Research Project 1

雪卡特拉鱼中毒(CFP)，是全球最常见的鱼媒疾病，影响到数十名 每年数以千计的人，是由冈比亚盘藻属的甲鞭毛虫引起的。我们的目标是 研究气候变化，特别是变暖的海洋表面温度，将如何影响地理 产毒冈比亚圆盘吸虫的种群动态和程度在大加勒比地区 (GCR)，并使用这些发现来模拟在预测的气候下进入珊瑚礁食物网的雪卡毒素通量 改变情景。这项建议建立在我们以前工作的几个重要发现的基础上，包括 确定GCR的毒性与几个冈比亚圆盘动物物种密切相关，并且 大多数有毒物种G.Silvae可能是加勒比海珊瑚礁上的“超级细菌”，对大部分毒素负有责任 即使在低细胞密度的情况下也能进入食物网。这一突破性的发现提供了一个偶然的机会 研究这种高度产毒的物种的生理、毒性和生态，包括它的温度 以及它向其他地区扩散和殖民的方式。这其中的科学前提是 该项目只有通过深入了解最有毒物种的自闭学和它们的直接 以及对气候变化的间接反应(例如，海洋表面温度变暖和珊瑚礁冲击， )，我们(社会)是否能够恰当地评估和应对气候变化对CFP的影响 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， 包括对冈比亚亚种群内的局部适应和亚种群之间的扩散进行实地调查 应用RADSEQ(限制性内切酶相关DNA测序法)分析 产毒冈比亚圆盘藻。除了调查大范围的地理模式外，我们还将使用 邻近地点之间的自然温差，以探索极端温度的影响 和变异性对冈比亚群落的组成。这些自然实验将是 辅以实验室研究，以确定产生毒素的冈比亚圆盘藻的复原力。到热的 变温状态下的应力。总而言之，这些数据将揭示温度如何驱动 冈比亚群落的划分在地方、区域和季节范围内进行。这个有很大的 气候驱动的气候变暖对雪卡特拉的范围和流行的影响 GCR的毒性。所产生的数据，以及RP2和RP3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计算雪卡毒素通量的模型 在食物网中。这一建模工作将推进CFP事件预测能力的界限 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.