我们将使用 邻近地点之间的自然温差，以探索极端温度的影响 和变异性的组成Gambierdiscus社区。这些自然实验将是 辅以实验室研究，以确定产毒甘比盘菌属的恢复力。热 在不同温度条件下的应力。总之，这些数据将揭示温度驱动的 Gambierdiscus社区的划分在当地，区域和季节尺度上运作。这是主要的 关于气候驱动的变暖对雪卡毒的程度和流行的影响的含义 大中华区的毒性由此产生的数据，沿着在RP 2和RP 3中产生的数据，将使我们能够进一步 开发和校准我们的雪卡毒素通量模型，这是有史以来第一个雪卡毒素通量的计算模型 在食物网中。这种建模工作将推动CFP事件预测能力的边界 和公共卫生保护。

Ciguatera fish poisoning (CFP), the most common form of finfish-borne disease globally, affecting tens of thousands of people each year, is caused by dinoflagellates in the genus Gambierdiscus. Our goal is to investigate how climate change, particularly warming sea surface temperatures, will influence the geographic extent and population dynamics of toxin-producing Gambierdiscus spp. in the Greater Caribbean Region (GCR), and use these findings to model ciguatoxin fluxes into coral reef food webs under predicted climate change scenarios. This proposal builds on several important findings from our previous work, which includes the determination that toxicity in the GCR is tightly linked to just a few Gambierdiscus species, and that the most toxic species G. silvae may be the “super bug” on Caribbean reefs, responsible for the bulk of toxin entering the food web even at low cell densities. This breakthrough discovery presents a fortuitous opportunity to study the physiology, toxicity, and ecology of this highly toxigenic species, including its temperature tolerances and the manner in which it disperses to and colonizes other regions. The scientific premise of this project is that only through a deep understanding of the autecology of the most toxic species and their direct and indirect responses to climate change (e.g., warming sea surface temperatures and coral reef impacts, respectively), will we (society) be able to properly assess and respond to the impact of climate change on CFP incidence in the GCR. We will use innovative experimental approaches to examine the impacts of temperature, including field investigations of local adaptation within and dispersal between Gambierdiscus sub-populations using RADseq (Restriction site-Associated DNA sequencing) and analyses of the spatio-temporal dynamics of toxin-producing Gambierdiscus spp. In addition to investigating broad-scale geographic patterns, we will use natural temperature differences between closely adjacent sites to explore the effects of temperature extremes and variability on the composition of Gambierdiscus communities. These natural experiments will be complemented by laboratory studies to determine resilience of toxin-producing Gambierdiscus spp. to thermal stress under variable temperature regimes. Together, these data will reveal how temperature-driven partitioning of Gambierdiscus communities operates at local, regional, and seasonal scales. This has major implications with respect to the effects of climate-driven warming on the extent and prevalence of ciguatera toxicity in the GCR. The resulting data, along with that produced in RP2 and RP3, will enable us to further develop and calibrate our ciguatoxin flux model, which is the first-ever computational model of ciguatoxin fluxes in the food web. This modeling effort will push forward the boundaries of predictive capacity for CFP events and public health protection.